Plants

16 pages, 5480 KiB

Open AccessEditor’s ChoiceArticle

Alginate Oligosaccharides Alleviate Salt Stress in Rice Seedlings by Regulating Cell Wall Metabolism to Maintain Cell Wall Structure and Improve Lodging Resistance

by Youwei Du, Huimin Zhao, Naijie Feng, Dianfeng Zheng, Aaqil Khan, Hang Zhou, Peng Deng, Yaxing Wang, Xutong Lu and Wenxin Jiang

Plants 2024, 13(9), 1215; https://doi.org/10.3390/plants13091215 - 28 Apr 2024

Cited by 4 | Viewed by 2389

Abstract

Salt stress is one of the major abiotic stresses that damage the structure and composition of cell walls. Alginate oligosaccharides (AOS) have been advocated to significantly improve plant stress tolerance. The metabolic mechanism by which AOS induces salt tolerance in rice cell walls [...] Read more.

Salt stress is one of the major abiotic stresses that damage the structure and composition of cell walls. Alginate oligosaccharides (AOS) have been advocated to significantly improve plant stress tolerance. The metabolic mechanism by which AOS induces salt tolerance in rice cell walls remains unclear. Here, we report the impact of AOS foliar application on the cell wall composition of rice seedlings using the salt-tolerant rice variety FL478 and the salt-sensitive variety IR29. Data revealed that salt stress decreased biomass, stem basal width, stem breaking strength, and lodging resistance; however, it increased cell wall thickness. In leaves, exogenous AOS up-regulated the expression level of OSCESA8, increased abscisic acid (ABA) and brassinosteroids (BR) content, and increased β-galacturonic activity, polygalacturonase activity, xylanase activity, laccase activity, biomass, and cellulose content. Moreover, AOS down-regulated the expression levels of OSMYB46 and OSIRX10 and decreased cell wall hemicellulose, pectin, and lignin content to maintain cell wall stability under salt stress. In stems, AOS increased phenylalamine ammonia-lyase and tyrosine ammonia-lyase activities, while decreasing cellulase, laccase, and β-glucanase activities. Furthermore, AOS improved the biomass and stem basal width and also enhanced the cellulose, pectin, and lignin content of the stem, As a result, increased resistance to stem breakage strength and alleviated salt stress-induced damage, thus enhancing the lodging resistance. Under salt stress, AOS regulates phytohormones and modifies cellulose, hemicellulose, lignin, and pectin metabolism to maintain cell wall structure and improve stem resistance to lodging. This study aims to alleviate salt stress damage to rice cell walls, enhance resistance to lodging, and improve salt tolerance in rice by exogenous application of AOS. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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37 pages, 1251 KiB

Open AccessEditor’s ChoiceReview

Prenylated Flavonoids of the Moraceae Family: A Comprehensive Review of Their Biological Activities

by Jaime Morante-Carriel, Suzana Živković, Hugo Nájera, Susana Sellés-Marchart, Ascensión Martínez-Márquez, María José Martínez-Esteso, Anna Obrebska, Antonio Samper-Herrero and Roque Bru-Martínez

Plants 2024, 13(9), 1211; https://doi.org/10.3390/plants13091211 - 27 Apr 2024

Cited by 9 | Viewed by 3453

Abstract

Prenylated flavonoids (PFs) are natural flavonoids with a prenylated side chain attached to the flavonoid skeleton. They have great potential for biological activities such as anti-diabetic, anti-cancer, antimicrobial, antioxidant, anti-inflammatory, enzyme inhibition, and anti-Alzheimer’s effects. Medicinal chemists have recently paid increasing attention to [...] Read more.

Prenylated flavonoids (PFs) are natural flavonoids with a prenylated side chain attached to the flavonoid skeleton. They have great potential for biological activities such as anti-diabetic, anti-cancer, antimicrobial, antioxidant, anti-inflammatory, enzyme inhibition, and anti-Alzheimer’s effects. Medicinal chemists have recently paid increasing attention to PFs, which have become vital for developing new therapeutic agents. PFs have quickly developed through isolation and semi- or full synthesis, proving their high value in medicinal chemistry research. This review comprehensively summarizes the research progress of PFs, including natural PFs from the Moraceae family and their pharmacological activities. This information provides a basis for the selective design and optimization of multifunctional PF derivatives to treat multifactorial diseases. Full article

(This article belongs to the Special Issue Secondary Metabolites in Plants)

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24 pages, 5150 KiB

Open AccessEditor’s ChoiceArticle

Phytochemical, In Vitro, In Vivo, and In Silico Research on the Extract of Ajuga chamaepitys (L.) Schreb.

by Elis Ionus, Verginica Schröder, Carmen Lidia Chiţescu, Laura Adriana Bucur, Carmen Elena Lupu, Denisa-Elena Dumitrescu, Liliana Popescu, Dragoș Paul Mihai, Octavian Tudorel Olaru, George Mihai Nițulescu, Rica Boscencu and Cerasela Elena Gîrd

Plants 2024, 13(9), 1192; https://doi.org/10.3390/plants13091192 - 25 Apr 2024

Cited by 4 | Viewed by 2428

Abstract

The present study focuses on the chemical characterization of a dry extract obtained from the species Ajuga chamaepitys (L.) Schreb, evaluating its antioxidant properties, toxicity, and in silico profile. Quantitative analysis of the dry extract revealed a notable amount of phytochemical compounds: 59.932 [...] Read more.

The present study focuses on the chemical characterization of a dry extract obtained from the species Ajuga chamaepitys (L.) Schreb, evaluating its antioxidant properties, toxicity, and in silico profile. Quantitative analysis of the dry extract revealed a notable amount of phytochemical compounds: 59.932 ± 21.167 mg rutin equivalents (mg REs)/g dry weight, 45.864 ± 4.434 mg chlorogenic acid equivalents (mg ChAEs)/g dry weight and, respectively, 83.307 ± 3.989 mg tannic acid equivalents (TAEs)/g dry weight. By UHPLC-HRMS/MS, the following were quantified as major compounds: caffeic acid (3253.8 μg/g extract) and kaempherol (3041.5 μg/g extract); more than 11 types of polyphenolic compounds were quantified (genistin 730.2 μg/g extract, naringenin 395 μg/g extract, apigenin 325.7 μg/g extract, galangin 283.3 μg/g extract, ferulic acid 254.3 μg/g extract, p-coumaric acid 198.2 μg/g extract, rutin 110.6 μg/g extract, chrysin 90.22 μg/g extract, syringic acid 84.2 μg/g extract, pinocembrin 32.7 μg/g extract, ellagic acid 18.2 μg/g extract). The antioxidant activity was in accordance with the amount of phytochemical compounds: IC₅₀DPPH = 483.6 ± 41.4 µg/mL, IC₅₀ABTS^•+ = 127.4 ± 20.2 µg/mL, and EC₅₀FRAP = 491.6 ± 2 µg/mL. On the larvae of Artemia sp., it was found that the extract has a low cytotoxic action. In silico studies have highlighted the possibility of inhibiting the activity of protein kinases CDK5 and GSK-3b for apigenin, galangin, and kaempferol, with possible utility for treating neurodegenerative pathologies and neuropathic pain. Further studies are warranted to confirm the predicted molecular mechanisms of action and to further investigate the therapeutic potential in animal models of neurological disorders. Full article

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20 pages, 4491 KiB

Open AccessEditor’s ChoiceArticle

Crop-Specific Responses to Cold Stress and Priming: Insights from Chlorophyll Fluorescence and Spectral Reflectance Analysis in Maize and Soybean

by Maja Mazur, Maja Matoša Kočar, Antun Jambrović, Aleksandra Sudarić, Mirna Volenik, Tomislav Duvnjak and Zvonimir Zdunić

Plants 2024, 13(9), 1204; https://doi.org/10.3390/plants13091204 - 25 Apr 2024

Cited by 9 | Viewed by 2316

Abstract

This study aimed to investigate the impact of cold stress and priming on photosynthesis in the early development of maize and soybean, crops with diverse photosynthetic pathways. The main objectives were to determine the effect of cold stress on chlorophyll a fluorescence parameters [...] Read more.

This study aimed to investigate the impact of cold stress and priming on photosynthesis in the early development of maize and soybean, crops with diverse photosynthetic pathways. The main objectives were to determine the effect of cold stress on chlorophyll a fluorescence parameters and spectral reflectance indices, to determine the effect of cold stress priming and possible stress memory and to determine the relationship between different parameters used in determining the stress response. Fourteen maize inbred lines and twelve soybean cultivars were subjected to control, cold stress, and priming followed by cold stress in a walk-in growth chamber. Measurements were conducted using a portable fluorometer and a handheld reflectance instrument. Cold stress induced an overall downregulation of PSII-related specific energy fluxes and efficiencies, the inactivation of RCs resulting in higher energy dissipation, and electron transport chain impairment in both crops. Spectral reflectance indices suggested cold stress resulted in pigment differences between crops. The effect of priming was more pronounced in maize than in soybean with mostly a cumulatively negative effect. However, priming stabilized the electron trapping efficiency and upregulated the electron transfer system in maize, indicating an adaptive response. Overall, this comprehensive analysis provides insights into the complex physiological responses of maize and soybean to cold stress, emphasizing the need for further genotype-specific cold stress response and priming effect research. Full article

(This article belongs to the Special Issue Adaptive Strategies of Plants to Stress Factors)

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28 pages, 14909 KiB

Open AccessEditor’s ChoiceArticle

A Regulatory Mechanism on Pathways: Modulating Roles of MYC2 and BBX21 in the Flavonoid Network

by Nan Li, Yunzhang Xu and Yingqing Lu

Plants 2024, 13(8), 1156; https://doi.org/10.3390/plants13081156 - 22 Apr 2024

Cited by 5 | Viewed by 3625

Abstract

Genes of metabolic pathways are individually or collectively regulated, often via unclear mechanisms. The anthocyanin pathway, well known for its regulation by the MYB/bHLH/WDR (MBW) complex but less well understood in its connections to MYC2, BBX21, SPL9, PIF3, and HY5, is investigated here [...] Read more.

Genes of metabolic pathways are individually or collectively regulated, often via unclear mechanisms. The anthocyanin pathway, well known for its regulation by the MYB/bHLH/WDR (MBW) complex but less well understood in its connections to MYC2, BBX21, SPL9, PIF3, and HY5, is investigated here for its direct links to the regulators. We show that MYC2 can activate the structural genes of the anthocyanin pathway but also suppress them (except F3′H) in both Arabidopsis and Oryza when a local MBW complex is present. BBX21 or SPL9 can activate all or part of the structural genes, respectively, but the effects can be largely overwritten by the local MBW complex. HY5 primarily influences expressions of the early genes (CHS, CHI, and F3H). TF-TF relationships can be complex here: PIF3, BBX21, or SPL9 can mildly activate MYC2; MYC2 physically interacts with the bHLH (GL3) of the MBW complex and/or competes with strong actions of BBX21 to lessen a stimulus to the anthocyanin pathway. The dual role of MYC2 in regulating the anthocyanin pathway and a similar role of BBX21 in regulating BAN reveal a network-level mechanism, in which pathways are modulated locally and competing interactions between modulators may tone down strong environmental signals before they reach the network. Full article

(This article belongs to the Special Issue New Insights into Plant Signaling Mechanisms in Biotic and Abiotic Stress)

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17 pages, 2133 KiB

Open AccessEditor’s ChoiceArticle

Arbuscular Mycorrhizal Fungi Improve the Performance of Tempranillo and Cabernet Sauvignon Facing Water Deficit under Current and Future Climatic Conditions

by Daria Kozikova, Inmaculada Pascual and Nieves Goicoechea

Plants 2024, 13(8), 1155; https://doi.org/10.3390/plants13081155 - 22 Apr 2024

Cited by 4 | Viewed by 1996

Abstract

Climate change (CC) threatens Mediterranean viticulture. Rhizospheric microorganisms may be crucial for the adaptation of plants to CC. Our objective was to assess whether the association of two grapevine varieties with arbuscular mycorrhizal fungi (AMF) increases grapevine’s resilience to environmental conditions that combine [...] Read more.

Climate change (CC) threatens Mediterranean viticulture. Rhizospheric microorganisms may be crucial for the adaptation of plants to CC. Our objective was to assess whether the association of two grapevine varieties with arbuscular mycorrhizal fungi (AMF) increases grapevine’s resilience to environmental conditions that combine elevated atmospheric CO₂, increased air temperatures, and water deficit. Tempranillo (T) and Cabernet Sauvignon (CS) plants, grafted onto R110 rootstocks, either inoculated (+M) or not (−M) with AMF, were grown in temperature-gradient greenhouses under two environmental conditions: (i) current conditions (ca. 400 ppm air CO₂ concentration plus ambient air temperature, CATA) and (ii) climate change conditions predicted by the year 2100 (700 ppm of CO₂ plus ambient air temperature +4 °C, CETE). From veraison to maturity, for plants of each variety, inoculation treatment and environmental conditions were also subjected to two levels of water availability: full irrigation (WW) or drought cycles (D). Therefore, the number of treatments applied to each grapevine variety was eight, resulting from the combination of two inoculation treatments (+M and −M), two environmental conditions (CATA and CETE), and two water availabilities (WW and D). In both grapevine varieties, early drought decreased leaf conductance and transpiration under both CATA and CETE conditions and more markedly in +M plants. Photosynthesis did not decrease very much, so the instantaneous water use efficiency (WUE) increased, especially in drought +M plants under CETE conditions. The increase in WUE coincided with a lower intercellular-to-atmospheric CO₂ concentration ratio and reduced plant hydraulic conductance. In the long term, mycorrhization induced changes in the stomatal anatomy under water deficit and CETE conditions: density increased in T and decreased in CS, with smaller stomata in the latter. Although some responses were genotype-dependent, the interaction of the rootstock with AMF appeared to be a key factor in the acclimation of the grapevine to water deficit under both current and future CO₂ and temperature conditions. Full article

(This article belongs to the Topic Effects of Climate Change on Viticulture (Grape))

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17 pages, 3668 KiB

Open AccessEditor’s ChoiceArticle

Changes in Growth and Heavy Metal and Phenolic Compound Accumulation in Buddleja cordata Cell Suspension Culture under Cu, Fe, Mn, and Zn Enrichment

by Alicia Monserrat Vazquez-Marquez, Antonio Bernabé-Antonio, José Correa-Basurto, Cristina Burrola-Aguilar, Carmen Zepeda-Gómez, Francisco Cruz-Sosa, Aurelio Nieto-Trujillo and María Elena Estrada-Zúñiga

Plants 2024, 13(8), 1147; https://doi.org/10.3390/plants13081147 - 19 Apr 2024

Cited by 3 | Viewed by 2032

Abstract

Buddleja cordata cell suspension cultures could be used as a tool for investigating the capabilities of this species to tolerate heavy metals (HMs) and for assessing the effects of HMs on the accumulation of phenolic compounds in this species. It grows in a [...] Read more.

