Plants

8 pages, 540 KiB

Open AccessBrief Report

Evaluating Seed Enhancement Technology’s Effects on Seed Viability during Multi-Year Storage: A Case Study Using Herbicide Protection Pellets

by Owen Baughman, Anna Hosford and Emily Ralston

Plants 2023, 12(20), 3662; https://doi.org/10.3390/plants12203662 - 23 Oct 2023

Viewed by 1006

Abstract

The viability of seed often decreases during multi-year storage. For seed enhancement technologies (SETs) that apply treatments to native seed prior to sowing in restoration projects, it is important to determine if SETs affect the rate of viability loss in storage to understand [...] Read more.

The viability of seed often decreases during multi-year storage. For seed enhancement technologies (SETs) that apply treatments to native seed prior to sowing in restoration projects, it is important to determine if SETs affect the rate of viability loss in storage to understand if treated seeds can tolerate storage or if they must be sown immediately after treatment. Examining herbicide protection pellet (HPP) seed technology, we conducted germination trials on 10 seedlots of four species to compare three treatments: original bare seed kept in seed storage for 2–3 years, seed retrieved from 2–3-year-old HPPs made from pre-storage original bare seed (old HPPs), and seed retrieved from HPPs that were freshly-made using post-storage original bare seed (new HPPs). For three perennial bunchgrasses, we saw equal or higher germinability of seed from old HPPs compared to the original bare seed and new HPPs, suggesting application of HPP technology to these species prior to multi-year storage is suitable. For the seeds of a perennial shrub, although we saw greater germination of original bare seeds compared to old HPPs, the lowest germination was from new HPPs, still suggesting HPP application prior to storage as a suitable practice. We suggest these tests be performed with all new SETs under development for ecological restoration. Full article

(This article belongs to the Special Issue Innovative Seed Enhancement Technologies)

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40 pages, 2126 KiB

Open AccessReview

Functional Modules in the Meristems: “Tinkering” in Action

by Ksenia Kuznetsova, Elena Efremova, Irina Dodueva, Maria Lebedeva and Ludmila Lutova

Plants 2023, 12(20), 3661; https://doi.org/10.3390/plants12203661 - 23 Oct 2023

Cited by 2 | Viewed by 1632

Abstract

Background: A feature of higher plants is the modular principle of body organisation. One of these conservative morphological modules that regulate plant growth, histogenesis and organogenesis is meristems—structures that contain pools of stem cells and are generally organised according to a common principle. [...] Read more.

Background: A feature of higher plants is the modular principle of body organisation. One of these conservative morphological modules that regulate plant growth, histogenesis and organogenesis is meristems—structures that contain pools of stem cells and are generally organised according to a common principle. Basic content: The development of meristems is under the regulation of molecular modules that contain conservative interacting components and modulate the expression of target genes depending on the developmental context. In this review, we focus on two molecular modules that act in different types of meristems. The WOX-CLAVATA module, which includes the peptide ligand, its receptor and the target transcription factor, is responsible for the formation and control of the activity of all meristem types studied, but it has its own peculiarities in different meristems. Another regulatory module is the so-called florigen-activated complex, which is responsible for the phase transition in the shoot vegetative meristem (e.g., from the vegetative shoot apical meristem to the inflorescence meristem). Conclusions: The review considers the composition and functions of these two functional modules in different developmental programmes, as well as their appearance, evolution and use in plant breeding. Full article

(This article belongs to the Special Issue Plant Meristems:The Cradle of Life)

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17 pages, 14398 KiB

Open AccessArticle

Endophyte Community Changes in the Seeds of Eight Plant Species following Inoculation with a Multi-Endophytic Bacterial Consortium and an Individual Sphingomonas wittichii Strain Obtained from Noccaea caerulescens

by Tori Langill, Małgorzata Wójcik, Jaco Vangronsveld and Sofie Thijs

Plants 2023, 12(20), 3660; https://doi.org/10.3390/plants12203660 - 23 Oct 2023

Viewed by 1304

Abstract

Noccaea caerulescens, a hyperaccumulator plant species known for its metal tolerance and accumulation abilities, harbours a microbiome of interest within its seed. These seed-associated bacteria, often referred to as seed endophytes, play a unique role in seed germination and plant growth and [...] Read more.

Noccaea caerulescens, a hyperaccumulator plant species known for its metal tolerance and accumulation abilities, harbours a microbiome of interest within its seed. These seed-associated bacteria, often referred to as seed endophytes, play a unique role in seed germination and plant growth and health. This work aimed to address how inoculating seeds of eight different plant species—Medicago sativa (alfalfa), Zea mays (corn), Raphanus sativus (radish), Helianthus annus (sunflower), Cucurbita pepo subsp. pepo (squash), Beta vulgaris subsp. cicla (rainbow chard), Arabidopsis thaliana (thale cress), and Noccaea caerulescens (penny cress)—with a bacterial consortium made from the seed endophytes of N. caerulescens would affect the seed microbiome of each test plant species, as well as inoculation with a strain of the bacterium Sphingomonas wittichii, which was previously isolated from seeds of N. caerulescens. Additionally, we aimed to offer preliminary plant tests in order to determine the best seed treatment plan for future research. The results showed that inoculation with the bacterial consortium held the most potential for increasing plant size (p < 0.001) and increasing germination rate (p < 0.05). The plant that responded best to inoculation was N. caerulescens (penny cress), likely because the microbes being introduced into the seed were not foreign. This paper also offers the first insight into the seed endophytes of Beta vulgaris subsp. cicla, highlighting an abundance of Proteobacteria, Firmicutes, and Actinobacteriota. Full article

(This article belongs to the Special Issue Interaction of Plants and Endophytic Microorganisms: Molecular Aspects, Biological Functions, Community Composition, and Practical Applications Ⅱ)

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21 pages, 739 KiB

Open AccessArticle

Modeling Study of the Effects of Ageratum conyzoides on the Transmission and Control of Citrus Huanglongbing

by Ying Wang, Shujing Gao, Yujiang Liu and Huaiping Zhu

Plants 2023, 12(20), 3659; https://doi.org/10.3390/plants12203659 - 23 Oct 2023

Viewed by 1229

Abstract

Ageratum conyzoides (A. conyzoides) is commonly found or intentionally planted in citrus orchards due to its ability to provide habitat and breeding grounds for the natural enemies of citrus pests. This study aims to expand from a switching Huanglongbing model by [...] Read more.