Buddleja cordata cell suspension cultures could be used as a tool for investigating the capabilities of this species to tolerate heavy metals (HMs) and for assessing the effects of HMs on the accumulation of phenolic compounds in this species. It grows in a wide range of habitats in Mexico, including ultramafic soils, and mobilizes some HMs in the soil. The mobilization of these HMs has been associated with phenolic substances. In addition, this species is used in Mexican traditional medicine. In the present study, a B. cordata cell suspension culture was grown for 18 days in a culture medium enriched with Cu (0.03–0.25 mM), Fe (0.25–1.5 mM), Mn (0.5–3.0 mM), or Zn (0.5–2.0 mM) to determine the effects of these HMs on growth and HM accumulation. We also assessed the effects of the HMs on phenolic compound accumulation after 1 and 18 days of HM exposure. Cells were able to grow at almost all tested HM concentrations and accumulated significant amounts of each HM. The highest accumulation levels were as follows: 1160 mg Cu kg⁻¹, 6845 mg Fe kg⁻¹, 3770 mg Mn kg⁻¹, and 6581 mg Zn kg⁻¹. Phenolic compound accumulation was affected by the HM exposure time and corresponded to each HM and its concentration. Future research should analyze whole plants to determine the capabilities of Buddleja cordata to accumulate abnormally high amounts of HM and to evaluate the physiological impact of changes in the accumulation of phenolic compounds. Full article

(This article belongs to the Special Issue Abiotic Stress Responses in Plants)

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17 pages, 1790 KiB

Open AccessEditor’s ChoiceArticle

The Expression of Key Ethylene and Anthocyanin Biosynthetic Genes of ‘Honeycrisp’ Apples Subjected to the Combined Use of Reflective Groundcovers and Aminoethoxyvinylglycine in the Mid-Atlantic US

by Md Shipon Miah and Macarena Farcuh

Plants 2024, 13(8), 1141; https://doi.org/10.3390/plants13081141 - 19 Apr 2024

Cited by 5 | Viewed by 1837

Abstract

The decreased profitability of important apple cultivars, such as ‘Honeycrisp’, results from the poor red skin coloration and high fruit drop in the mid-Atlantic US. Apple red skin coloration is determined by the anthocyanin concentration. Reflective groundcovers promote red skin coloration, whereas aminoethoxyvinylglycine [...] Read more.

The decreased profitability of important apple cultivars, such as ‘Honeycrisp’, results from the poor red skin coloration and high fruit drop in the mid-Atlantic US. Apple red skin coloration is determined by the anthocyanin concentration. Reflective groundcovers promote red skin coloration, whereas aminoethoxyvinylglycine (AVG) decreases the ethylene production and fruit drop, thus reducing the coloration. Although our previous study showed that combinations of these practices impact the fruit quality and color, research is lacking regarding their effects at the gene and metabolite levels. In this work, for two years, we compared the differences in the internal ethylene concentration (IEC), red skin coloration, fruit drop, transcript accumulation of key ethylene and anthocyanin biosynthetic pathway-related genes, and total anthocyanin concentration of ‘Honeycrisp’ apples. The fruit was treated with combinations of reflective groundcover (Extenday) and AVG (130 mg L⁻¹) and was assessed throughout ripening. Extenday-only-treated fruit displayed the highest upregulation of ethylene and anthocyanin biosynthetic-related genes and of total anthocyanins, exceeding 50% blush, while boosting the IEC. In contrast, AVG significantly decreased the expression of key ethylene and anthocyanin biosynthetic-related genes and total anthocyanins, thus preventing apples from reaching 50% blush, while also decreasing the IEC and fruit drop. The combination of Extenday x AVG fine-tuned the transcript accumulation of ethylene and anthocyanin biosynthetic-related genes as well as the total anthocyanins, allowing the ‘Honeycrisp’ fruit to exceed 50% blush, while increasing the IEC moderately and reducing the fruit drop (as compared to Extenday-only and control), thus enhancing the fruit economic value. Full article

(This article belongs to the Special Issue Horticultural Plant Cultivation and Fruit Quality Enhancement)

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21 pages, 7388 KiB

Open AccessEditor’s ChoiceArticle

Understanding the Saffron Corm Development—Insights into Histological and Metabolic Aspects

by Claudia Pallotti, Begoña Renau-Morata, Loriana Cardone, Sergio G. Nebauer, Mireia Albiñana Palacios, Alba Rivas-Sendra, José M. Seguí-Simarro and Rosa V. Molina

Plants 2024, 13(8), 1125; https://doi.org/10.3390/plants13081125 - 17 Apr 2024

Cited by 5 | Viewed by 2888

Abstract

The reproduction of Crocus sativus L., a sterile triploid plant, is carried out exclusively through corms, whose size determines the saffron yield. The development of daughter corms (DC) is supported by photoassimilates supplied by the leaves as well as by the mother corms [...] Read more.

The reproduction of Crocus sativus L., a sterile triploid plant, is carried out exclusively through corms, whose size determines the saffron yield. The development of daughter corms (DC) is supported by photoassimilates supplied by the leaves as well as by the mother corms (MC). While biomass partitioning during DC development is well studied, growth dynamics in terms of cell number and size, the involved meristems, as well as carbohydrate partition and allocation, are not yet fully understood. We conducted a comprehensive study into saffron corm growth dynamics at the macroscopic and microscopic levels. Variations in carbohydrate content and enzymatic activities related to sucrose metabolism in sources and sinks were measured. Two key meristems were identified. One is involved in vascular connections between DC and MC. The other is a thickening meristem responsible for DC enlargement. This research explains how the previously described phases of corm growth correlate with variations in cell division, enlargement dynamics, and carbohydrate partitioning among organs. Results also elucidated that the end of DC growth relates to a significant drop in MC root biomass, limiting the water supply for the DC growth, and establishing the onset of leaf wilting. The lack of starch accumulation in aged leaf cells is noteworthy, as is the accumulation of lipids. We hypothesize a signaling role of sugars in DC growth initiation, stop, and leaf aging. Finally, we established a predominant role of sucrose synthase as a sucrolytic enzyme in the maintenance of the high flux of carbon for starch synthesis in DC. Together, the obtained results pave the way for the definition of strategies leading to better control of saffron corm development. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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32 pages, 6231 KiB

Open AccessEditor’s ChoiceArticle

Rising Temperatures, Falling Leaves: Predicting the Fate of Cyprus’s Endemic Oak under Climate and Land Use Change

by Konstantinos Kougioumoutzis, Ioannis Constantinou and Maria Panitsa

Plants 2024, 13(8), 1109; https://doi.org/10.3390/plants13081109 - 16 Apr 2024

Cited by 3 | Viewed by 2235

Abstract

Endemic island species face heightened extinction risk from climate-driven shifts, yet standard models often underestimate threat levels for those like Quercus alnifolia, an iconic Cypriot oak with pre-adaptations to aridity. Through species distribution modelling, we investigated the potential shifts in its distribution [...] Read more.

Endemic island species face heightened extinction risk from climate-driven shifts, yet standard models often underestimate threat levels for those like Quercus alnifolia, an iconic Cypriot oak with pre-adaptations to aridity. Through species distribution modelling, we investigated the potential shifts in its distribution under future climate and land-use change scenarios. Our approach uniquely combines dispersal constraints, detailed soil characteristics, hydrological factors, and anticipated soil erosion data, offering a comprehensive assessment of environmental suitability. We quantified the species’ sensitivity, exposure, and vulnerability to projected changes, conducting a preliminary IUCN extinction risk assessment according to Criteria A and B. Our projections uniformly predict range reductions, with a median decrease of 67.8% by the 2070s under the most extreme scenarios. Additionally, our research indicates Quercus alnifolia’s resilience to diverse erosion conditions and preference for relatively dry climates within a specific annual temperature range. The preliminary IUCN risk assessment designates Quercus alnifolia as Critically Endangered in the future, highlighting the need for focused conservation efforts. Climate and land-use changes are critical threats to the species’ survival, emphasising the importance of comprehensive modelling techniques and the urgent requirement for dedicated conservation measures to safeguard this iconic species. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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49 pages, 18874 KiB

Open AccessEditor’s ChoiceArticle

Morphological and Ultrastructural Features of Selected Epidendroideae Pollen Dispersal Units and New Insights into Their Chemical Nature

by Carola Purgina, Silvia Ulrich, Martina Weber and Friðgeir Grímsson

Plants 2024, 13(8), 1114; https://doi.org/10.3390/plants13081114 - 16 Apr 2024

Cited by 2 | Viewed by 1929

Abstract

Orchidaceae display enormous diversity in their flower morphology, which is particularly evident in their pollen dispersal units (pollinia, pollinaria). The packaging of pollen by elastoviscin leads to a great diversity of these morphologically and structurally complex pollen units. Despite being one of the [...] Read more.

Orchidaceae display enormous diversity in their flower morphology, which is particularly evident in their pollen dispersal units (pollinia, pollinaria). The packaging of pollen by elastoviscin leads to a great diversity of these morphologically and structurally complex pollen units. Despite being one of the most diverse angiosperm families, the available palynological data on orchids remain limited and sometimes contradicting. This study provides new insights into the pollen morphology and ultrastructure of five orchid species from the subfamily Epidendroideae, using combined light, scanning electron, and transmission electron microscopy. The aim was to compare the morphology and ultrastructure of pollen dispersal units and to elucidate the chemical nature of the pollen wall layers and of elastoviscin. Our combined light and electron microscopy investigation demonstrated the presence of six tetrad types even within a single pollinium, which is unique for orchids. The application of different staining methods confirmed the assumed lipidic nature of elastoviscin and the differences in its contrast and ultrastructure suggest a mixture of sticky materials with dissimilar chemical compositions. This study affirmed that sporopollenin is mostly restricted to the outer pollen grains of peripheral tetrads in compact and sectile pollinia, while inner tetrads exhibit highly reduced non-sporopollenin pollen walls. Full article

(This article belongs to the Section Plant Cell Biology)

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20 pages, 5567 KiB

Open AccessEditor’s ChoiceArticle

Effects of Short-Term Nitrogen Additions on Biomass and Soil Phytochemical Cycling in Alpine Grasslands of Tianshan, China

by Chao Liu, Junjie Liu, Juan Wang and Xiaoyu Ding

Plants 2024, 13(8), 1103; https://doi.org/10.3390/plants13081103 - 15 Apr 2024

Cited by 6 | Viewed by 2205

Abstract

The nitrogen deposition process, as an important phenomenon of global climate change and an important link in the nitrogen cycle, has had serious and far-reaching impacts on grassland ecosystems. This study aimed to investigate the survival adaptation strategies of plants of different functional [...] Read more.

The nitrogen deposition process, as an important phenomenon of global climate change and an important link in the nitrogen cycle, has had serious and far-reaching impacts on grassland ecosystems. This study aimed to investigate the survival adaptation strategies of plants of different functional groups under nitrogen deposition, and the study identified the following outcomes of differences in biomass changes by conducting in situ simulated nitrogen deposition experiments while integrating plant nutrient contents and soil physicochemical properties: (1) nitrogen addition enhanced the aboveground biomass of grassland communities, in which Poaceae were significantly affected by nitrogen addition. Additionally, nitrogen addition significantly influenced plant total nitrogen and total phosphorus; (2) nitrogen addition improved the plant growth environment, alleviated plant nitrogen limitation, and promoted plant phosphorus uptake; and (3) there was variability in the biomass responses of different functional groups to nitrogen addition. The level of nitrogen addition was the primary factor affecting differences in biomass changes, while nitrogen addition frequency was an important factor affecting changes in plant community structure. Full article

(This article belongs to the Topic The Effect of Climate Change on Crops and Natural Ecosystems, 2nd Volume)

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27 pages, 3216 KiB

Open AccessEditor’s ChoiceReview

Corchorus tridens L.: A Review of Its Botany, Phytochemistry, Nutritional Content and Pharmacological Properties

by Refilwe Given Kudumela, Thanyani Emelton Ramadwa, Neo Mokgadi Mametja and Tracy Madimabi Masebe

Plants 2024, 13(8), 1096; https://doi.org/10.3390/plants13081096 - 13 Apr 2024

Cited by 3 | Viewed by 4136

Abstract

Phytotherapy is a cost-effective alternative that continues to evolve. This has sparked significant research interest in naturally occurring compounds found in edible plants that possess antibacterial, antioxidant, and anticancer properties. Corchorus tridens L. is a wild edible plant widely recognised for its edible [...] Read more.

Phytotherapy is a cost-effective alternative that continues to evolve. This has sparked significant research interest in naturally occurring compounds found in edible plants that possess antibacterial, antioxidant, and anticancer properties. Corchorus tridens L. is a wild edible plant widely recognised for its edible leaves, which are used for vegetable and animal feed. The plant is widely distributed across the African continent and is utilised in numerous countries for treating fever, pain, inflammation, and sexually transmitted diseases. Extracts from various parts of this plant exhibit antimicrobial, antioxidant, and pesticidal properties. This plant is a rich source of amino acids, vitamins, essential fatty acids, proteins, and minerals, as well as secondary metabolites such as alkaloids, flavonoids, quinines, steroids, terpenoids, phenols, and tannins. Additional studies are still needed to determine other biological activities, such as anti-inflammatory activity, involvement in the treatment of measles, prevention of anaemia, and pain-relieving properties. The current review aims to provide information on the characteristics, distribution, nutritional content, bioactive compounds, traditional uses, and biological activities of the edible plant species C. tridens L. to stimulate further research interest to address the existing literature gaps concerning this plant. Full article

(This article belongs to the Special Issue Plant Extracts)

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40 pages, 1910 KiB

Open AccessEditor’s ChoiceReview

Anthriscus sylvestris—Noxious Weed or Sustainable Source of Bioactive Lignans?

by Sanja Berežni, Neda Mimica-Dukić, Gianniantonio Domina, Francesco Maria Raimondo and Dejan Orčić

Plants 2024, 13(8), 1087; https://doi.org/10.3390/plants13081087 - 12 Apr 2024

Cited by 3 | Viewed by 2410

Abstract

Anthriscus sylvestris (L.) Hoffm. (Apiaceae), commonly known as wild chervil, has gained scientific interest owing to its diverse phytochemical profile and potential therapeutic applications. The plant, despite being categorized as a noxious weed, is traditionally used in treating various conditions like headaches, dressing [...] Read more.

Anthriscus sylvestris (L.) Hoffm. (Apiaceae), commonly known as wild chervil, has gained scientific interest owing to its diverse phytochemical profile and potential therapeutic applications. The plant, despite being categorized as a noxious weed, is traditionally used in treating various conditions like headaches, dressing wounds, and as a tonic, antitussive, antipyretic, analgesic, and diuretic. Its pharmacological importance stems from containing diverse bioactive lignans, especially aryltetralins and dibenzylbutyrolactones. One of the main compounds of A. sylvestris, deoxypodophyllotoxin, among its wide-ranging effects, including antitumor, antiproliferative, antiplatelet aggregation, antiviral, anti-inflammatory, and insecticidal properties, serves as a pivotal precursor to epipodophyllotoxin, crucial in the semisynthesis of cytostatic agents like etoposide and teniposide. The main starting compound for these anticancer medicines was podophyllotoxin, intensively isolated from Sinopodophyllum hexandrum, now listed as an endangered species due to overexploitation. Since new species are being investigated as potential sources, A. sylvestris emerges as a highly promising candidate owing to its abundant lignan content. This review summarizes the current knowledge on A. sylvestris, investigating its biological and morphological characteristics, and pharmacological properties. Emphasizing the biological activities and structure–activity relationship, this review underscores its therapeutic potential, thus encouraging further exploration and utilization of this valuable plant resource. Full article

(This article belongs to the Special Issue Invasive Alien Plant Species: From Phytochemical Diversity to Ecological Management)

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15 pages, 4400 KiB

Open AccessEditor’s ChoiceArticle

Integration of Metabolomic and Transcriptomic Analyses Reveals the Molecular Mechanisms of Flower Color Formation in Prunus mume

by Ruyi Wang, Xin Yang, Tao Wang, Baohui Li, Ping Li and Qin Zhang

Plants 2024, 13(8), 1077; https://doi.org/10.3390/plants13081077 - 11 Apr 2024

Cited by 6 | Viewed by 1688

Abstract

Flower color is an important trait that affects the economic value of Prunus mume, a famous ornamental plant in the Rosaceae family. P. mume with purple–red flowers is uniquely charming and highly favored in landscape applications. However, little is known about its [...] Read more.

Flower color is an important trait that affects the economic value of Prunus mume, a famous ornamental plant in the Rosaceae family. P. mume with purple–red flowers is uniquely charming and highly favored in landscape applications. However, little is known about its flower coloring mechanism, which stands as a critical obstacle on the path to innovative breeding for P. mume flower color. In this study, transcriptomic and targeted metabolomic analyses of purple–red P. mume and white P. mume were performed to elucidate the mechanism of flower color formation. In addition, the expression patterns of key genes were analyzed using an RT-qPCR experiment. The results showed that the differential metabolites were significantly enriched in the flavonoid synthesis pathway. A total of 14 anthocyanins emerged as the pivotal metabolites responsible for the differences in flower color between the two P. mume cultivars, comprising seven cyanidin derivatives, five pelargonium derivatives, and two paeoniflorin derivatives. Moreover, the results clarified that the metabolic pathway determining flower color in purple–red P. mume encompasses two distinct branches: cyanidin and pelargonidin, excluding the delphinidin branch. Additionally, through the integrated analysis of transcriptomic and metabolomic data, we identified 18 key genes responsible for anthocyanin regulation, thereby constructing the gene regulatory network for P. mume anthocyanin synthesis. Among them, ten genes (PmCHI, PmGT2, PmGT5, PmGST3, PmMYB17, PmMYB22, PmMYB23, PmbHLH4, PmbHLH10, and PmbHLH20) related to anthocyanin synthesis were significantly positively correlated with anthocyanin contents, indicating that they may be the key contributors to anthocyanin accumulation. Our investigation contributes a novel perspective to understanding the mechanisms responsible for flower color formation in P. mume. The findings of this study introduce novel strategies for molecular design breeding aimed at manipulating flower color in P. mume. Full article

(This article belongs to the Special Issue Flower Germplasm Resource and Genetic Breeding)

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16 pages, 534 KiB

Open AccessEditor’s ChoiceArticle

Wild Edible Plants Used in Dalmatian Zagora (Croatia)

by Tonka Ninčević Runjić, Marija Jug-Dujaković, Marko Runjić and Łukasz Łuczaj

Plants 2024, 13(8), 1079; https://doi.org/10.3390/plants13081079 - 11 Apr 2024

Cited by 5 | Viewed by 2932

Abstract

Background: Dalmatian Zagora has experienced significant depopulation trends over recent decades. The area is very interesting because of its rich biodiversity of species as well as its history of the use of wild foods. Since there is a danger of permanent loss of [...] Read more.

Background: Dalmatian Zagora has experienced significant depopulation trends over recent decades. The area is very interesting because of its rich biodiversity of species as well as its history of the use of wild foods. Since there is a danger of permanent loss of knowledge on the use of wild edibles, we focused our research on recording traditions local to this area. Methods: We conducted interviews with 180 residents. Results: A record was made of 136 species of wild food plants and 22 species of edible mushrooms gathered in the area. The most frequently collected species are Rubus ulmifolius Schott, Cornus mas L., Portulaca oleracea L., Asparagus acutifolius L., Sonchus spp., Morus spp., Taraxacum spp., Amaranthus retroflexus L., Cichorium intybus L., and Dioscorea communis (L.) Caddick & Wilkin. Conclusions: The list of taxa used is typical for other (sub-)Mediterranean parts of Croatia; however, more fungi species are used. The most important finding of the paper is probably the recording of Legousia speculum-veneris (L.) Chaix, a wild vegetable used in the area. Full article

(This article belongs to the Special Issue New Insights into Ethnobotany and Ethnoecology)

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18 pages, 6068 KiB

Open AccessEditor’s ChoiceArticle

Effects of Supplemental Lighting on Flavonoid and Anthocyanin Biosynthesis in Strawberry Flesh Revealed via Metabolome and Transcriptome Co-Analysis

by Shen Chen, Xiaojing Wang, Yu Cheng, Hongsheng Gao and Xuehao Chen

Plants 2024, 13(8), 1070; https://doi.org/10.3390/plants13081070 - 10 Apr 2024

Cited by 8 | Viewed by 2269

Abstract

The spectral composition of light influences the biosynthesis of flavonoids in many plants. However, the detailed composition of flavonoids and anthocyanins and the molecular basis for their biosynthesis in strawberry fruits under two light-quality treatments, red light supplemented with blue light (RB) and [...] Read more.

The spectral composition of light influences the biosynthesis of flavonoids in many plants. However, the detailed composition of flavonoids and anthocyanins and the molecular basis for their biosynthesis in strawberry fruits under two light-quality treatments, red light supplemented with blue light (RB) and ultraviolet B (UVB) irradiation, remain unclear. In this study, the content of flavonoids and anthocyanins was significantly increased in strawberry fruits under RB light and UVB, respectively. The content of flavonoids and anthocyanins in strawberry fruits under UVB light was dramatically higher than that in strawberry fruits irradiated with RB light, and a total of 518 metabolites were detected by means of LC-MS/MS analysis. Among them, 18 phenolic acids, 23 flavonoids, and 8 anthocyanins were differentially accumulated in the strawberry fruits irradiated with red/blue (RB) light compared to 30 phenolic acids, 46 flavonoids, and 9 anthocyanins in fruits irradiated with UVB. The major genes associated with the biosynthesis of flavonoids and anthocyanins, including structural genes and transcription factors (TFs), were differentially expressed in the strawberry fruits under RB and UVB irradiation, as determined through RNA-seq data analysis. A correlation test of transcriptome and metabolite profiling showed that the expression patterns of most genes in the biosynthesis pathway of flavonoids and anthocyanins were closely correlated with the differential accumulation of flavonoids and anthocyanins. Two TFs, bZIP (FvH4_2g36400) and AP2 (FvH4_1g21210), induced by RB and UVB irradiation, respectively, exhibited similar expression patterns to most structural genes, which were closely correlated with six and eight flavonoids, respectively. These results indicated that these two TFs regulated the biosynthesis of flavonoids and anthocyanins in strawberry fruit under RB light and UVB, respectively. These results provide a systematic and comprehensive understanding of the accumulation of flavonoids and anthocyanins and the molecular basis for their biosynthesis in strawberry fruits under RB light and UVB. Full article

(This article belongs to the Special Issue Horticultural Plant Cultivation and Fruit Quality Enhancement)

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15 pages, 4753 KiB

Open AccessEditor’s ChoiceArticle

Variation in Water-Holding Capacity in Sphagnum Species Depends on Both Plant and Colony Structure

by Willem Q. M. van de Koot, James Msonda, Olga P. Olver, John H. Doonan and Candida Nibau

Plants 2024, 13(8), 1061; https://doi.org/10.3390/plants13081061 - 9 Apr 2024

Cited by 8 | Viewed by 3293

Abstract

Peatlands have become a focal point in climate mitigation strategies as these ecosystems have significant carbon sequestration capacities when healthy but release CO₂ and other greenhouse gases when damaged. However, as drought episodes become more frequent and prolonged, organisms key to the [...] Read more.

Peatlands have become a focal point in climate mitigation strategies as these ecosystems have significant carbon sequestration capacities when healthy but release CO₂ and other greenhouse gases when damaged. However, as drought episodes become more frequent and prolonged, organisms key to the functioning of some peatlands are increasingly under pressure from desiccation. The Sphagnum mosses, which tend to keep their ecosystem waterlogged and many of whom promote peat formation, are only mildly desiccation-tolerant in comparison to other mosses. The role of Sphagnum anatomy and colony structure is poorly understood in the context of desiccation resilience. Using four different Sphagnum species belonging to four different subgenera and positions along the gradient of the water table, we show that plant morphological traits and colony density are important determinants of water storage capacity. Our results show that, as previously postulated, the majority of the water is stored in an easily exchangeable form, probably extracellularly, and that plant morphological traits, specifically the type and presence of branches, are major contributors to water storage and can explain some of the interspecies variation. We also show that plant density is another important determinant for water storage capacity as higher densities hold larger quantities of water per unit of biomass for all four species, which increases resilience to desiccation. The results presented here suggest that species choice and planting density should receive more attention when considering peatland restoration strategies. Full article

(This article belongs to the Special Issue Bryophyte Biology)

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15 pages, 2020 KiB

Open AccessEditor’s ChoiceArticle

Comparative Phytoprofiling of Achillea millefolium Morphotypes: Assessing Antioxidant Activity, Phenolic and Triterpenic Compounds Variation across Different Plant Parts

by Lina Raudone, Gabriele Vilkickyte, Mindaugas Marksa and Jolita Radusiene

Plants 2024, 13(7), 1043; https://doi.org/10.3390/plants13071043 - 8 Apr 2024

Cited by 10 | Viewed by 2629

Abstract

Achillea millefolium L., commonly known as yarrow, is a versatile and widely distributed plant species with a rich history of ethnopharmacological significance. This study aimed to evaluate the comparative differences of A. millefolium inflorescence morphotypes. The phytochemical profile of white and pink inflorescence [...] Read more.

Achillea millefolium L., commonly known as yarrow, is a versatile and widely distributed plant species with a rich history of ethnopharmacological significance. This study aimed to evaluate the comparative differences of A. millefolium inflorescence morphotypes. The phytochemical profile of white and pink inflorescence morphotypes was characterised by a complex of thirty-four phenolic and triterpene compounds. The species has distinct morphotypes of white and pink inflorescence. Phenolic and triterpenic profiles were determined, and individual compounds were quantified in inflorescence, leaf, and stem samples of two morphotypes tested. The antioxidant activity of plant extracts was evaluated by free radical scavenging (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Caffeoylquinic acids predominated in all parts of the plant tested. Chlorogenic acid and 3,5-dicaffeoylquinic acid were the principal compounds in the phenolic profile. Betulin, betulinic acid, and α-amyrin were the prevailing triterpenic components in the triterpenic profiles of Achillea millefolium morphotypes. The predominant flavonoids in inflorescences were flavones, while in leaves, flavonols were the organ-specific compounds. The quantitative differences were observed between plant parts of morphotypes. Leaves consistently displayed the highest amounts of identified compounds and have been testified as the main source of antioxidant activity. Overall, white inflorescences accumulated a higher total amount of compounds compared to pink ones. The observed differences between morphotypes derived from the same population reflect the differences in specialised metabolites and their chemotypes. This study addresses gaps in knowledge, particularly in phenolic and triterpenic profiling of coloured inflorescence morphotypes, enhancing our understanding of chemotypes and morphotypes within the species. Full article

(This article belongs to the Special Issue Wild Aromatic and Medicinal Plants: Ethnobotany, Biochemistry, and Potential Applications)

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16 pages, 7780 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Identification of NAC Family Genes in Oat and Functional Characterization of AsNAC109 in Abiotic Stress Tolerance

by Yahui Xu, Jialong Cheng, Haibin Hu, Lin Yan, Juqing Jia and Bin Wu

Plants 2024, 13(7), 1017; https://doi.org/10.3390/plants13071017 - 3 Apr 2024

Cited by 8 | Viewed by 1970

Abstract

The plant-specific NAC gene family is one of the largest transcription factor families, participating in plant growth regulation and stress response. Despite extensive characterization in various plants, our knowledge of the NAC family in oat is lacking. Herein, we identified 333 NAC genes [...] Read more.