Ageratum conyzoides (A. conyzoides) is commonly found or intentionally planted in citrus orchards due to its ability to provide habitat and breeding grounds for the natural enemies of citrus pests. This study aims to expand from a switching Huanglongbing model by incorporating the effects of A. conyzoides, vector preferences for settling, and pesticide application intervals on disease transmission. Additionally, we establish the basic reproduction number

R_{0}

and its calculation for a general switching compartmental epidemic model. Theoretical findings demonstrate that the basic reproduction number serves as a threshold parameter to characterize the dynamics of the models: if

R_{0} < 1

, the disease will disappear, whereas if

R_{0} > 1

, it will spread. Numerical results indicate that the recruitment rate of A. conyzoides not only affects the spread speed of Huanglongbing but also leads to paradoxical effects. Specifically, in cases of high infection rates, a low recruitment rate of A. conyzoides can result in a decrease, rather than an increase, in the basic reproduction number. Conversely, a high recruitment rate can accelerate the spread of Huanglongbing. Furthermore, we show how different vector bias and pesticide spraying periods affect the basic reproduction number. Full article

(This article belongs to the Special Issue Disease Control Strategies in Citrus Plants)

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11 pages, 289 KiB

Open AccessEditorial

Improving Fertilizer Use Efficiency—Methods and Strategies for the Future

by Przemysław Barłóg

Plants 2023, 12(20), 3658; https://doi.org/10.3390/plants12203658 - 23 Oct 2023

Cited by 6 | Viewed by 5564

Abstract

This editorial introduces our Special Issue entitled “Improving Fertilizer Use Efficiency—Methods and Strategies for the Future”. The fertilizer use efficiency (FUE) is a measure of the potential of an applied fertilizer to increase the productivity and utilization of the nutrients present in the [...] Read more.

This editorial introduces our Special Issue entitled “Improving Fertilizer Use Efficiency—Methods and Strategies for the Future”. The fertilizer use efficiency (FUE) is a measure of the potential of an applied fertilizer to increase the productivity and utilization of the nutrients present in the soil/plant system. FUE indices are mainly used to assess the effectiveness of nitrogen (N), phosphorus (P), and potassium (K) fertilization. This is due to the low efficiency of use of NPK fertilizers, their environmental side effects and also, in relation to P, limited natural resources. The FUE is the result of a series of interactions between the plant genotype and the environment, including both abiotic and biotic factors. A full recognition of these factors is the basis for proper fertilization in farming practice, aimed at maximizing the FUE. This Special Issue focuses on some key topics in crop fertilization. Due to specific goals, they can be grouped as follows: removing factors that limit the nutrient uptake of plants; improving and/or maintaining an adequate soil fertility; the precise determination of fertilizer doses and application dates; foliar application; the use of innovative fertilizers; and the adoption of efficient genotypes. The most important nutrient in crop production is N. Hence, most scientific research focuses on improving the nitrogen use efficiency (NUE). Obtaining high NUE values is possible, but only if the plants are well supplied with nitrogen-supporting nutrients. In this Special Issue, particular attention is paid to improving the plant supply with P and K. Full article

(This article belongs to the Special Issue Improving Fertilizer Use Efficiency–Methods and Strategies for the Future)

23 pages, 5880 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Development and Evaluation of Zinc and Iron Nanoparticles Functionalized with Plant Growth-Promoting Rhizobacteria (PGPR) and Microalgae for Their Application as Bio-Nanofertilizers

by Carlos Esteban Guardiola-Márquez, Edgar R. López-Mena, M. Eugenia Segura-Jiménez, Isaac Gutierrez-Marmolejo, Manuel A. Flores-Matzumiya, Shirley Mora-Godínez, Carmen Hernández-Brenes and Daniel A. Jacobo-Velázquez

Plants 2023, 12(20), 3657; https://doi.org/10.3390/plants12203657 - 23 Oct 2023

Cited by 9 | Viewed by 3857

Abstract

Micronutrient deficiencies are widespread and growing global concerns. Nanoscale nutrients present higher absorption rates and improved nutrient availability and nutrient use efficiency. Co-application of nanofertilizers (NFs) with biological agents or organic compounds increases NF biocompatibility, stability, and efficacy. This study aimed to develop [...] Read more.

Micronutrient deficiencies are widespread and growing global concerns. Nanoscale nutrients present higher absorption rates and improved nutrient availability and nutrient use efficiency. Co-application of nanofertilizers (NFs) with biological agents or organic compounds increases NF biocompatibility, stability, and efficacy. This study aimed to develop and evaluate zinc and iron bio-nanofertilizers formulated with plant growth-promoting rhizobacteria (PGPR) and microalgae. Nanoparticles (NPs) were synthesized with the co-precipitation method and functionalized with Pseudomonas species and Spirulina platensis preparation. NPs were characterized and evaluated on seed germination, soil microbial growth, and early plant response under seedbed conditions. NPs corresponded to zinc oxide (ZnO; 77 nm) and maghemite (γ-Fe₂O₃; 68 nm). Functionalized nanoparticles showed larger sizes, around 145–233 nm. The seedling vigor index of tomato and maize was significantly increased (32.9–46.1%) by bacteria-functionalized ZnO- and γ-Fe₂O₃-NPs at 75 ppm. NFs at 250 and 75 ppm significantly increased bacterial growth. NFs also improved early plant growth by increasing plant height (14–44%), leaf diameter (22–47%), and fresh weight (46–119%) in broccoli and radish, which were mainly influenced by bacteria capped ZnO- and γ-Fe₂O₃-NPs at 250 ppm. Beneficial effects on plant growth can be attributed to the synergistic interaction of the biological components and the zinc and iron NPs in the bio-nanofertilizers. Full article

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11 pages, 1501 KiB

Open AccessArticle

Inhibitory Activity of Natural cis-Khellactone on Soluble Epoxide Hydrolase and Proinflammatory Cytokine Production in Lipopolysaccharides-Stimulated RAW264.7 Cells

by Jang Hoon Kim, Ji Hyeon Park, Sung Cheol Koo, Yun-Chan Huh, Mok Hur, Woo Tae Park, Youn-Ho Moon, Tae Il Kim and Byoung Ok Cho

Plants 2023, 12(20), 3656; https://doi.org/10.3390/plants12203656 - 23 Oct 2023

Cited by 1 | Viewed by 1323

Abstract

The pursuit of anti-inflammatory agents has led to intensive research on the inhibition of soluble epoxide hydrolase (sEH) and cytokine production using medicinal plants. In this study, we evaluated the efficacy of cis-khellactone, a compound isolated for the first time from the [...] Read more.

The pursuit of anti-inflammatory agents has led to intensive research on the inhibition of soluble epoxide hydrolase (sEH) and cytokine production using medicinal plants. In this study, we evaluated the efficacy of cis-khellactone, a compound isolated for the first time from the roots of Peucedanum japonicum. The compound was found to be a competitive inhibitor of sEH, exhibiting an IC₅₀ value of 3.1 ± 2.5 µM and k_i value of 3.5 µM. Molecular docking and dynamics simulations illustrated the binding pose of (−)cis-khellactone within the active site of sEH. The results suggest that binding of the inhibitor to the enzyme is largely dependent on the Trp336–Gln384 loop within the active site. Further, cis-khellactone was found to inhibit pro-inflammatory cytokines, including NO, iNOS, IL-1β, and IL-4. These findings affirm that cis-khellactone could serve as a natural therapeutic candidate for the treatment of inflammation. Full article

(This article belongs to the Special Issue Synthesis and Regulation of Active Compounds in Medicinal Plants)

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21 pages, 5183 KiB

Open AccessArticle

Evaluation of Morpho-Physiological and Yield-Associated Traits of Rice (Oryza sativa L.) Landraces Combined with Marker-Assisted Selection under High-Temperature Stress and Elevated Atmospheric CO₂ Levels

by Merentoshi Mollier, Rajib Roychowdhury, Lanunola Tzudir, Radheshyam Sharma, Ujjal Barua, Naseema Rahman, Sikandar Pal, Bhabesh Gogoi, Prakash Kalita, Devendra Jain and Ranjan Das

Plants 2023, 12(20), 3655; https://doi.org/10.3390/plants12203655 - 23 Oct 2023

Cited by 1 | Viewed by 1965

Abstract

Rice (Oryza sativa L.) is an important cereal crop worldwide due to its long domestication history. North-Eastern India (NEI) is one of the origins of indica rice and contains various native landraces that can withstand climatic changes. The present study compared NEI [...] Read more.