The plant-specific NAC gene family is one of the largest transcription factor families, participating in plant growth regulation and stress response. Despite extensive characterization in various plants, our knowledge of the NAC family in oat is lacking. Herein, we identified 333 NAC genes from the latest release of the common oat genome. We provide a comprehensive overview of the oat NAC gene family, covering gene structure, chromosomal localization, phylogenetic characteristics, conserved motif compositions, and gene duplications. AsNAC gene expression in different tissues and the response to various abiotic stresses were characterized using RT-qPCR. The main driver of oat NAC gene family expansion was identified as segmental duplication using collinearity analysis. In addition, the functions of AsNAC109 in regulating abiotic stress tolerance in Arabidopsis were clarified. This is the first genome-wide investigation of the NAC gene family in cultivated oat, which provided a unique resource for subsequent research to elucidate the mechanisms responsible for oat stress tolerance and provides valuable clues for the improvement of stress resistance in cultivated oat. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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19 pages, 1592 KiB

Open AccessEditor’s ChoiceArticle

Antidiabetic Properties of the Root Extracts of Dandelion (Taraxacum officinale) and Burdock (Arctium lappa)

by Daria Zolotova, Renāte Teterovska, Dace Bandere, Liga Lauberte and Santa Niedra

Plants 2024, 13(7), 1021; https://doi.org/10.3390/plants13071021 - 3 Apr 2024

Cited by 6 | Viewed by 4626

Abstract

Several preclinical studies suggest the potential of edible plants in controlling blood sugar levels and stabilizing diet. The goals of the study were to examine, analyze, and describe whether there are chemical compounds in dandelion and burdock roots that could have antidiabetic properties. [...] Read more.

Several preclinical studies suggest the potential of edible plants in controlling blood sugar levels and stabilizing diet. The goals of the study were to examine, analyze, and describe whether there are chemical compounds in dandelion and burdock roots that could have antidiabetic properties. The 70% ethyl alcohol and lyophilizate extracts (AE and LE, respectively), were used, and analyses were carried out on their total polysaccharide (TP), total phenolic content (TPC), tannin, and inulin. The antioxidant activity of extracts was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, and hypoglycemic properties were based on α-amylase activity. Liquid chromatography–mass spectrometry was used for the tentative identification of the chemical components. Qualitative techniques confirmed the presence of inulin in both roots. Analysis of TPC, tannin content, DPPH assay, and α-amylase activity revealed higher values for burdock compared to dandelion. However, dandelion exhibited higher TP content. Burdock contained a small amount of tannin, whereas the tannin content in dandelion was insignificant. All LE consistently exhibited higher values in all analyses and assays for all roots compared to AE. Despite burdock root showing overall better results, it is uncertain whether these plants can be recommended as antidiabetic agents without in vivo studies. Full article

(This article belongs to the Special Issue Natural Plant Products in Drug Discovery)

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17 pages, 2886 KiB

Open AccessEditor’s ChoiceArticle

Changes in Photosystem II Complex and Physiological Activities in Pea and Maize Plants in Response to Salt Stress

by Martin A. Stefanov, Georgi D. Rashkov, Preslava B. Borisova and Emilia L. Apostolova

Plants 2024, 13(7), 1025; https://doi.org/10.3390/plants13071025 - 3 Apr 2024

Cited by 10 | Viewed by 2324

Abstract

Salt stress significantly impacts the functions of the photosynthetic apparatus, with varying degrees of damage to its components. Photosystem II (PSII) is more sensitive to environmental stresses, including salinity, than photosystem I (PSI). This study investigated the effects of different salinity levels (0 [...] Read more.

Salt stress significantly impacts the functions of the photosynthetic apparatus, with varying degrees of damage to its components. Photosystem II (PSII) is more sensitive to environmental stresses, including salinity, than photosystem I (PSI). This study investigated the effects of different salinity levels (0 to 200 mM NaCl) on the PSII complex in isolated thylakoid membranes from hydroponically grown pea (Pisum sativum L.) and maize (Zea mays L.) plants treated with NaCl for 5 days. The data revealed that salt stress inhibits the photochemical activity of PSII (H₂O → BQ), affecting the energy transfer between the pigment–protein complexes of PSII (as indicated by the fluorescence emission ratio F₆₉₅/F₆₈₅), Q_A reoxidation, and the function of the oxygen-evolving complex (OEC). These processes were more significantly affected in pea than in maize under salinity. Analysis of the oxygen evolution curves after flashes and continuous illumination showed a stronger influence on the PSIIα than PSIIβ centers. The inhibition of oxygen evolution was associated with an increase in misses (α), double hits (β), and blocked centers (S_B) and a decrease in the rate constant of turnover of PSII reaction centers (K_D). Salinity had different effects on the two pathways of Q_A reoxidation in maize and pea. In maize, the electron flow from Q_A- to plastoquinone was dominant after treatment with higher NaCl concentrations (150 mM and 200 mM), while in pea, the electron recombination on Q_AQ_B- with oxidized S₂ (or S₃) of the OEC was more pronounced. Analysis of the 77 K fluorescence emission spectra revealed changes in the ratio of the light-harvesting complex of PSII (LHCII) monomers and trimers to LHCII aggregates after salt treatment. There was also a decrease in pigment composition and an increase in oxidative stress markers, membrane injury index, antioxidant activity (FRAP assay), and antiradical activity (DPPH assay). These effects were more pronounced in pea than in maize after treatment with higher NaCl concentrations (150 mM–200 mM). This study provides insights into how salinity influences the processes in the donor and acceptor sides of PSII in plants with different salt sensitivity. Full article

(This article belongs to the Special Issue The Environmental Stress Physiology of Plants)

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16 pages, 23675 KiB

Open AccessEditor’s ChoiceArticle

Comparative Morpho-Physiological, Biochemical, and Gene Expressional Analyses Uncover Mechanisms of Waterlogging Tolerance in Two Soybean Introgression Lines

by Ripa Akter Sharmin, Benjamin Karikari, Mashiur Rahman Bhuiyan, Keke Kong, Zheping Yu, Chunting Zhang and Tuanjie Zhao

Plants 2024, 13(7), 1011; https://doi.org/10.3390/plants13071011 - 2 Apr 2024

Cited by 6 | Viewed by 2682

Abstract

Waterlogging is one of the key abiotic factors that severely impedes the growth and productivity of soybeans on a global scale. To develop soybean cultivars that are tolerant to waterlogging, it is a prerequisite to unravel the mechanisms governing soybean responses to waterlogging. [...] Read more.

Waterlogging is one of the key abiotic factors that severely impedes the growth and productivity of soybeans on a global scale. To develop soybean cultivars that are tolerant to waterlogging, it is a prerequisite to unravel the mechanisms governing soybean responses to waterlogging. Hence, we explored the morphological, physiological, biochemical, and transcriptional changes in two contrasting soybean introgression lines, A192 (waterlogging tolerant, WT) and A186 (waterlogging sensitive, WS), under waterlogging. In comparison to the WT line, waterlogging drastically decreased the root length (RL), shoot length (ShL), root fresh weight (RFW), shoot fresh weight (ShFW), root dry weight (RDW), and shoot dry weight (ShDW) of the WS line. Similarly, waterlogging inhibited soybean plant growth by suppressing the plant’s photosynthetic capacity, enhancing oxidative damage from reactive oxygen species, and decreasing the chlorophyll content in the WS line but not in the WT line. To counteract the oxidative damage and lipid peroxidation, the WT line exhibited increased activity of antioxidant enzymes such as peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), as well as higher levels of proline content than the WS line. In addition, the expression of antioxidant enzyme genes (POD1, POD2, FeSOD, Cu/ZnSOD, CAT1, and CAT2) and ethylene-related genes (such as ACO1, ACO2, ACS1, and ACS2) were found to be up-regulated in WT line under waterlogging stress conditions. In contrast, these genes showed a down-regulation in their expression levels in the stressed WS line. The integration of morpho-physiological, biochemical, and gene expression analyses provide a comprehensive understanding of the responses of WT and WS lines to waterlogging conditions. These findings would be beneficial for the future development of soybean cultivars that can withstand waterlogging. Full article

(This article belongs to the Special Issue Physiological and Genetic Mechanisms of Abiotic Stress Tolerance in Crops II)

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16 pages, 345 KiB

Open AccessEditor’s ChoiceArticle

High-Value Compounds in Papaya By-Products (Carica papaya L. var. Formosa and Aliança): Potential Sustainable Use and Exploitation

by Ana F. Vinha, Anabela S. G. Costa, Liliana Espírito Santo, Diana M. Ferreira, Carla Sousa, Edgar Pinto, Agostinho Almeida and Maria Beatriz P. P. Oliveira

Plants 2024, 13(7), 1009; https://doi.org/10.3390/plants13071009 - 1 Apr 2024

Cited by 9 | Viewed by 5823

Abstract

Background: Food waste is a global and growing problem that is gaining traction due to its environmental, ethical, social, and economic repercussions. Between 2022 and 2027, the worldwide papaya market is expected to have a huge increase, meaning a growth in organic waste, [...] Read more.

Background: Food waste is a global and growing problem that is gaining traction due to its environmental, ethical, social, and economic repercussions. Between 2022 and 2027, the worldwide papaya market is expected to have a huge increase, meaning a growth in organic waste, including peels and seeds. Thus, this study evaluated the potential use of peels and seeds of two mature papaya fruits as a source of bioactive compounds, converting these by-products into value-added products. Proximate analysis (AOAC methods), mineral content (ICP-MS), free sugars (HPLC-ELSD), fatty acid composition (GC-FID), vitamin E profile (HPLC-DAD-FLD), and antioxidant activity (DPPH and FRAP assays) were evaluated. Results: Both by-products showed high total protein (20–27%), and dietary fiber (32–38%) contents. Papaya peels presented a high ash content (14–16%), indicating a potential application as a mineral source. 14 fatty acids were detected, with α-linolenic acid (30%) as the most abundant in the peels and oleic acid (74%) in the seeds. Both by-products showed high antioxidant activity. Conclusion: Papaya by-products display great potential for industrial recovery and application, such as formulation of new functional food ingredients. Full article

(This article belongs to the Special Issue Chemistry of Plant Natural Products)

29 pages, 7901 KiB

Open AccessEditor’s ChoiceArticle

Origin and Early Evolution of Hydrocharitaceae and the Ancestral Role of Stratiotes

by Silvia Ulrich, Manuel Vieira, Mario Coiro, Johannes M. Bouchal, Christian Geier, Bonnie F. Jacobs, Ellen D. Currano, Olaf K. Lenz, Volker Wilde, Reinhard Zetter and Friðgeir Grímsson

Plants 2024, 13(7), 1008; https://doi.org/10.3390/plants13071008 - 31 Mar 2024

Cited by 5 | Viewed by 2658

Abstract

The combined morphological features of Stratiotes (Hydrocharitaceae) pollen, observed with light and electron microscopy, make it unique among all angiosperm pollen types and easy to identify. Unfortunately, the plant is (and most likely was) insect-pollinated and produces relatively few pollen grains per flower, [...] Read more.

The combined morphological features of Stratiotes (Hydrocharitaceae) pollen, observed with light and electron microscopy, make it unique among all angiosperm pollen types and easy to identify. Unfortunately, the plant is (and most likely was) insect-pollinated and produces relatively few pollen grains per flower, contributing to its apparent absence in the paleopalynological record. Here, we present fossil Stratiotes pollen from the Eocene of Germany (Europe) and Kenya (Africa), representing the first reliable pre-Pleistocene pollen records of this genus worldwide and the only fossils of this family discovered so far in Africa. The fossil Stratiotes pollen grains are described and compared to pollen from a single modern species, Stratiotes aloides L. The paleophytogeographic significance and paleoecological aspects of these findings are discussed in relation to the Hydrocharitaceae fossil records and molecular phylogeny, as well as the present-day distribution patterns of its modern genera. Full article

(This article belongs to the Special Issue Evolution of Land Plants)

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19 pages, 3274 KiB

Open AccessEditor’s ChoiceArticle

N₂ Fixation, N Transfer, and Land Equivalent Ratio (LER) in Grain Legume–Wheat Intercropping: Impact of N Supply and Plant Density

by Sebastian Salinas-Roco, Amanda Morales-González, Soledad Espinoza, Ricardo Pérez-Díaz, Basilio Carrasco, Alejandro del Pozo and Ricardo A. Cabeza

Plants 2024, 13(7), 991; https://doi.org/10.3390/plants13070991 - 30 Mar 2024

Cited by 12 | Viewed by 5641

Abstract

Intercropping legumes with cereals can lead to increased overall yield and optimize the utilization of resources such as water and nutrients, thus enhancing agricultural efficiency. Legumes possess the unique ability to acquire nitrogen (N) through both N₂ fixation and from the available [...] Read more.

Intercropping legumes with cereals can lead to increased overall yield and optimize the utilization of resources such as water and nutrients, thus enhancing agricultural efficiency. Legumes possess the unique ability to acquire nitrogen (N) through both N₂ fixation and from the available N in the soil. However, soil N can diminish the N₂ fixation capacity of legumes. It is postulated that in intercropping, legumes uptake N mainly through N₂ fixation, leaving more soil N available for cereals. The latter, in turn, has larger root systems, allowing it to explore greater soil volume and absorb more N, mitigating its adverse effects on N₂ fixation in legumes. The goal of this study was to evaluate how the supply of N affects the intercropping of faba beans (Vicia faba L.) and peas (Pisum sativum L.) with wheat under varying plant densities and N levels. We measured photosynthetic traits, biomass production, the proportion of N derived from air (%Ndfa) in the shoot of the legumes, the N transferred to the wheat, and the land equivalent ratio (LER). The results revealed a positive correlation between soil N levels and the CO₂ assimilation rate (An), chlorophyll content, and N balance index (NBI) in wheat. However, no significant effect was observed in legumes as soil N levels increased. Transpiration (E) increased in wheat intercropped with legumes, while stomatal conductance (g_s) increased with N addition in all crops. Water use efficiency (WUE) decreased in faba beans intercropped with wheat as N increased, but it showed no significant change in wheat or peas. The shoot dry matter of wheat increased with the addition of N; however, the two legume species showed no significant changes. N addition reduced the %Ndfa of both legume species, especially in monoculture, with peas being more sensitive than faba beans. The intercropping of wheat alleviated N₂ fixation inhibition, especially at high wheat density and increased N transfer to wheat, particularly with peas. The LER was higher in the intercropping treatments, especially under limited N conditions. It is concluded that in the intercropping of wheat with legumes, the N₂ fixation inhibition caused by soil N is effectively reduced, as well as there being a significant N transfer from the legume to the wheat, with both process contributing to increase LER. Full article

(This article belongs to the Special Issue Strategies for Nutrient Use Efficiency Improvement in Plants)

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22 pages, 4671 KiB

Open AccessEditor’s ChoiceReview

The Impact of Nanomaterials on Photosynthesis and Antioxidant Mechanisms in Gramineae Plants: Research Progress and Future Prospects

by Ping Li, Yunfei Xia, Kai Song and Duo Liu

Plants 2024, 13(7), 984; https://doi.org/10.3390/plants13070984 - 29 Mar 2024

Cited by 22 | Viewed by 3971

Abstract

As global food security faces challenges, enhancing crop yield and stress resistance becomes imperative. This study comprehensively explores the impact of nanomaterials (NMs) on Gramineae plants, with a focus on the effects of various types of nanoparticles, such as iron-based, titanium-containing, zinc, and [...] Read more.

As global food security faces challenges, enhancing crop yield and stress resistance becomes imperative. This study comprehensively explores the impact of nanomaterials (NMs) on Gramineae plants, with a focus on the effects of various types of nanoparticles, such as iron-based, titanium-containing, zinc, and copper nanoparticles, on plant photosynthesis, chlorophyll content, and antioxidant enzyme activity. We found that the effects of nanoparticles largely depend on their chemical properties, particle size, concentration, and the species and developmental stage of the plant. Under appropriate conditions, specific NMs can promote the root development of Gramineae plants, enhance photosynthesis, and increase chlorophyll content. Notably, iron-based and titanium-containing nanoparticles show significant effects in promoting chlorophyll synthesis and plant growth. However, the impact of nanoparticles on oxidative stress is complex. Under certain conditions, nanoparticles can enhance plants’ antioxidant enzyme activity, improving their ability to withstand environmental stresses; excessive or inappropriate NMs may cause oxidative stress, affecting plant growth and development. Copper nanoparticles, in particular, exhibit this dual nature, being beneficial at low concentrations but potentially harmful at high concentrations. This study provides a theoretical basis for the future development of nanofertilizers aimed at precisely targeting Gramineae plants to enhance their antioxidant stress capacity and improve photosynthesis efficiency. We emphasize the importance of balancing the agricultural advantages of nanotechnology with environmental safety in practical applications. Future research should focus on a deeper understanding of the interaction mechanisms between more NMs and plants and explore strategies to reduce potential environmental impacts to ensure the health and sustainability of the ecosystem while enhancing the yield and quality of Gramineae crops. Full article

(This article belongs to the Special Issue The Impact of Nanomaterials on Plant Growth, Development and Metabolism (Volume II))

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27 pages, 7676 KiB

Open AccessEditor’s ChoiceArticle

Application of Multimodal Transformer Model in Intelligent Agricultural Disease Detection and Question-Answering Systems

by Yuchun Lu, Xiaoyi Lu, Liping Zheng, Min Sun, Siyu Chen, Baiyan Chen, Tong Wang, Jiming Yang and Chunli Lv

Plants 2024, 13(7), 972; https://doi.org/10.3390/plants13070972 - 28 Mar 2024

Cited by 17 | Viewed by 4897

Abstract

In this study, an innovative approach based on multimodal data and the transformer model was proposed to address challenges in agricultural disease detection and question-answering systems. This method effectively integrates image, text, and sensor data, utilizing deep learning technologies to profoundly analyze and [...] Read more.

In this study, an innovative approach based on multimodal data and the transformer model was proposed to address challenges in agricultural disease detection and question-answering systems. This method effectively integrates image, text, and sensor data, utilizing deep learning technologies to profoundly analyze and process complex agriculture-related issues. The study achieved technical breakthroughs and provides new perspectives and tools for the development of intelligent agriculture. In the task of agricultural disease detection, the proposed method demonstrated outstanding performance, achieving a precision, recall, and accuracy of 0.95, 0.92, and 0.94, respectively, significantly outperforming the other conventional deep learning models. These results indicate the method’s effectiveness in identifying and accurately classifying various agricultural diseases, particularly excelling in handling subtle features and complex data. In the task of generating descriptive text from agricultural images, the method also exhibited impressive performance, with a precision, recall, and accuracy of 0.92, 0.88, and 0.91, respectively. This demonstrates that the method can not only deeply understand the content of agricultural images but also generate accurate and rich descriptive texts. The object detection experiment further validated the effectiveness of our approach, where the method achieved a precision, recall, and accuracy of 0.96, 0.91, and 0.94. This achievement highlights the method’s capability for accurately locating and identifying agricultural targets, especially in complex environments. Overall, the approach in this study not only demonstrated exceptional performance in multiple tasks such as agricultural disease detection, image captioning, and object detection but also showcased the immense potential of multimodal data and deep learning technologies in the application of intelligent agriculture. Full article

(This article belongs to the Special Issue The Future of Artificial Intelligence and Sensor Systems in Agriculture)

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18 pages, 4087 KiB

Open AccessEditor’s ChoiceArticle

Alfalfa Responses to Intensive Soil Compaction: Effects on Plant and Root Growth, Phytohormones and Internal Gene Expression

by Mingke Yan, Dongming Yang, Yijun He, Yonglong Ma, Xin Zhang, Quanzhen Wang and Jinghui Gao

Plants 2024, 13(7), 953; https://doi.org/10.3390/plants13070953 - 26 Mar 2024

Cited by 5 | Viewed by 2924

Abstract

The perennial legume alfalfa (Medicago sativa L.) is of high value in providing cheap and high-nutritive forages. Due to a lack of tillage during the production period, the soil in which alfalfa grows prunes to become compacted through highly mechanized agriculture. Compaction [...] Read more.

The perennial legume alfalfa (Medicago sativa L.) is of high value in providing cheap and high-nutritive forages. Due to a lack of tillage during the production period, the soil in which alfalfa grows prunes to become compacted through highly mechanized agriculture. Compaction deteriorates the soil’s structure and fertility, leading to compromised alfalfa development and productivity. However, the way alfalfa responses to different levels of soil compaction and the underlying molecular mechanism are still unclear. In this study, we systematically evaluated the effects of gradient compacted soil on the growth of different cultivars of alfalfa, especially the root system architecture, phytohormones and internal gene expression profile alterations. The results showed that alfalfa growth was facilitated by moderate soil compaction, but drastically inhibited when compaction was intensified. The inhibition effect was universal across different cultivars, but with different severity. Transcriptomic and physiological studies revealed that the expression of a set of genes regulating the biosynthesis of lignin and flavonoids was significantly repressed in compaction treated alfalfa roots, and this might have resulted in a modified secondary cell wall and xylem vessel formation. Phytohormones, like ABA, are supposed to play pivotal roles in the regulation of the overall responses. These findings provide directions for the improvement of field soil management in alfalfa production and the molecular breeding of alfalfa germplasm with better soil compaction resilience. Full article

(This article belongs to the Topic Sustainable Crop Production from Problematic Soils to Ensure Food Security)

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17 pages, 3940 KiB

Open AccessEditor’s ChoiceArticle

Diversity of the Maize Root Endosphere and Rhizosphere Microbiomes Modulated by the Inoculation with Pseudomonas fluorescens UM270 in a Milpa System

by Blanca Rojas-Sánchez, Hugo Castelán-Sánchez, Esmeralda Y. Garfias-Zamora and Gustavo Santoyo

Plants 2024, 13(7), 954; https://doi.org/10.3390/plants13070954 - 26 Mar 2024

Cited by 6 | Viewed by 2947

Abstract

Milpa is an agroecological production system based on the polyculture of plant species, with corn featuring as a central component. Traditionally, the milpa system does not require the application of chemicals, and so pest attacks and poor growth in poor soils can have [...] Read more.

Milpa is an agroecological production system based on the polyculture of plant species, with corn featuring as a central component. Traditionally, the milpa system does not require the application of chemicals, and so pest attacks and poor growth in poor soils can have adverse effects on its production. Therefore, the application of bioinoculants could be a strategy for improving crop growth and health; however, the effect of external inoculant agents on the endemic microbiota associated with corn has not been extensively studied. Here, the objective of this work was to fertilize a maize crop under a milpa agrosystem with the PGPR Pseudomonas fluorescens UM270, evaluating its impact on the diversity of the rhizosphere (rhizobiome) and root endophytic (root endobiome) microbiomes of maize plants. The endobiome of maize roots was evaluated by 16S rRNA and internal transcribed spacer region (ITS) sequencing, and the rhizobiome was assessed by metagenomic sequencing upon inoculation with the strain UM270. The results showed that UM270 inoculation of the rhizosphere of P. fluorescens UM270 did not increase alpha diversity in either the monoculture or milpa, but it did alter the endophytic microbiome of maize plant roots by stimulating the presence of bacterial operational taxonomic units (OTUs) of the genera Burkholderia and Pseudomonas (in a monoculture), whereas, in the milpa system, the PGPR stimulated greater endophytic diversity and the presence of genera such as Burkholderia, Variovorax, and N-fixing rhizobia genera, including Rhizobium, Mesorhizobium, and Bradyrhizobium. No clear association was found between fungal diversity and the presence of strain UM270, but beneficial fungi, such as Rizophagus irregularis and Exophiala pisciphila, were detected in the Milpa system. In addition, network analysis revealed unique interactions with species such as Stenotrophomonas sp., Burkholderia xenovorans, and Sphingobium yanoikuyae, which could potentially play beneficial roles in the plant. Finally, the UM270 strain does not seem to have a strong impact on the microbial diversity of the rhizosphere, but it does have a strong impact on some functions, such as trehalose synthesis, ammonium assimilation, and polyamine metabolism. The inoculation of UM270 biofertilizer in maize plants modifies the rhizo- and endophytic microbiomes with a high potential for stimulating plant growth and health in agroecological crop models. Full article

(This article belongs to the Collection Feature Papers in Plant Protection)

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17 pages, 2559 KiB

Open AccessEditor’s ChoiceArticle

Ozone Treatment as an Approach to Induce Specialized Compounds in Melissa officinalis Plants

by Giulia Scimone, Maria Giovanna Carucci, Samuele Risoli, Claudia Pisuttu, Lorenzo Cotrozzi, Giacomo Lorenzini, Cristina Nali, Elisa Pellegrini and Maike Petersen

Plants 2024, 13(7), 933; https://doi.org/10.3390/plants13070933 - 23 Mar 2024

Cited by 8 | Viewed by 1737

Abstract

Plants are constantly subjected to environmental changes that deeply affect their metabolism, leading to the inhibition or synthesis of “specialized” compounds, small organic molecules that play a fundamental role in adaptative responses. In this work, Melissa officinalis L. (an aromatic plant broadly cultivated [...] Read more.

Plants are constantly subjected to environmental changes that deeply affect their metabolism, leading to the inhibition or synthesis of “specialized” compounds, small organic molecules that play a fundamental role in adaptative responses. In this work, Melissa officinalis L. (an aromatic plant broadly cultivated due to the large amounts of secondary metabolites) plants were exposed to realistic ozone (O₃) dosages (80 ppb, 5 h day⁻¹) for 35 consecutive days with the aim to evaluate its potential use as elicitor of specialized metabolite production. Ozone induced stomatal dysfunction throughout the whole experiment, associated with a low photosynthetic performance, a decrease in the potential energy conversion activity of PSII, and an alteration in the total chlorophyll content (−35, −36, −10, and −17% as average compared to the controls, respectively). The production of hydrogen peroxide at 7 days from the beginning of exposure (+47%) resulted in lipid peroxidation and visible injuries. This result suggests metabolic disturbance within the cell and a concomitant alteration in cell homeostasis, probably due to a limited activation of antioxidative mechanisms. Moderate accumulated doses of O₃ triggered the accumulation of hydroxycinnamic acids and the up-regulation of the genes encoding enzymes involved in rosmarinic acid, phenylpropanoid, and flavonoid biosynthesis. While high accumulated doses of O₃ significantly enhanced the content of hydroxybenzoic acid and flavanone glycosides. Our study shows that the application of O₃ at the investigated concentration for a limited period (such as two/three weeks) may become a useful tool to stimulate bioactive compounds production in M. officinalis. Full article

(This article belongs to the Special Issue Phytochemical Analyses of Secondary Metabolites of Aromatic, Medicinal and Food Plants)

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47 pages, 2711 KiB

Open AccessEditor’s ChoiceReview

Impact of Heavy Metal Pollution in the Environment on the Metabolic Profile of Medicinal Plants and Their Therapeutic Potential

by Dana-Mihaela Asiminicesei, Daniela Ionela Fertu and Maria Gavrilescu

Plants 2024, 13(6), 913; https://doi.org/10.3390/plants13060913 - 21 Mar 2024

Cited by 36 | Viewed by 7864

Abstract

The paper provides a comprehensive examination of heavy metal stress on medicinal plants, focusing on its impact on antioxidant capacity and biosynthetic pathways critical to their therapeutic potential. It explores the complex relationship between heavy metals and the physiological and biochemical responses of [...] Read more.