Rice (Oryza sativa L.) is an important cereal crop worldwide due to its long domestication history. North-Eastern India (NEI) is one of the origins of indica rice and contains various native landraces that can withstand climatic changes. The present study compared NEI rice landraces to a check variety for phenological, morpho-physiological, and yield-associated traits under high temperatures (HTs) and elevated CO₂ (eCO₂) levels using molecular markers. The first experiment tested 75 rice landraces for HT tolerance. Seven better-performing landraces and the check variety (N22) were evaluated for the above traits in bioreactors for two years (2019 and 2020) under control (T1) and two stress treatments [mild stress or T2 (eCO₂ 550 ppm + 4 °C more than ambient temperature) and severe stress or T3 (eCO₂ 750 ppm + 6 °C more than ambient temperature)]. The findings showed that moderate stress (T2) improved plant height (PH), leaf number (LN), leaf area (LA), spikelets panicle⁻¹ (S/P), thousand-grain weight (TGW), harvest index (HI), and grain production. HT and eCO₂ in T3 significantly decreased all genotypes’ metrics, including grain yield (GY). Pollen traits are strongly and positively associated with spikelet fertility at maturity and GY under stress conditions. Shoot biomass positively affected yield-associated traits including S/P, TGW, HI, and GY. This study recorded an average reduction of 8.09% GY across two seasons in response to the conditions simulated in T3. Overall, two landraces—Kohima special and Lisem—were found to be more responsive compared to other the landraces as well as N22 under stress conditions, with a higher yield and biomass increment. SCoT-marker-assisted genotyping amplified 77 alleles, 55 of which were polymorphic, with polymorphism information content (PIC) values from 0.22 to 0.67. The study reveals genetic variation among the rice lines and supports Kohima Special and Lisem’s close relationship. These two better-performing rice landraces are useful pre-breeding resources for future rice-breeding programs to increase stress tolerance, especially to HT and high eCO₂ levels under changing climatic situations. Full article

(This article belongs to the Special Issue Advances in Genetics and Breeding of Grain Crops)

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18 pages, 2210 KiB

Open AccessArticle

Ecogeography of Dioscorea remotiflora Kunth: An Endemic Species from Mexico

by Jocelyn Maira Velázquez-Hernández, José Ariel Ruíz-Corral, Noé Durán-Puga, Miguel Ángel Macías, Diego Raymundo González-Eguiarte, Fernando Santacruz-Ruvalcaba, Giovanni Emmanuel García-Romero and Agustín Gallegos-Rodríguez

Plants 2023, 12(20), 3654; https://doi.org/10.3390/plants12203654 - 23 Oct 2023

Cited by 1 | Viewed by 1540

Abstract

Dioscorea remotiflora, a perennial climbing herbaceous plant native to Mexico, produces tubers with great nutritional and ethnobotanical value. However, most ecological aspects of this plant remain unknown, which limits its cultivation and use. This is why the objective of this research was [...] Read more.

Dioscorea remotiflora, a perennial climbing herbaceous plant native to Mexico, produces tubers with great nutritional and ethnobotanical value. However, most ecological aspects of this plant remain unknown, which limits its cultivation and use. This is why the objective of this research was to characterize the ecogeography of D. remotiflora as a source to determine its edaphoclimatic adaptability and current and potential distribution. A comprehensive database encompassing 480 geo-referenced accessions was assembled from different data sources. Using the Agroclimatic Information System for México and Central America (SIAMEXCA), 42 environmental variables were formulated. The MaxEnt model within the Kuenm R package was employed to predict the species distribution. The findings reveal a greater presence of D. remotiflora in harsh environments, characterized by arid to semiarid conditions, poor soils, and hot climates with long dry periods. Niche modeling revealed that seven key variables determine the geographical distribution of D. remotiflora: precipitation of the warmest quarter, precipitation of the driest month, minimum temperature of the coldest month, November–April solar radiation, annual mean relative humidity, annual moisture availability index, and May–October mean temperature. The current potential distribution of D. remotiflora is 428,747.68 km². Favorable regions for D. remotiflora coincide with its current presence sites, while other suitable areas, such as the Yucatán Peninsula, northeast region, and Gulf of Mexico, offer potential expansion opportunities for the species distribution. The comprehensive characterization of Dioscorea remotiflora, encompassing aspects such as its soil habitats and climate adaptation, becomes essential not only for understanding its ecology but also for maximizing its economic potential. This will enable not only its sustainable use but also the exploration of commercial applications in sectors such as the pharmaceutical and food industries, thus providing a broader approach for its conservation and optimal utilization in the near future. Full article

(This article belongs to the Special Issue Wild Edible and Medicinal Plants: Ecophysiological and Cultural Aspects for Commercial Cultivation)

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20 pages, 4301 KiB

Open AccessEditor’s ChoiceArticle

Aureobasidium pullulans Treatment Mitigates Drought Stress in Abies koreana via Rhizosphere Microbiome Modulation

by Mohamed Mannaa, Gil Han, Hyejung Jung, Jungwook Park, Jin-Cheol Kim, Ae Ran Park and Young-Su Seo

Plants 2023, 12(20), 3653; https://doi.org/10.3390/plants12203653 - 23 Oct 2023

Cited by 2 | Viewed by 2920

Abstract

The Korean fir tree Abies koreana, an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance A. koreana drought tolerance using a black yeast-like fungus identified as Aureobasidium pullulans (AK10). [...] Read more.

The Korean fir tree Abies koreana, an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance A. koreana drought tolerance using a black yeast-like fungus identified as Aureobasidium pullulans (AK10). The 16S/ITS metabarcoding analysis assessed the impact of drought and AK10 treatment on the seedlings’ rhizosphere microbiome. Results revealed a profound drought influence on the microbiome, particularly affecting fungal mycobiota. Drought-stressed seedlings exhibited elevated Agaricaceae levels, opportunistic fungi generally associated with decomposition. AK10 treatment significantly mitigated this proliferation and increased the relative abundance of beneficial fungi like Cystofilobasidium and Mortierella, known biocontrol agents and phosphate solubilizers. A notable reduction in the phytopathogenic Fusarium levels was observed with AK10, alongside an increase in beneficial bacteria, including Azospirillum and Nitrospirillum. Furthermore, the conducted correlation analysis shed light on microbial interrelationships within the rhizosphere, elucidating potential co-associations and antagonisms. Taken together, the isolated A. pullulans AK10 identified in this study serves as a potential biostimulant, enhancing the drought tolerance in A. koreana through beneficial alterations in the rhizosphere microbiome. This approach presents a promising strategy for the conservation of this endangered species. Full article

(This article belongs to the Section Plant Protection and Biotic Interactions)

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14 pages, 2229 KiB

Open AccessArticle

Influence of Industrial Wastewater Irrigation on Heavy Metal Content in Coriander (Coriandrum sativum L.): Ecological and Health Risk Assessment

by Ilker Ugulu, Zafar Iqbal Khan, Abdulwahed Fahad Alrefaei, Shehnaz Bibi, Kafeel Ahmad, Hafsa Memona, Shahzadi Mahpara, Naunain Mehmood, Mikhlid Hammad Almutairi, Aima Iram Batool, Asma Ashfaq and Ijaz Rasool Noorka

Plants 2023, 12(20), 3652; https://doi.org/10.3390/plants12203652 - 23 Oct 2023

Cited by 5 | Viewed by 1262

Abstract

The primary objective of this study was to determine the heavy metal contents in the water–soil–coriander samples in an industrial wastewater irrigated area and to assess the health risks of these metals to consumers. Sampling was done from areas adjoining the Chistian sugar [...] Read more.

The primary objective of this study was to determine the heavy metal contents in the water–soil–coriander samples in an industrial wastewater irrigated area and to assess the health risks of these metals to consumers. Sampling was done from areas adjoining the Chistian sugar mill district Sargodha and two separate sites irrigated with groundwater (Site 1), and sugar mill effluents (Site 2) were checked for possible metal contamination. The water–soil–coriander continuum was tested for the presence of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Ni), lead (Pb), and zinc (Zn). The mean concentrations of all metals were higher than the permissible limits for all studied metals except for Mn in the sugar mill wastewater, with Fe (8.861 mg/L) and Zn (9.761 mg/L) exhibiting the highest values. The mean levels of Fe (4.023 mg/kg), Cd (2.101 mg/kg), Cr (2.135 mg/kg), Cu (2.180 mg/kg), and Ni (1.523 mg/kg) were high in the soil at Site 2 in comparison to the groundwater irrigated site where Fe (3.232 mg/kg) and Cd (1.845 mg/kg) manifested high elemental levels. For coriander specimens, only Cd had a higher mean level in both the groundwater (1.245 mg/kg) and the sugar mill wastewater (1.245 mg/kg) irrigated sites. An estimation of the pollution indices yielded a high risk from Cd (health risk index (HRI): 173.2), Zn (HRI: 7.012), Mn (HRI: 6.276), Fe (HRI: 1.709), Cu (HRI: 1.282), and Ni (HRI: 1.009), as all values are above 1.0 indicating a hazard to human health from consuming coriander irrigated with wastewater. Regular monitoring of vegetables irrigated with wastewater is strongly advised to reduce health hazards to people. Full article

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19 pages, 1064 KiB

Open AccessArticle

Alleviation of Cadmium Toxicity in Thai Rice Cultivar (PSL2) Using Biofertilizer Containing Indigenous Cadmium-Resistant Microbial Consortia

by Ladda Seang-On, Weeradej Meeinkuirt and Preeyaporn Koedrith

Plants 2023, 12(20), 3651; https://doi.org/10.3390/plants12203651 - 23 Oct 2023

Cited by 3 | Viewed by 1434

Abstract

Biofertilizer as an amendment has growing awareness. Little attention has been paid to bioremediation potential of indigenous heavy-metal-resistant microbes, especially when isolated from long-term polluted soil, as a bioinoculant in biofertilizers. Biofertilizers are a type of versatile nutrient provider and soil conditioner that [...] Read more.

Biofertilizer as an amendment has growing awareness. Little attention has been paid to bioremediation potential of indigenous heavy-metal-resistant microbes, especially when isolated from long-term polluted soil, as a bioinoculant in biofertilizers. Biofertilizers are a type of versatile nutrient provider and soil conditioner that is cost-competitive and highly efficient with nondisruptive detoxifying capability. Herein, we investigated the effect of biofertilizers containing indigenous cadmium (Cd)-resistant microbial consortia on rice growth and physiological response. The Thai rice cultivar PSL2 (Oryza sativa L.) was grown in Cd-enriched soils amended with 3% biofertilizer. The composition of the biofertilizers’ bacterial community at different taxonomic levels was explored using 16S rRNA gene Illumina MiSeq sequencing. Upon Cd stress, the test biofertilizer had maximum mitigating effects as shown by modulating photosynthetic pigment, MDA and proline content and enzymatic antioxidants, thereby allowing increased shoot and root biomass (46% and 53%, respectively) and reduced grain Cd content, as compared to the control. These phenomena might be attributed to increased soil pH and organic matter, as well as enriched beneficial detoxifiers, i.e., Bacteroidetes, Firmicutes and Proteobacteria, in the biofertilizers. The test biofertilizer was effective in alleviating Cd stress by improving soil biophysicochemical traits to limit Cd bioavailability, along with adjusting physiological traits such as antioxidative defense. This study first demonstrated that incorporating biofertilizer derived from indigenous Cd-resistant microbes could restrict Cd contents and consequently enhance plant growth and tolerance in polluted soil. Full article

(This article belongs to the Special Issue Heavy Metal Damage and Tolerance in Plants)

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25 pages, 12513 KiB

Open AccessEditor’s ChoiceArticle

Drought Sensitivity of Spring Wheat Cultivars Shapes Rhizosphere Microbial Community Patterns in Response to Drought

by Jing Fang, Gongfu Shi, Shuli Wei, Jie Ma, Xiangqian Zhang, Jianguo Wang, Liyu Chen, Ying Liu, Xiaoqing Zhao and Zhanyuan Lu

Plants 2023, 12(20), 3650; https://doi.org/10.3390/plants12203650 - 23 Oct 2023

Cited by 4 | Viewed by 1679

Abstract

Drought is the most important natural disaster affecting crop growth and development. Crop rhizosphere microorganisms can affect crop growth and development, enhance the effective utilization of nutrients, and resist adversity and hazards. In this paper, six spring wheat varieties were used as research [...] Read more.