The paper provides a comprehensive examination of heavy metal stress on medicinal plants, focusing on its impact on antioxidant capacity and biosynthetic pathways critical to their therapeutic potential. It explores the complex relationship between heavy metals and the physiological and biochemical responses of medicinal plants, highlighting how metal stress disrupts biosynthetic pathways, altering concentrations of secondary metabolites. This disruption may compromise the overall quality and efficacy of medicinal plants, requiring a holistic understanding of its cumulative impacts. Furthermore, the study discusses the potential of targeted genetic editing to enhance plant resilience against heavy metal stress by manipulating genes associated with antioxidant defenses. This approach represents a promising frontier in safeguarding medicinal plants in metal-contaminated environments. Additionally, the research investigates the role of phytohormone signaling in plant adaptive mechanisms to heavy metal stress, revealing its influence on biochemical and physiological responses, thereby adding complexity to plant adaptation. The study underscores the importance of innovative technologies and global cooperation in protecting medicinal plants’ therapeutic potential and highlights the need for mitigation strategies to address heavy metal contamination effectively. Full article

(This article belongs to the Special Issue Metal/Metalloid Toxicity in Plants: Rhizosphere Mycorrhizal and Microbial Strategies for Stress Management and Remediation)

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16 pages, 5818 KiB

Open AccessEditor’s ChoiceArticle

Distribution Pattern of Suitable Areas and Corridor Identification of Endangered Ephedra Species in China

by Huayong Zhang, Jiangpeng Li, Hengchao Zou, Zhongyu Wang, Xinyu Zhu, Yihe Zhang and Zhao Liu

Plants 2024, 13(6), 890; https://doi.org/10.3390/plants13060890 - 20 Mar 2024

Cited by 8 | Viewed by 2099

Abstract

The suitable habitat of endangered Ephedra species has been severely threatened and affected by climate change and anthropogenic activities; however, their migration trends and restoration strategies are still relatively understudied. In this study, we utilized the MaxEnt model to simulate the suitable habitats [...] Read more.

The suitable habitat of endangered Ephedra species has been severely threatened and affected by climate change and anthropogenic activities; however, their migration trends and restoration strategies are still relatively understudied. In this study, we utilized the MaxEnt model to simulate the suitable habitats of five endangered Ephedra species in China under current and future climate scenarios. Additionally, we identified significant ecological corridors by incorporating the minimum cumulative resistance (MCR) model. Under the current climate scenario, the suitable area of Ephedra equisetina Bunge, Ephedra intermedia Schrenk ex Mey, Ephedra sinica Stapf, and Ephedra monosperma Gmel ex Mey comprised 16% of the area in China, while Ephedra rhytidosperma Pachom comprised only 0.05%. The distribution patterns of these five Ephedra species were primarily influenced by altitude, salinity, temperature, and precipitation. Under future climate scenarios, the suitable areas of E. equisetina, E. intermedia, and E. sinica are projected to expand, while that of E. monosperma is expected to contract. Notably, E. rhytidosperma will lose its suitable area in the future. Our identified ecological corridors showed that the first-level corridors encompassed a wider geographical expanse, incorporating E. equisetina, E. intermedia, E. sinica, and E. monosperma, while that of E. rhytidosperma exhibited a shorter length and covered fewer geographical areas. Overall, our study provides novel insights into identifying priority protected areas and protection strategies targeting endangered Ephedra species. Full article

(This article belongs to the Section Plant Ecology)

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15 pages, 4753 KiB

Open AccessEditor’s ChoiceArticle

Variation in Nutritional Components and Antioxidant Capacity of Different Cultivars and Organs of Basella alba

by Yi Zhang, Wenjuan Cheng, Hongmei Di, Shihan Yang, Yuxiao Tian, Yuantao Tong, Huanhuan Huang, Victor Hugo Escalona, Yi Tang, Huanxiu Li, Fen Zhang, Bo Sun and Zhi Huang

Plants 2024, 13(6), 892; https://doi.org/10.3390/plants13060892 - 20 Mar 2024

Cited by 11 | Viewed by 4180

Abstract

Basella alba is a frequently consumed leafy vegetable. However, research on its nutritional components is limited. This study aimed to explore the variation in the nutritional components and antioxidant capacity of different cultivars and organs of Basella alba. Here, we primarily chose [...] Read more.

Basella alba is a frequently consumed leafy vegetable. However, research on its nutritional components is limited. This study aimed to explore the variation in the nutritional components and antioxidant capacity of different cultivars and organs of Basella alba. Here, we primarily chose classical spectrophotometry and high-performance liquid chromatography (HPLC) to characterize the variation in nutritional components and antioxidant capacity among different organs (inflorescences, green fruits, black fruits, leaves, and stems) of eight typical cultivars of Basella alba. The determination indices (and methods) included the total soluble sugar (anthrone colorimetry), total soluble protein (the Bradford method), total chlorophyll (the ethanol-extracting method), total carotenoids (the ethanol-extracting method), total ascorbic acid (the HPLC method), total proanthocyanidins (the p-dimethylaminocinnamaldehyde method), total flavonoids (AlCl₃ colorimetry), total phenolics (the Folin method), and antioxidant capacity (the FRAP and ABTS methods). The results indicated that M5 and M6 exhibited advantages in their nutrient contents and antioxidant capacities. Additionally, the inflorescences demonstrated the highest total ascorbic acid and total phenolic contents, while the green and black fruits exhibited relatively high levels of total proanthocyanidins and antioxidant capacity. In a comparison between the green and black fruits, the green fruits showed higher levels of total chlorophyll (0.77–1.85 mg g⁻¹ DW), total proanthocyanidins (0.62–2.34 mg g⁻¹ DW), total phenolics (15.28–27.35 mg g⁻¹ DW), and ABTS (43.39–59.16%), while the black fruits exhibited higher levels of total soluble protein (65.45–89.48 mg g⁻¹ DW) and total soluble sugar (56.40–207.62 mg g⁻¹ DW) in most cultivars. Chlorophyll, carotenoids, and flavonoids were predominantly found in the leaves of most cultivars, whereas the total soluble sugar contents were highest in the stems of most cultivars. Overall, our findings underscore the significant influence of the cultivars on the nutritional composition of Basella alba. Moreover, we observed notable variations in the nutrient contents among the different organs of the eight cultivars, and proanthocyanidins may contribute significantly to the antioxidant activity of the fruits. On the whole, this study provides a theoretical basis for the genetic breeding of Basella alba and dietary nutrition and serves as a reference for the comprehensive utilization of this vegetable. Full article

(This article belongs to the Special Issue Molecular and Physiological Regulation of Secondary Metabolism in Vegetables (2nd Edition))

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16 pages, 3166 KiB

Open AccessEditor’s ChoiceArticle

Physiological Regulation of Photosynthetic-Related Indices, Antioxidant Defense, and Proline Anabolism on Drought Tolerance of Wild Soybean (Glycine soja L.)

by Song Lin, Weimei Zhang, Guifeng Wang, Yunxiang Hu, Xuanbo Zhong and Guixiang Tang

Plants 2024, 13(6), 880; https://doi.org/10.3390/plants13060880 - 19 Mar 2024

Cited by 10 | Viewed by 2629

Abstract

Wild soybean (Glycine soja L.), drought-tolerant cultivar Tiefeng 31 (Glycine max L.), and drought-sensitive cultivar Fendou 93 (Glycine max L.) were used as materials to investigate the drought tolerance mechanism after 72 h 2.5 M PEG 8000 (osmotic potential −0.54 [...] Read more.

Wild soybean (Glycine soja L.), drought-tolerant cultivar Tiefeng 31 (Glycine max L.), and drought-sensitive cultivar Fendou 93 (Glycine max L.) were used as materials to investigate the drought tolerance mechanism after 72 h 2.5 M PEG 8000 (osmotic potential −0.54 MPa)-simulated drought stress at the seedling stage. The results indicated that the leaves of the G. soja did not wilt under drought stress. However, both the drought-tolerant and drought-sensitive cultivated soybean cultivars experienced varying degrees of leaf wilt. Notably, the drought-sensitive cultivated soybean cultivars exhibited severe leaf wilt after the drought stress. Drought stress was determined to have a significant impact on the dry matter of the above-ground part of the drought-sensitive cultivar Fendou 93, followed by the drought-tolerant cultivar Tiefeng 31, with the lowest reduction observed in G. soja. Furthermore, the presence of drought stress resulted in the closure of leaf stomata. G. soja exhibited the highest proportion of stomatal opening per unit area, followed by the drought-tolerant cultivar Tiefeng 31, while the drought-sensitive cultivar Fendou 93 displayed the lowest percentage. Photosynthesis-related indexes, including photosynthetic rate, intercellular CO₂, transpiration rate, and stomatal conductance, decreased in Fendou 93 and Tiefeng 31 after drought stress, but increased in G. soja. In terms of the antioxidant scavenging system, lower accumulation of malondialdehyde (MDA) was observed in G. soja and Tiefeng 31, along with higher activities of superoxide dismutase (SOD, EC 1.15.1.1) and catalase (CAT, EC 1.11.1.6) to counteract excess reactive oxygen species and maintain cell membrane integrity. In contrast, the drought-sensitive cultivar Fendou 93 had higher MDA content and higher activities of ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POD, 1.11.1.7). G. soja and Tiefeng 31 also exhibited less accumulation of osmolytes, including soluble sugar, soluble protein, and free proline content. The activities of δ-OAT, ProDH, and P5CS, key enzymes in proline anabolism, showed an initial increase under drought stress, followed by a decrease, and then an increase again at the end of drought stress in G. soja. Before drought stress, Tiefeng 31 had higher activities of ProDH and P5CS, which decreased with prolonged drought stress. Fendou 93 experienced an increase in the activities of δ-OAT, ProDH, and P5CS under drought stress. The δ-OAT gene expression levels were up-regulated in all three germplasms. The expression levels of the P5CS gene in Fendou 93 and Tiefeng 31 were down-regulated, while G. soja showed no significant change. The expression of the P5CR gene and ProDH gene was down-regulated in Fendou 93 and Tiefeng 31, but up-regulated in G. soja. This indicates that proline content is regulated at both the transcription and translation levels. Full article

(This article belongs to the Special Issue Advances in Legume Crops Research)

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13 pages, 4606 KiB

Open AccessEditor’s ChoiceArticle

Insights into Reactive Oxygen Species Production-Scavenging System Involved in Sugarcane Response to Xanthomonas albilineans Infection under Drought Stress

by Yao-Sheng Wei, Jian-Ying Zhao, Talha Javed, Ahmad Ali, Mei-Ting Huang, Hua-Ying Fu, Hui-Li Zhang and San-Ji Gao

Plants 2024, 13(6), 862; https://doi.org/10.3390/plants13060862 - 17 Mar 2024

Cited by 4 | Viewed by 1719

Abstract

Plants must adapt to the complex effects of several stressors brought on by global warming, which may result in interaction and superposition effects between diverse stressors. Few reports are available on how drought stress affects Xanthomonas albilineans (Xa) infection in sugarcane [...] Read more.

Plants must adapt to the complex effects of several stressors brought on by global warming, which may result in interaction and superposition effects between diverse stressors. Few reports are available on how drought stress affects Xanthomonas albilineans (Xa) infection in sugarcane (Saccharum spp. hybrids). Drought and leaf scald resistance were identified on 16 sugarcane cultivars using Xa inoculation and soil drought treatments, respectively. Subsequently, four cultivars contrasting to drought and leaf scald resistance were used to explore the mechanisms of drought affecting Xa–sugarcane interaction. Drought stress significantly increased the occurrence of leaf scald and Xa populations in susceptible cultivars but had no obvious effect on resistant cultivars. The ROS bursting and scavenging system was significantly activated in sugarcane in the process of Xa infection, particularly in the resistant cultivars. Compared with Xa infection alone, defense response via the ROS generating and scavenging system was obviously weakened in sugarcane (especially in susceptible cultivars) under Xa infection plus drought stress. Collectively, ROS might play a crucial role involving sugarcane defense against combined effects of Xa infection and drought stress. Full article

(This article belongs to the Special Issue Interaction between Sugarcane and Environmental Stressors: From Identification to Molecular Mechanism)

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19 pages, 1622 KiB

Open AccessEditor’s ChoiceReview

A Critical Review of Methodologies for Evaluating Iron Fertilizers Based on Iron Reduction and Uptake by Strategy I Plants

by Alejandra Arcas, Sandra López-Rayo, Agustín Gárate and Juan J. Lucena

Plants 2024, 13(6), 819; https://doi.org/10.3390/plants13060819 - 13 Mar 2024

Cited by 4 | Viewed by 2831

Abstract

Under iron (Fe)-limited conditions, plants have developed strategies for acquiring this essential micronutrient. Several Fe sources have been studied as potential fertilizers, with Fe synthetic chelates being the most used to prevent and correct Fe chlorosis in crops. The determination of the activity [...] Read more.

Under iron (Fe)-limited conditions, plants have developed strategies for acquiring this essential micronutrient. Several Fe sources have been studied as potential fertilizers, with Fe synthetic chelates being the most used to prevent and correct Fe chlorosis in crops. The determination of the activity of the Fe chelate reductase (FCR) enzyme has long been described in the literature to understand the efficiency of Strategy I plants in acquiring Fe from fertilizers under deficient conditions. Other experiments have focused on the translocation of Fe to the plant to define the effectiveness of Fe fertilizers. Yet, both assays are relevant in knowing the capacity of a novel Fe source and other compounds alleviating Fe chlorosis in Strategy I plants. This work reviews the methodologies that are used in FCR assays to evaluate novel Fe fertilizers, including the factors modulating the results obtained for FCR assay activity, such as the Fe substrate, the Fe level during the growing period and during the FCR assay, the pH, the choice of an in vivo or in vitro method, and the plant species. A discussion of the benefits of the concurrence of FCR and Fe uptake assays is then presented alongside a proposed methodology for assessing the effectiveness of Fe fertilizers, emphasizing the importance of understanding chemical and physiological plant interactions. This methodology unifies key factors that modify FCR activity and combines these with the use of the ⁵⁷Fe tracer to enhance our comprehension of the efficacy of Fe-based fertilizers’ effectiveness in alleviating Fe chlorosis. This comprehensive approach not only contributes to the fundamental understanding of Fe-deficient Strategy I plants but also establishes a robust method for determining the efficiency of novel sources for correcting Fe deficiency in plants. Full article

(This article belongs to the Special Issue In Memory of Professor Javier Abadía, a World Leader in Plant Stress Physiology)

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23 pages, 1712 KiB

Open AccessEditor’s ChoiceReview

Exchange or Eliminate: The Secrets of Algal-Bacterial Relationships

by Bertille Burgunter-Delamare, Prateek Shetty, Trang Vuong and Maria Mittag

Plants 2024, 13(6), 829; https://doi.org/10.3390/plants13060829 - 13 Mar 2024

Cited by 9 | Viewed by 4617

Abstract

Algae and bacteria have co-occurred and coevolved in common habitats for hundreds of millions of years, fostering specific associations and interactions such as mutualism or antagonism. These interactions are shaped through exchanges of primary and secondary metabolites provided by one of the partners. [...] Read more.