Drought is the most important natural disaster affecting crop growth and development. Crop rhizosphere microorganisms can affect crop growth and development, enhance the effective utilization of nutrients, and resist adversity and hazards. In this paper, six spring wheat varieties were used as research material in the dry farming area of the western foot of the Greater Khingan Mountains, and two kinds of water control treatments were carried out: dry shed rain prevention (DT) and regulated water replenishment (CK). Phenotypic traits, including physiological and biochemical indices, drought resistance gene expression, soil enzyme activity, soil nutrient content, and the responses of potential functional bacteria and fungi under drought stress, were systematically analyzed. The results showed that compared with the control (CK), the leaf wilting, drooping, and yellowing of six spring wheat varieties were enhanced under drought (DT) treatment. The plant height, fresh weight (FW), dry weight (DW), net photosynthetic rate (Pn) and stomatal conductance (Gs), soil total nitrogen (TN), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP), organic carbon (SOC), and soil alkaline phosphatase (S-ALP) contents were significantly decreased, among which, FW, Gs and MBC decreased by more than 7.84%, 17.43% and 11.31%, respectively. By contrast, the soil total phosphorus (TP), total potassium (TK), and soil catalase (S-CAT) contents were significantly increased (p < 0.05). TaWdreb2 and TaBADHb genes were highly expressed in T.D40, T.L36, and T.L33 and were expressed at low levels in T.N2, T.B12, and T.F5. Among them, the relative expression of the TaWdreb2 gene in T.L36 was significantly increased by 2.683 times compared with CK. Soil TN and TP are the most sensitive to drought stress and can be used as the characteristic values of drought stress. Based on this, a drought-tolerant variety (T.L36) and a drought-sensitive variety (T.B12) were selected to further analyze the changes in rhizosphere microorganisms. Drought treatment and cultivar differences significantly affected the composition of the rhizosphere microbial community. Drought caused a decrease in the complexity of the rhizosphere microbial network, and the structure of bacteria was more complex than that of fungi. The Shannon index and network modular number of bacteria in these varieties (T.L36) increased, with rich small-world network properties. Actinobacteria, Chloroflexi, Firmicutes, Basidiomycota, and Ascomycota were the dominant bacteria under drought treatment. The beneficial bacteria Bacillus, Penicillium, and Blastococcus were enriched in the rhizosphere of T.L36. Brevibacillus and Glycomyce were enriched in the rhizosphere of T.B12. In general, drought can inhibit the growth and development of spring wheat, and spring wheat can resist drought hazards by regulating the expression of drought-related genes, regulating physiological metabolites, and enriching beneficial microorganisms. Full article

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13 pages, 3706 KiB

Open AccessArticle

Biochar Decreases Fertilizer Leaching and Promotes Miscanthus Growth in Saline-Alkaline Soil

by Manlin Xu, Qiqi Sun, Qiangbo Liu, Guo He, Congpeng Wang and Kang He

Plants 2023, 12(20), 3649; https://doi.org/10.3390/plants12203649 - 23 Oct 2023

Viewed by 1704

Abstract

Biochar has been widely reported to improve soil conditions and affect plant growth. However, its effectiveness is limited by soil type and production technology. Considering the application effect of biochar in saline alkali soil, there is currently a lack of in-depth mechanism explanations [...] Read more.

Biochar has been widely reported to improve soil conditions and affect plant growth. However, its effectiveness is limited by soil type and production technology. Considering the application effect of biochar in saline alkali soil, there is currently a lack of in-depth mechanism explanations in the research. Therefore, we designed an experiment to explore the effect of biochar on plant growth in saline alkali soil and conducted soil column experiments in a greenhouse environment using composite inorganic fertilizer (NPK). The results showed that biochar significantly affected the distribution of soil nutrient content at different depths, with a significant increase in fertility levels in the surface and middle layers and a decrease in fertility levels in deep soils. Compared to using fertilizers alone, the combined use of biochar and fertilizers further expands the enrichment effect and significantly reduces the leaching of fertilizers into deeper layers. At the same time, the application of biochar also improved soil properties, including an increase in electrical conductivity and organic matter content, as well as an increase in soil enzyme activity. On the other hand, the application of biochar also increases the activity of antioxidant enzymes and the content of osmoregulation substances in plants, reducing the environmental stress that plants are subjected to. Therefore, our results indicate that biochar can reduce the leaching of fertilizers into deep soil layers, improve soil properties, and promotes the growth of Miscanthus in saline alkali soils. Full article

(This article belongs to the Special Issue Molecular Biology of Plant Growth and Development)

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29 pages, 1311 KiB

Open AccessEditor’s ChoiceReview

Uncovering the Role of Hormones in Enhancing Antioxidant Defense Systems in Stressed Tomato (Solanum lycopersicum) Plants

by Paola Hernández-Carranza, Raúl Avila-Sosa, Obdulia Vera-López, Addí R. Navarro-Cruz, Héctor Ruíz-Espinosa, Irving I. Ruiz-López and Carlos E. Ochoa-Velasco

Plants 2023, 12(20), 3648; https://doi.org/10.3390/plants12203648 - 23 Oct 2023

Cited by 2 | Viewed by 2207

Abstract

Tomato is one of the most important fruits worldwide. It is widely consumed due to its sensory and nutritional attributes. However, like many other industrial crops, it is affected by biotic and abiotic stress factors, reducing its metabolic and physiological processes. Tomato plants [...] Read more.

Tomato is one of the most important fruits worldwide. It is widely consumed due to its sensory and nutritional attributes. However, like many other industrial crops, it is affected by biotic and abiotic stress factors, reducing its metabolic and physiological processes. Tomato plants possess different mechanisms of stress responses in which hormones have a pivotal role. They are responsible for a complex signaling network, where the antioxidant system (enzymatic and non-enzymatic antioxidants) is crucial for avoiding the excessive damage caused by stress factors. In this sense, it seems that hormones such as ethylene, auxins, brassinosteroids, and salicylic, jasmonic, abscisic, and gibberellic acids, play important roles in increasing antioxidant system and reducing oxidative damage caused by different stressors. Although several studies have been conducted on the stress factors, hormones, and primary metabolites of tomato plants, the effect of endogenous and/or exogenous hormones on the secondary metabolism is still poorly studied, which is paramount for tomato growing management and secondary metabolites production. Thus, this review offers an updated overview of both endogenous biosynthesis and exogenous hormone application in the antioxidant system of tomato plants as a response to biotic and abiotic stress factors. Full article

(This article belongs to the Special Issue Bioactive Secondary Metabolites in Plants: Biosynthesis, Regulation, and Function)

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25 pages, 4982 KiB

Open AccessArticle

Gamma-Aminobutyric Acid Supplementation Boosts the Phytohormonal Profile in ‘Candidatus Liberibacter asiaticus’-Infected Citrus

by Yasser Nehela and Nabil Killiny

Plants 2023, 12(20), 3647; https://doi.org/10.3390/plants12203647 - 22 Oct 2023

Cited by 2 | Viewed by 1511

Abstract

The devastating citrus disease, Huanglongbing (HLB), is associated with ‘Candidatus Liberibacter sp.’ and transmitted by citrus psyllids. Unfortunately, HLB has no known sustainable cure yet. Herein, we proposed γ-aminobutyric acid (GABA) as a potential eco-friendly therapeutic solution to HLB. Herein, we used [...] Read more.