Algae and bacteria have co-occurred and coevolved in common habitats for hundreds of millions of years, fostering specific associations and interactions such as mutualism or antagonism. These interactions are shaped through exchanges of primary and secondary metabolites provided by one of the partners. Metabolites, such as N-sources or vitamins, can be beneficial to the partner and they may be assimilated through chemotaxis towards the partner producing these metabolites. Other metabolites, especially many natural products synthesized by bacteria, can act as toxins and damage or kill the partner. For instance, the green microalga Chlamydomonas reinhardtii establishes a mutualistic partnership with a Methylobacterium, in stark contrast to its antagonistic relationship with the toxin producing Pseudomonas protegens. In other cases, as with a coccolithophore haptophyte alga and a Phaeobacter bacterium, the same alga and bacterium can even be subject to both processes, depending on the secreted bacterial and algal metabolites. Some bacteria also influence algal morphology by producing specific metabolites and micronutrients, as is observed in some macroalgae. This review focuses on algal-bacterial interactions with micro- and macroalgal models from marine, freshwater, and terrestrial environments and summarizes the advances in the field. It also highlights the effects of temperature on these interactions as it is presently known. Full article

(This article belongs to the Special Issue Molecular Signaling Events in Algae in Response to Abiotic Factors and Biotic Interactions)

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14 pages, 1955 KiB

Open AccessEditor’s ChoiceArticle

Diversity of Leaf Fungal Endophytes from Two Coffea arabica Varieties and Antagonism towards Coffee Leaf Rust

by Ruth A. Poma-Angamarca, Jacqueline R. Rojas, Aminael Sánchez-Rodríguez and Mario X. Ruiz-González

Plants 2024, 13(6), 814; https://doi.org/10.3390/plants13060814 - 12 Mar 2024

Cited by 8 | Viewed by 2533

Abstract

Coffee has immense value as a worldwide-appreciated commodity. However, its production faces the effects of climate change and the spread of severe diseases such as coffee leaf rust (CLR). The exploration of fungal endophytes associated with Coffea sp. has already found the existence [...] Read more.

Coffee has immense value as a worldwide-appreciated commodity. However, its production faces the effects of climate change and the spread of severe diseases such as coffee leaf rust (CLR). The exploration of fungal endophytes associated with Coffea sp. has already found the existence of nearly 600 fungal species, but their role in the plants remains practically unknown. We have researched the diversity of leaf fungal endophytes in two Coffea arabica varieties: one susceptible and one resistant to CLR. Then, we conducted cross-infection essays with four common endophyte species (three Colletotrichum sp. and Xylaria sp. 1) and Hemileia vastatrix (CLR) in leaf discs, to investigate the interaction of the endophytes on CLR colonisation success and severity of infection. Two Colletotrichum sp., when inoculated 72 h before H. vastatrix, prevented the colonisation of the leaf disc by the latter. Moreover, the presence of endophytes prior to the arrival of H. vastatrix ameliorated the severity of CLR. Our work highlights both the importance of characterising the hidden biodiversity of endophytes and investigating their potential roles in the plant-endophyte interaction. Full article

(This article belongs to the Special Issue Effects of Biostimulants on Plant Physiology and Metabolic Profile)

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15 pages, 1442 KiB

Open AccessEditor’s ChoiceArticle

Mycorrhizas Affect Physiological Performance, Antioxidant System, Photosynthesis, Endogenous Hormones, and Water Content in Cotton under Salt Stress

by De-Jian Zhang, Cui-Ling Tong, Qiong-Shan Wang and Shu Bie

Plants 2024, 13(6), 805; https://doi.org/10.3390/plants13060805 - 12 Mar 2024

Cited by 22 | Viewed by 2089

Abstract

Saline–alkali stress seriously endangers the normal growth of cotton (Gossypium hirsutum). Arbuscular mycorrhizal fungi (AMF) could enhance salt tolerance by establishing symbiotic relationships with plants. Based on it, a pot experiment was conducted to simulate a salt environment in which cotton [...] Read more.

Saline–alkali stress seriously endangers the normal growth of cotton (Gossypium hirsutum). Arbuscular mycorrhizal fungi (AMF) could enhance salt tolerance by establishing symbiotic relationships with plants. Based on it, a pot experiment was conducted to simulate a salt environment in which cotton was inoculated with Paraglomus occultum to explore its effects on the saline–alkali tolerance of cotton. Our results showed that salt stress noticeably decreased cotton seedling growth parameters (such as plant height, number of leaves, dry weight, root system architecture, etc.), while AMF exhibited a remarkable effect on promoting growth. It was noteworthy that AMF significantly mitigated the inhibitory effect of salt on cotton seedlings. However, AMF colonization in root and soil hyphal length were collectively descended via salt stress. With regard to osmotic regulating substances, Pro and MDA values in roots were significantly increased when seedlings were exposed to salt stress, while AMF only partially mitigated these reactions. Salt stress increased ROS levels in the roots of cotton seedlings and enhanced antioxidant enzyme activity (SOD, POD, and CAT), while AMF mitigated the increases in ROS levels but further strengthened antioxidant enzyme activity. AMF inoculation increased the photosynthesis parameters of cotton seedling leaves to varying degrees, while salt stress decreased them dramatically. When inoculated with AMF under a salt stress environment, only partial mitigation of these photosynthesis values was observed. Under saline–alkali stress, AMF improved the leaf fluorescence parameters (φPSII, Fv′/Fm′, and qP) of cotton seedlings, leaf chlorophyll levels, and root endogenous hormones (IAA and BR); promoted the absorption of water; and maintained nitrogen balance, thus alleviating the damage from salt stress on the growth of cotton plants to some extent. In summary, mycorrhizal cotton seedlings may exhibit mechanisms involving root system architecture, the antioxidant system, photosynthesis, leaf fluorescence, endogenous hormones, water content, and nitrogen balance that increase their resistance to saline–alkali environments. This study provide a theoretical basis for further exploring the application of AMF to enhance the salt tolerance of cotton. Full article

(This article belongs to the Special Issue Abiotic Stress Responses in Plants)

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20 pages, 1562 KiB

Open AccessEditor’s ChoiceReview

The Role of Soil Microbial Consortia in Sustainable Cereal Crop Residue Management

by Arman Shamshitov, Gražina Kadžienė and Skaidrė Supronienė

Plants 2024, 13(6), 766; https://doi.org/10.3390/plants13060766 - 8 Mar 2024

Cited by 9 | Viewed by 3163

Abstract

The global escalation in cereal production, essential to meet growing population demands, simultaneously augments the generation of cereal crop residues, estimated annually at approximately 3107 × 10⁶ Mg/year. Among different crop residue management approaches, returning them to the soil can be essential [...] Read more.

The global escalation in cereal production, essential to meet growing population demands, simultaneously augments the generation of cereal crop residues, estimated annually at approximately 3107 × 10⁶ Mg/year. Among different crop residue management approaches, returning them to the soil can be essential for various ecological benefits, including nutrient recycling and soil carbon sequestration. However, the recalcitrant characteristics of cereal crop residues pose significant challenges in their management, particularly in the decomposition rate. Therefore, in this review, we aim to summarize the influence of different agricultural practices on enhancing soil microbial decomposer communities, thereby effectively managing cereal crop residues. Moreover, this manuscript provides indirect estimates of cereal crop residue production in Northern Europe and Lithuania, and highlights the diverse roles of lignocellulolytic microorganisms in the decomposition process, with a particular focus on enzymatic activities. This review bridges the knowledge gap and indicates future research directions concerning the influence of agricultural practices on cereal crop residue-associated microbial consortia. Full article

(This article belongs to the Collection Selected Papers from Lithuanian Research Centre for Agriculture and Forestry)

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23 pages, 402 KiB

Open AccessEditor’s ChoiceReview

Crop Landraces and Indigenous Varieties: A Valuable Source of Genes for Plant Breeding

by Efstathia Lazaridi, Aliki Kapazoglou, Maria Gerakari, Konstantina Kleftogianni, Kondylia Passa, Efi Sarri, Vasileios Papasotiropoulos, Eleni Tani and Penelope J. Bebeli

Plants 2024, 13(6), 758; https://doi.org/10.3390/plants13060758 - 7 Mar 2024

Cited by 19 | Viewed by 6236

Abstract

Landraces and indigenous varieties comprise valuable sources of crop species diversity. Their utilization in plant breeding may lead to increased yield and enhanced quality traits, as well as resilience to various abiotic and biotic stresses. Recently, new approaches based on the rapid advancement [...] Read more.

Landraces and indigenous varieties comprise valuable sources of crop species diversity. Their utilization in plant breeding may lead to increased yield and enhanced quality traits, as well as resilience to various abiotic and biotic stresses. Recently, new approaches based on the rapid advancement of genomic technologies such as deciphering of pangenomes, multi-omics tools, marker-assisted selection (MAS), genome-wide association studies (GWAS), and CRISPR/Cas9 gene editing greatly facilitated the exploitation of landraces in modern plant breeding. In this paper, we present a comprehensive overview of the implementation of new genomic technologies and highlight their importance in pinpointing the genetic basis of desirable traits in landraces and indigenous varieties of annual, perennial herbaceous, and woody crop species cultivated in the Mediterranean region. The need for further employment of advanced -omic technologies to unravel the full potential of landraces and indigenous varieties underutilized genetic diversity is also indicated. Ultimately, the large amount of genomic data emerging from the investigation of landraces and indigenous varieties reveals their potential as a source of valuable genes and traits for breeding. The role of landraces and indigenous varieties in mitigating the ongoing risks posed by climate change in agriculture and food security is also highlighted. Full article

(This article belongs to the Special Issue Genetic Diversity, Germplasm Resources, and Biotechnological Applications for Sustained Crop Improvement)

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18 pages, 2948 KiB

Open AccessEditor’s ChoiceArticle

Phytoremediation Potential of Different Genotypes of Salix alba and S. viminalis

by Jelena Urošević, Dragica Stanković, Dušan Jokanović, Goran Trivan, Aleh Rodzkin, Đorđe Jović and Filip Jovanović

Plants 2024, 13(5), 735; https://doi.org/10.3390/plants13050735 - 5 Mar 2024

Cited by 13 | Viewed by 2293

Abstract

Elevated concentrations of heavy metals result in soil degradation, a reduction in plant yields, and a lower quality of agricultural products, which directly endangers people, animals, and the ecosystem. The potential of three clones of Salix alba (347, NS 73/6, and B-44) and [...] Read more.

Elevated concentrations of heavy metals result in soil degradation, a reduction in plant yields, and a lower quality of agricultural products, which directly endangers people, animals, and the ecosystem. The potential of three clones of Salix alba (347, NS 73/6, and B-44) and one genotype of S. viminalis for the phytoextraction of heavy metals was investigated, with the aim of identifying the most physiologically suitable willow genotypes for use in soil phytoremediation. The experiment was placed on the contaminated soil substrate collected in Kolubara Mining Basin (Serbia), enriched by high loads of heavy metal salts, and a control medium. Significant differences in the concentrations of heavy metals were recorded between the contaminated and control plant material, especially when it comes to nickel (Ni), copper (Cu), cadmium (Cd), and lead (Pb), confirming that S. alba and S. viminalis are hyperaccumulator species of heavy metals. Clone 347 shows the greatest uptake of Cd and chromium (Cr), and clone B-44 takes up these metals only to a lesser extent, while clone NS 73/6 shows a less pronounced uptake of Cr. The roots have the greatest ability to accumulate Ni and Pb, Cu is absorbed by all plant organs, while Cd is absorbed by the leaves. The organ that showed the greatest ability to accumulate heavy metals was the root, which means that willows have a limited power to translocate heavy metals to above-ground organs. The studied genotypes of S. alba have a higher potential for the phytostabilization of Cu and Cd, as well as the phytoextraction of Cd, compared with S. viminalis. The results confirm the assumption of differences between different willow genotypes in terms of the ability to phytoextract certain heavy metals from soil, which is important information when selecting genotypes for soil phytoremediation. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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19 pages, 8521 KiB

Open AccessEditor’s ChoiceArticle

Analysis of the UDP-Glucosyltransferase (UGT) Gene Family and Its Functional Involvement in Drought and Salt Stress Tolerance in Phoebe bournei

by Hengfeng Guan, Yanzi Zhang, Jingshu Li, Zhening Zhu, Jiarui Chang, Almas Bakari, Shipin Chen, Kehui Zheng and Shijiang Cao

Plants 2024, 13(5), 722; https://doi.org/10.3390/plants13050722 - 4 Mar 2024

Cited by 7 | Viewed by 3289

Abstract

Uridine diphosphate glycosyltransferases (UDP-GTs, UGTs), which are regulated by UGT genes, play a crucial role in glycosylation. In vivo, the activity of UGT genes can affect the availability of metabolites and the rate at which they can be eliminated from the body. UGT [...] Read more.