The devastating citrus disease, Huanglongbing (HLB), is associated with ‘Candidatus Liberibacter sp.’ and transmitted by citrus psyllids. Unfortunately, HLB has no known sustainable cure yet. Herein, we proposed γ-aminobutyric acid (GABA) as a potential eco-friendly therapeutic solution to HLB. Herein, we used GC/MS-based targeted metabolomics combined with gene expression to investigate the role of GABA in citrus response against HLB and to better understand its relationship(s) with different phytohormones. GABA supplementation via root drench boosts the accumulation of endogenous GABA in the leaves of both healthy and ‘Ca. L. asiaticus’-infected trees. GABA accumulation benefits the activation of a multi-layered defensive system via modulating the phytohormone levels and regulating the expression of their biosynthesis genes and some pathogenesis-related proteins (PRs) in both healthy and ‘Ca. L. asiaticus’-infected plants. Moreover, our findings showed that GABA application stimulates auxin biosynthesis in ‘Ca. L. asiaticus’-infected plants via the activation of the indole-3-pyruvate (I3PA) pathway, not via the tryptamine (TAM)-dependent pathway, to enhance the growth of HLB-affected trees. Likewise, GABA accumulation was associated with the upregulation of SA biosynthesis genes, particularly the PAL-dependent route, resulting in higher SA levels that activated CsPR1, CsPR2, CsPR5, and CsWRKY70, which are prominent to activation of the SA-mediated pathway. Additionally, higher GABA levels were correlated with an enhanced JA profile and linked with both CsPR3 and CsPR4, which activates the JA-mediated pathway. Collectively, our findings suggest that exogenous GABA application might be a promising alternative and eco-friendly strategy that helps citrus trees battle HLB. Full article

(This article belongs to the Special Issue Disease Control Strategies in Citrus Plants)

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21 pages, 19271 KiB

Open AccessEditor’s ChoiceArticle

Morphological Characterization of Cannabis sativa L. Throughout Its Complete Life Cycle

by Mohsen Hesami, Marco Pepe and Andrew Maxwell Phineas Jones

Plants 2023, 12(20), 3646; https://doi.org/10.3390/plants12203646 - 22 Oct 2023

Cited by 7 | Viewed by 9982

Abstract

This study extensively characterizes the morphological characteristics, including the leaf morphology, plant structure, flower development, and trichome features throughout the entire life cycle of Cannabis sativa L. cv. White Widow. The developmental responses to photoperiodic variations were investigated from germination to mature plant [...] Read more.

This study extensively characterizes the morphological characteristics, including the leaf morphology, plant structure, flower development, and trichome features throughout the entire life cycle of Cannabis sativa L. cv. White Widow. The developmental responses to photoperiodic variations were investigated from germination to mature plant senescence. The leaf morphology showed a progression of complexity, beginning with serrations in the 1st true leaves, until the emergence of nine leaflets in the 6th true leaves, followed by a distinct shift to eight, then seven leaflets with the 14th and 15th true leaves, respectively. Thereafter, the leaf complexity decreased, culminating in the emergence of a single leaflet from the 25th node. The leaf area peaked with the 12th leaves, which coincided with a change from opposite to alternate phyllotaxy. The stipule development at nodes 5 and 6 signified the vegetative phase, followed by bract and solitary flower development emerging in nodes 7–12, signifying the reproductive phase. The subsequent induction of short-day photoperiod triggered the formation of apical inflorescence. Mature flowers displayed abundant glandular trichomes on perigonal bracts, with stigma color changing from whitish-yellow to reddish-brown. A pronounced increase in trichome density was evident, particularly on the abaxial bract surface, following the onset of flowering. The trichomes exhibited simultaneous growth in stalk length and glandular head diameter and pronounced shifts in color. Hermaphroditism occurred well after the general harvest date. This comprehensive study documents the intricate photoperiod-driven morphological changes throughout the complete lifecycle of Cannabis sativa L. cv. White Widow. The developmental responses characterized provide valuable insights for industrial and research applications. Full article

(This article belongs to the Special Issue Cannabis sativa: Advances in Biology and Cultivation)

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19 pages, 2934 KiB

Open AccessArticle

The Potential Genetic Effect for Yield and Foliar Disease Resistance in Faba Bean (Vicia faba L.) Assessed via Morphological and SCoT Markers

by Alaa A. Soliman, Manar I. Mousa, Abeer M. Mosalam, Zeinab E. Ghareeb, Shafik D. Ibrahim, Medhat Rehan, Haitian Yu and Yuhua He

Plants 2023, 12(20), 3645; https://doi.org/10.3390/plants12203645 - 22 Oct 2023

Cited by 1 | Viewed by 1353

Abstract

Faba bean is considered one of the most prominent grain legumes, with high protein content for human food consumption and livestock feed. The present study evaluated the nature of gene action and determined the genetic diversity among different populations of three crosses for [...] Read more.

Faba bean is considered one of the most prominent grain legumes, with high protein content for human food consumption and livestock feed. The present study evaluated the nature of gene action and determined the genetic diversity among different populations of three crosses for resistance to foliar diseases at the molecular level. Analysis of variance exposed significant differences among the generations for all measured traits. Both dominance and additive gene effects were essential, but dominance genes, for the most part, exhibited greater effects than additive ones. This indicates an essential role for dominant genes alongside the additives one in inheriting such traits. The third cross (Marina × Giza 40) gave desired significant and positive (additive × additive) values for the number of pods/plant, seeds/plant, and seed yield/plant, in addition to desirable negative values for chocolate spot and rust characteristics. Furthermore, assessing the lines under study using seven SCoT primers disclosed three bands with recorded molecular weights of 260, 207, and 178 bp, generated by SCoT-1, SCoT-4, and SCoT-7 primers, respectively. These bands exist in the resistant parent (Marina), which could be attributed to the high-disease-resistance phenotypes, and they are absent in the sensitive parent (Giza 40) and other putative sensitive lines. Based on the molecular profiles and the genetic similarity between parents and the selected lines, the highest similarity value (0.91) was detected between Marina genotype and BC₁, revealing a high foliar disease resistance. Meanwhile, Giza 40 (susceptible to foliar diseases) exhibited the maximum value (0.93) with F₂. Additionally, cluster analysis based on genetic relationships was performed, and a high level of correlation between the results of PCR-based SCoT analysis and the foliar disease reactions was observed in the field. Consequently, this study concluded that SCoT markers created reliable banding profiles for evaluating genetic polymorphism among faba bean lines, which could be a foundation for developing an efficient breeding program. Full article

(This article belongs to the Special Issue Legumes and Stressful Conditions)

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29 pages, 13029 KiB

Open AccessArticle

A Continuous Centennial Late Glacial-Early Holocene (15–10 cal kyr BP) Palynological Record from the Iberian Pyrenees and Regional Comparisons

by Valentí Rull, Arnau Blasco, Miguel Ángel Calero, Maarten Blaauw and Teresa Vegas-Vilarrúbia

Plants 2023, 12(20), 3644; https://doi.org/10.3390/plants12203644 - 22 Oct 2023

Cited by 2 | Viewed by 1839

Abstract

This paper presents the first continuous (gap-free) Late Glacial-Early Holocene (LGEH) pollen record for the Iberian Pyrenees resolved at centennial resolution. The main aims are (i) to provide a standard chronostratigraphic correlation framework, (ii) to unravel the relationships between vegetation shifts, climatic changes [...] Read more.

This paper presents the first continuous (gap-free) Late Glacial-Early Holocene (LGEH) pollen record for the Iberian Pyrenees resolved at centennial resolution. The main aims are (i) to provide a standard chronostratigraphic correlation framework, (ii) to unravel the relationships between vegetation shifts, climatic changes and fire, and (iii) to obtain a regional picture of LGEH vegetation for the Pyrenees and the surrounding lowlands. Seven pollen assemblage zones were obtained and correlated with the stadial/interstadial phases of the Greenland ice cores that serve as a global reference. Several well-dated datums were also derived for keystone individual taxa that are useful for correlation purposes. Four vegetation types were identified, two of them corresponding to conifer and deciduous forests (Cf, Df) and two representing open vegetation types (O1, O2) with no modern analogs, dominated by Artemisia-Poaceae and Saxifraga-Cichorioideae, respectively. Forests dominated during interstadial phases (Bølling/Allerød and Early Holocene), whereas O1 dominated during stadials (Oldest Dryas and Younger Dryas), with O2 being important only in the first half of the Younger Dryas. The use of pollen-independent proxies for temperature and moisture allowed the reconstruction of paleoclimatic trends and the responses of the four vegetation types defined. The most relevant observation in this sense was the finding of wet climates during the Younger Dryas, which challenges the traditional view of arid conditions for this phase on the basis of former pollen records. Fire incidence was low until the Early Holocene, when regional fires were exacerbated, probably due to the combination of higher temperatures and forest biomass accumulation. These results are compared with the pollen records available for the whole Pyrenean range and the surrounding lowlands within the framework of elevational, climatic and biogeographical gradients. Some potential future developments are suggested on the basis of the obtained results, with an emphasis on the reconsideration of the LGEH spatiotemporal moisture patterns and the comparison of the Pyrenees with other European ranges from different climatic and biogeographical regions. Full article

(This article belongs to the Special Issue Responses of Plants and Plant Communities to Environmental Changes in Mountain Areas)

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15 pages, 3826 KiB

Open AccessReview

Response Mechanisms of Woody Plants to High-Temperature Stress

by Chao Zhou, Shengjiang Wu, Chaochan Li, Wenxuan Quan and Anping Wang

Plants 2023, 12(20), 3643; https://doi.org/10.3390/plants12203643 - 22 Oct 2023

Cited by 2 | Viewed by 3063

Abstract

High-temperature stress is the main environmental stress that restricts the growth and development of woody plants, and the growth and development of woody plants are affected by high-temperature stress. The influence of high temperature on woody plants varies with the degree and duration [...] Read more.

High-temperature stress is the main environmental stress that restricts the growth and development of woody plants, and the growth and development of woody plants are affected by high-temperature stress. The influence of high temperature on woody plants varies with the degree and duration of the high temperature and the species of woody plants. Woody plants have the mechanism of adapting to high temperature, and the mechanism for activating tolerance in woody plants mainly counteracts the biochemical and physiological changes induced by stress by regulating osmotic adjustment substances, antioxidant enzyme activities and transcription control factors. Under high-temperature stress, woody plants ability to perceive high-temperature stimuli and initiate the appropriate physiological, biochemical and genomic changes is the key to determining the survival of woody plants. The gene expression induced by high-temperature stress also greatly improves tolerance. Changes in the morphological structure, physiology, biochemistry and genomics of woody plants are usually used as indicators of high-temperature tolerance. In this paper, the effects of high-temperature stress on seed germination, plant morphology and anatomical structure characteristics, physiological and biochemical indicators, genomics and other aspects of woody plants are reviewed, which provides a reference for the study of the heat-tolerance mechanism of woody plants. Full article

(This article belongs to the Topic Plant Responses to Environmental Stress)

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20 pages, 2670 KiB

Open AccessArticle

Comparing the Nutritional Needs of Two Solanaceae and One Cucurbitaceae Species Grown Hydroponically under the Same Cropping Conditions

by Eirini Xaxiri, Evangelos Darivakis, Ioannis Karavidas, Georgia Ntatsi and Dimitrios Savvas

Plants 2023, 12(20), 3642; https://doi.org/10.3390/plants12203642 - 22 Oct 2023

Cited by 2 | Viewed by 1889

Abstract

Switching over to closed-loop soilless culture systems, thus preventing pollution of water resources by nitrates and saving water and fertilizers, requires accurate estimations of the mean nutrient-to-water uptake ratios. To contribute to this objective, three fruit vegetable species (tomato, eggplant, cucumber) were grown [...] Read more.

Switching over to closed-loop soilless culture systems, thus preventing pollution of water resources by nitrates and saving water and fertilizers, requires accurate estimations of the mean nutrient-to-water uptake ratios. To contribute to this objective, three fruit vegetable species (tomato, eggplant, cucumber) were grown hydroponically in a floating system under identical cropping conditions to quantify species differences in nutrient uptake. The composition of the nutrient solution used to feed the crops was identical for all species. The total water consumption and the concentrations of most nutrients (K, Ca, Mg, N, P, Fe, Mn, Zn, Cu, B) in the nutrient solution and the plant tissues were measured at crop establishment and at two different crop developmental stages. The obtained data were used to determine the uptake concentrations (UCs) using two mass balance models, one based on nutrient removal from the nutrient solution and a second based on nutrient recovery in the plant tissues. The experiment was conducted in the spring–summer season. The results revealed that the nutrient uptake concentrations were substantially different between species for all nutrients except for N, while there were also significant interactions between the two methods used for their estimation of some nutrients. Thus, the UCs of N, P, Ca, and some micronutrients were significantly higher when its estimation was based on the removal of nutrients from the nutrient solution compared to recovery from plant tissues, presumably because with the first method, losses due to denitrification or precipitation could not be separated from those of plant uptake. The comparison of the three greenhouse vegetables revealed a similar UC for nitrogen, while cucumber generally showed significantly lower UCs for P and for the micronutrients Fe, Zn, and Cu at both cropping stages compared to the two Solanaceae species. The obtained results can be used to precisely adjust the nutrient supply in closed-loop soilless cultivations to the plant uptake thus avoiding both depletion and accumulation of nutrients in the root environment. Full article

(This article belongs to the Special Issue Soil Fertility, Plant Nutrition and Nutrient Management)

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19 pages, 2272 KiB

Open AccessArticle

Suspension Cell Culture of Polyscias fruticosa (L.) Harms in Bubble-Type Bioreactors—Growth Characteristics, Triterpene Glycosides Accumulation and Biological Activity

by Maria V. Titova, Dmitry V. Kochkin, Elena S. Sukhanova, Elena N. Gorshkova, Tatiana M. Tyurina, Igor M. Ivanov, Maria K. Lunkova, Elena V. Tsvetkova, Anastasia Orlova, Elena V. Popova and Alexander M. Nosov

Plants 2023, 12(20), 3641; https://doi.org/10.3390/plants12203641 - 22 Oct 2023

Cited by 1 | Viewed by 2160

Abstract

Polyscias fruticosa (L.) Harms, or Ming aralia, is a medicinal plant of the Araliaceae family, which is highly valued for its antitoxic, anti-inflammatory, analgesic, antibacterial, anti-asthmatic, adaptogenic, and other properties. The plant can be potentially used to treat diabetes and its complications, ischemic [...] Read more.