Uridine diphosphate glycosyltransferases (UDP-GTs, UGTs), which are regulated by UGT genes, play a crucial role in glycosylation. In vivo, the activity of UGT genes can affect the availability of metabolites and the rate at which they can be eliminated from the body. UGT genes can exert their regulatory effects through mechanisms such as post-transcriptional modification, substrate subtype specificity, and drug interactions. Phoebe bournei is an economically significant tree species that is endemic to southern China. Despite extensive studies on the UGT gene family in various species, a comprehensive investigation of the UGT family in P. bournei has not been reported. Therefore, we conducted a systematic analysis to identify 156 UGT genes within the entire P. bournei genome, all of which contained the PSPG box. The PbUGT family consists of 14 subfamilies, consistent with Arabidopsis thaliana. We observed varying expression levels of PbUGT genes across different tissues in P. bournei, with the following average expression hierarchy: leaf > stem xylem > stem bark > root xylem > root bark. Covariance analysis revealed stronger covariance between P. bournei and closely related species. In addition, we stressed the seedlings with 10% NaCl and 10% PEG-6000. The PbUGT genes exhibited differential expression under drought and salt stresses, with specific expression patterns observed under each stress condition. Our findings shed light on the transcriptional response of PbUGT factors to drought and salt stresses, thereby establishing a foundation for future investigations into the role of PbUGT transcription factors. Full article

(This article belongs to the Special Issue Recent Advances in Horticultural Plant Genomics)

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15 pages, 1112 KiB

Open AccessEditor’s ChoiceArticle

Nematicidal Activity of Phytochemicals against the Root-Lesion Nematode Pratylenchus penetrans

by Pedro Barbosa, Jorge M. S. Faria, Tomás Cavaco, Ana Cristina Figueiredo, Manuel Mota and Cláudia S. L. Vicente

Plants 2024, 13(5), 726; https://doi.org/10.3390/plants13050726 - 4 Mar 2024

Cited by 10 | Viewed by 3805

Abstract

Plant-parasitic nematodes (PPNs) are highly damaging pests responsible for heavy losses in worldwide productivity in a significant number of important plant crops. Common pest management strategies rely on the use of synthetic chemical nematicides, which have led to serious concerns regarding their impacts [...] Read more.

Plant-parasitic nematodes (PPNs) are highly damaging pests responsible for heavy losses in worldwide productivity in a significant number of important plant crops. Common pest management strategies rely on the use of synthetic chemical nematicides, which have led to serious concerns regarding their impacts on human health and the environment. Plant natural products, or phytochemicals, can provide a good source of agents for sustainable control of PPNs, due to their intrinsic characteristics such as higher biodegradability, generally low toxicity for mammals, and lower bioaccumulation in the environment. In this work, the nematicidal activity of 39 phytochemicals was determined against the root-lesion nematode (RLN) Pratylenchus penetrans using standard direct and indirect contact methodologies. Overall, the RLN was tolerant to the tested phytochemicals at the highest concentration, 2 mg/mL, seldom reaching full mortality. However, high activities were obtained for benzaldehyde, carvacrol, 3-octanol, and thymol, in comparison to other phytochemicals or the synthetic nematicide oxamyl. These phytochemicals were seen to damage nematode internal tissues but not its cuticle shape. Also, the environmental and (eco)toxicological parameters reported for these compounds suggest lower toxicity and higher safety of use than oxamyl. These compounds appear to be good candidates for the development of biopesticides for a more sustainable pest management strategy. Full article

(This article belongs to the Special Issue Biopesticides for Plant Protection)

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31 pages, 5900 KiB

Open AccessEditor’s ChoiceArticle

Development and Assessment of SNP Genotyping Arrays for Citrus and Its Close Relatives

by Yoko Hiraoka, Sergio Pietro Ferrante, Guohong Albert Wu, Claire T. Federici and Mikeal L. Roose

Plants 2024, 13(5), 691; https://doi.org/10.3390/plants13050691 - 29 Feb 2024

Cited by 8 | Viewed by 2736

Abstract

Rapid advancements in technologies provide various tools to analyze fruit crop genomes to better understand genetic diversity and relationships and aid in breeding. Genome-wide single nucleotide polymorphism (SNP) genotyping arrays offer highly multiplexed assays at a relatively low cost per data point. We [...] Read more.

Rapid advancements in technologies provide various tools to analyze fruit crop genomes to better understand genetic diversity and relationships and aid in breeding. Genome-wide single nucleotide polymorphism (SNP) genotyping arrays offer highly multiplexed assays at a relatively low cost per data point. We report the development and validation of 1.4M SNP Axiom^® Citrus HD Genotyping Array (Citrus 15AX 1 and Citrus 15AX 2) and 58K SNP Axiom^® Citrus Genotyping Arrays for Citrus and close relatives. SNPs represented were chosen from a citrus variant discovery panel consisting of 41 diverse whole-genome re-sequenced accessions of Citrus and close relatives, including eight progenitor citrus species. SNPs chosen mainly target putative genic regions of the genome and are accurately called in both Citrus and its closely related genera while providing good coverage of the nuclear and chloroplast genomes. Reproducibility of the arrays was nearly 100%, with a large majority of the SNPs classified as the most stringent class of markers, “PolyHighResolution” (PHR) polymorphisms. Concordance between SNP calls in sequence data and array data average 98%. Phylogenies generated with array data were similar to those with comparable sequence data and little affected by 3 to 5% genotyping error. Both arrays are publicly available. Full article

(This article belongs to the Special Issue Evaluation of Genetic Diversity and Germplasm in Plants Using Molecular and DNA Markers)

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29 pages, 4742 KiB

Open AccessEditor’s ChoiceArticle

Plant Growth Promotion and Plant Disease Suppression Induced by Bacillus amyloliquefaciens Strain GD4a

by Piao Yang, Pu Yuan, Wenshan Liu, Zhenzhen Zhao, Matthew C. Bernier, Chunquan Zhang, Ashna Adhikari, Stephen Obol Opiyo, Lijing Zhao, Fredrekis Banks and Ye Xia

Plants 2024, 13(5), 672; https://doi.org/10.3390/plants13050672 - 28 Feb 2024

Cited by 11 | Viewed by 3904

Abstract

Botrytis cinerea, the causative agent of gray mold disease (GMD), invades plants to obtain nutrients and disseminates through airborne conidia in nature. Bacillus amyloliquefaciens strain GD4a, a beneficial bacterium isolated from switchgrass, shows great potential in managing GMD in plants. However, the [...] Read more.

Botrytis cinerea, the causative agent of gray mold disease (GMD), invades plants to obtain nutrients and disseminates through airborne conidia in nature. Bacillus amyloliquefaciens strain GD4a, a beneficial bacterium isolated from switchgrass, shows great potential in managing GMD in plants. However, the precise mechanism by which GD4a confers benefits to plants remains elusive. In this study, an A. thaliana-B. cinerea-B. amyloliquefaciens multiple-scale interaction model was used to explore how beneficial bacteria play essential roles in plant growth promotion, plant pathogen suppression, and plant immunity boosting. Arabidopsis Col-0 wild-type plants served as the testing ground to assess GD4a’s efficacy. Additionally, bacterial enzyme activity and targeted metabolite tests were conducted to validate GD4a’s potential for enhancing plant growth and suppressing plant pathogens and diseases. GD4a was subjected to co-incubation with various bacterial, fungal, and oomycete pathogens to evaluate its antagonistic effectiveness in vitro. In vivo pathogen inoculation assays were also carried out to investigate GD4a’s role in regulating host plant immunity. Bacterial extracellular exudate (BEE) was extracted, purified, and subjected to untargeted metabolomics analysis. Benzocaine (BEN) from the untargeted metabolomics analysis was selected for further study of its function and related mechanisms in enhancing plant immunity through plant mutant analysis and qRT-PCR analysis. Finally, a comprehensive model was formulated to summarize the potential benefits of applying GD4a in agricultural systems. Our study demonstrates the efficacy of GD4a, isolated from switchgrass, in enhancing plant growth, suppressing plant pathogens and diseases, and bolstering host plant immunity. Importantly, GD4a produces a functional bacterial extracellular exudate (BEE) that significantly disrupts the pathogenicity of B. cinerea by inhibiting fungal conidium germination and hypha formation. Additionally, our study identifies benzocaine (BEN) as a novel small molecule that triggers basal defense, ISR, and SAR responses in Arabidopsis plants. Bacillus amyloliquefaciens strain GD4a can effectively promote plant growth, suppress plant disease, and boost plant immunity through functional BEE production and diverse gene expression. Full article

(This article belongs to the Special Issue Plant Resistance against Bacterial and Fungal Pathogens: Mechanisms and Applications)

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22 pages, 1792 KiB

Open AccessEditor’s ChoiceReview

Distributing Plant Developmental Regulatory Proteins via Plasmodesmata

by Joyce M. Schreiber, Erik Limpens and Jeroen de Keijzer

Plants 2024, 13(5), 684; https://doi.org/10.3390/plants13050684 - 28 Feb 2024

Cited by 4 | Viewed by 3325

Abstract

During plant development, mobile proteins, including transcription factors, abundantly serve as messengers between cells to activate transcriptional signaling cascades in distal tissues. These proteins travel from cell to cell via nanoscopic tunnels in the cell wall known as plasmodesmata. Cellular control over this [...] Read more.

During plant development, mobile proteins, including transcription factors, abundantly serve as messengers between cells to activate transcriptional signaling cascades in distal tissues. These proteins travel from cell to cell via nanoscopic tunnels in the cell wall known as plasmodesmata. Cellular control over this intercellular movement can occur at two likely interdependent levels. It involves regulation at the level of plasmodesmata density and structure as well as at the level of the cargo proteins that traverse these tunnels. In this review, we cover the dynamics of plasmodesmata formation and structure in a developmental context together with recent insights into the mechanisms that may control these aspects. Furthermore, we explore the processes involved in cargo-specific mechanisms that control the transport of proteins via plasmodesmata. Instead of a one-fits-all mechanism, a pluriform repertoire of mechanisms is encountered that controls the intercellular transport of proteins via plasmodesmata to control plant development. Full article

(This article belongs to the Special Issue Plasmodesmata)

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16 pages, 12270 KiB

Open AccessEditor’s ChoiceArticle

Prediction of Historical, Current, and Future Configuration of Tibetan Medicinal Herb Gymnadenia orchidis Based on the Optimized MaxEnt in the Qinghai–Tibet Plateau

by Ming Li, Yi Zhang, Yongsheng Yang, Tongxin Wang, Chu Wu and Xiujuan Zhang

Plants 2024, 13(5), 645; https://doi.org/10.3390/plants13050645 - 26 Feb 2024

Cited by 11 | Viewed by 1996

Abstract

Climate change plays a pivotal role in shaping the shifting patterns of plant distribution, and gaining insights into how medicinal plants in the plateau region adapt to climate change will be instrumental in safeguarding the rich biodiversity of the highlands. Gymnosia orchidis Lindl. [...] Read more.

Climate change plays a pivotal role in shaping the shifting patterns of plant distribution, and gaining insights into how medicinal plants in the plateau region adapt to climate change will be instrumental in safeguarding the rich biodiversity of the highlands. Gymnosia orchidis Lindl. (G. orchidis) is a valuable Tibetan medicinal resource with significant medicinal, ecological, and economic value. However, the growth of G. orchidis is severely constrained by stringent natural conditions, leading to a drastic decline in its resources. Therefore, it is crucial to study the suitable habitat areas of G. orchidis to facilitate future artificial cultivation and maintain ecological balance. In this study, we investigated the suitable zones of G. orchidis based on 79 occurrence points in the Qinghai–Tibet Plateau (QTP) and 23 major environmental variables, including climate, topography, and soil type. We employed the Maximum Entropy model (MaxEnt) to simulate and predict the spatial distribution and configuration changes in G. orchidis during different time periods, including the last interglacial (LIG), the Last Glacial Maximum (LGM), the Mid-Holocene (MH), the present, and future scenarios (2041–2060 and 2061–2080) under three different climate scenarios (SSP126, SSP370, and SSP585). Our results indicated that annual precipitation (Bio12, 613–2466 mm) and mean temperature of the coldest quarter (Bio11, −5.8–8.5 °C) were the primary factors influencing the suitable habitat of G. orchidis, with a cumulative contribution of 78.5%. The precipitation and temperature during the driest season had the most significant overall impact. Under current climate conditions, the suitable areas of G. orchidis covered approximately 63.72 × 10⁴/km², encompassing Yunnan, Gansu, Sichuan, and parts of Xizang provinces, with the highest suitability observed in the Hengduan, Yunlin, and Himalayan mountain regions. In the past, the suitable area of G. orchidis experienced significant changes during the Mid-Holocene, including variations in the total area and centroid migration direction. In future scenarios, the suitable habitat of G. orchidis is projected to expand significantly under SSP370 (30.33–46.19%), followed by SSP585 (1.41–22.3%), while contraction is expected under SSP126. Moreover, the centroids of suitable areas exhibited multidirectional movement, with the most extensive displacement observed under SSP585 (100.38 km²). This study provides a theoretical foundation for the conservation of biodiversity and endangered medicinal plants in the QTP. Full article

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35 pages, 1836 KiB

Open AccessEditor’s ChoiceReview

Chemically Mediated Plant–Plant Interactions: Allelopathy and Allelobiosis

by Chui-Hua Kong, Zheng Li, Feng-Li Li, Xin-Xin Xia and Peng Wang

Plants 2024, 13(5), 626; https://doi.org/10.3390/plants13050626 - 24 Feb 2024

Cited by 36 | Viewed by 12327

Abstract

Plant–plant interactions are a central driver for plant coexistence and community assembly. Chemically mediated plant–plant interactions are represented by allelopathy and allelobiosis. Both allelopathy and allelobiosis are achieved through specialized metabolites (allelochemicals or signaling chemicals) produced and released from neighboring plants. Allelopathy exerts [...] Read more.

Plant–plant interactions are a central driver for plant coexistence and community assembly. Chemically mediated plant–plant interactions are represented by allelopathy and allelobiosis. Both allelopathy and allelobiosis are achieved through specialized metabolites (allelochemicals or signaling chemicals) produced and released from neighboring plants. Allelopathy exerts mostly negative effects on the establishment and growth of neighboring plants by allelochemicals, while allelobiosis provides plant neighbor detection and identity recognition mediated by signaling chemicals. Therefore, plants can chemically affect the performance of neighboring plants through the allelopathy and allelobiosis that frequently occur in plant–plant intra-specific and inter-specific interactions. Allelopathy and allelobiosis are two probably inseparable processes that occur together in plant–plant chemical interactions. Here, we comprehensively review allelopathy and allelobiosis in plant–plant interactions, including allelopathy and allelochemicals and their application for sustainable agriculture and forestry, allelobiosis and plant identity recognition, chemically mediated root–soil interactions and plant–soil feedback, and biosynthesis and the molecular mechanisms of allelochemicals and signaling chemicals. Altogether, these efforts provide the recent advancements in the wide field of allelopathy and allelobiosis, and new insights into the chemically mediated plant–plant interactions. Full article

(This article belongs to the Special Issue Plant Chemical Ecology)

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