Polyscias fruticosa (L.) Harms, or Ming aralia, is a medicinal plant of the Araliaceae family, which is highly valued for its antitoxic, anti-inflammatory, analgesic, antibacterial, anti-asthmatic, adaptogenic, and other properties. The plant can be potentially used to treat diabetes and its complications, ischemic brain damage, and Parkinson’s disease. Triterpene glycosides of the oleanane type, such as 3-O-[β-D-glucopyranosyl-(1→4)-β-D-glucuronopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (PFS), ladyginoside A, and polysciosides A-H, are mainly responsible for biological activities of this species. In this study, cultivation of the cell suspension of P. fruticosa in 20 L bubble-type bioreactors was attempted as a sustainable method for cell biomass production of this valuable species and an alternative to overexploitation of wild plant resources. Cell suspension cultivated in bioreactors under a semi-continuous regime demonstrated satisfactory growth with a specific growth rate of 0.11 day⁻¹, productivity of 0.32 g (L · day)^−1, and an economic coefficient of 0.16 but slightly lower maximum biomass accumulation (~6.8 g L⁻¹) compared to flask culture (~8.2 g L⁻¹). Triterpene glycosides PFS (0.91 mg gDW⁻¹) and ladyginoside A (0.77 mg gDW⁻¹) were detected in bioreactor-produced cell biomass in higher concentrations compared to cells grown in flasks (0.50 and 0.22 mg gDW⁻¹, respectively). In antibacterial tests, the minimum inhibitory concentrations (MICs) of cell biomass extracts against the most common pathogens Staphylococcus aureus, methicillin-resistant strain MRSA, Pseudomonas aeruginosa, and Escherichia coli varied within 250–2000 µg mL⁻¹ which was higher compared to extracts of greenhouse plant leaves (MIC = 4000 µg mL⁻¹). Cell biomass extracts also exhibited antioxidant activity, as confirmed by DPPH and TEAC assays. Our results suggest that bioreactor cultivation of P. fruticosa suspension cell culture may be a perspective method for the sustainable biomass production of this species. Full article

(This article belongs to the Special Issue Production of Plant Secondary Metabolites Using Plant Tissue Culture and Bioreactor Culture Techniques)

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16 pages, 3000 KiB

Open AccessArticle

Changes in Nutrient Components and Digestive Enzymatic Inhibition Activities in Soy Leaves by Ethephon Treatment

by Ji Ho Lee, Du Yong Cho, Kyeong Jin Jang, Jong Bin Jeong, Ga Young Lee, Mu Yeun Jang, Ki Ho Son, Jin Hwan Lee, Hee Yul Lee and Kye Man Cho

Plants 2023, 12(20), 3640; https://doi.org/10.3390/plants12203640 - 21 Oct 2023

Viewed by 1497

Abstract

In this study, the high isoflavone-enriched soy leaves (IESLs) were manufactured by treating with the chemical inducer ethephon, a plant growth regulator, to confirm changes in the properties of soy leaves (SLs), which are underutilized. Ethephon treatment concentrations consisted of 0 (SL1), 150 [...] Read more.

In this study, the high isoflavone-enriched soy leaves (IESLs) were manufactured by treating with the chemical inducer ethephon, a plant growth regulator, to confirm changes in the properties of soy leaves (SLs), which are underutilized. Ethephon treatment concentrations consisted of 0 (SL1), 150 (SL2), and 300 (SL3) μg/mL. The composition analysis and physiological activity were conducted according to the ethephon treatment concentration of SLs. There was no significant difference in the proximate composition and fatty acids, except for an increase with increasing ethephon treatment concentrations. Depending on the ethephon treatment concentration, free amino acids increased to 1413.0, 1569.8, and 2100.4 mg/100 g, and water-soluble vitamins increased to 246.7, 244.7, and 501.6 mg/100 g. In particular, the functional substance isoflavone increased significantly to 1430.11, 7806.42, and 14,968.00 μg/g. Through this study, it was confirmed that the nutritional components and isoflavones of SLs increased according to the ethephon treatment concentration, a chemical inducer treatment agent. This can be used as a high-value-added biosubstance for raw materials for functional foods, cosmetics, and for natural drugs. Full article

(This article belongs to the Section Plant Nutrition)

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12 pages, 2178 KiB

Open AccessArticle

Identification of Morphogenesis-Related NDR Kinase Signaling Network and Its Regulation on Cold Tolerance in Maize

by Ran Tian, Sidi Xie, Junjie Zhang, Hanmei Liu, Yangping Li, Yufeng Hu, Yubi Huang and Yinghong Liu

Plants 2023, 12(20), 3639; https://doi.org/10.3390/plants12203639 - 21 Oct 2023

Cited by 1 | Viewed by 1105

Abstract

The MOR (Morphogenesis-related NDR kinase) signaling network, initially identified in yeast, exhibits evolutionary conservation across eukaryotes and plays indispensable roles in the normal growth and development of these organisms. However, the functional role of this network and its associated genes in maize ( [...] Read more.

The MOR (Morphogenesis-related NDR kinase) signaling network, initially identified in yeast, exhibits evolutionary conservation across eukaryotes and plays indispensable roles in the normal growth and development of these organisms. However, the functional role of this network and its associated genes in maize (Zea mays) has remained elusive until now. In this study, we identified a total of 19 maize MOR signaling network genes, and subsequent co-expression analysis revealed that 12 of these genes exhibited stronger associations with each other, suggesting their potential collective regulation of maize growth and development. Further analysis revealed significant co-expression between genes involved in the MOR signaling network and several genes related to cold tolerance. All MOR signaling network genes exhibited significant co-expression with COLD1 (Chilling tolerance divergence1), a pivotal gene involved in the perception of cold stimuli, suggesting that COLD1 may directly transmit cold stress signals to MOR signaling network genes subsequent to the detection of a cold stimulus. The findings indicated that the MOR signaling network may play a crucial role in modulating cold tolerance in maize by establishing an intricate relationship with key cold tolerance genes, such as COLD1. Under low-temperature stress, the expression levels of certain MOR signaling network genes were influenced, with a significant up-regulation observed in Zm00001d010720 and a notable down-regulation observed in Zm00001d049496, indicating that cold stress regulated the MOR signaling network. We identified and analyzed a mutant of Zm00001d010720, which showed a higher sensitivity to cold stress, thereby implicating its involvement in the regulation of cold stress in maize. These findings suggested that the relevant components of the MOR signaling network are also conserved in maize and this signaling network plays a vital role in modulating the cold tolerance of maize. This study offered valuable genetic resources for enhancing the cold tolerance of maize. Full article

(This article belongs to the Special Issue Abiotic Stress of Crops: Molecular Genetics and Genomics)

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14 pages, 2548 KiB

Open AccessArticle

Hormonal Interplay Leading to Black Knot Disease Establishment and Progression in Plums

by Ranjeet Shinde, Murali-Mohan Ayyanath, Mukund Shukla, Walid El Kayal, Praveen Saxena and Jayasankar Subramanian

Plants 2023, 12(20), 3638; https://doi.org/10.3390/plants12203638 - 21 Oct 2023

Cited by 1 | Viewed by 1351

Abstract

Black Knot (BK) is a deadly disease of European (Prunus domestics) and Japanese (Prunus salicina) plums caused by the hemibiotrophic fungus Apiosporina morbosa. After infection, the appearance of warty black knots indicates a phytohormonal imbalance in infected tissues. [...] Read more.

Black Knot (BK) is a deadly disease of European (Prunus domestics) and Japanese (Prunus salicina) plums caused by the hemibiotrophic fungus Apiosporina morbosa. After infection, the appearance of warty black knots indicates a phytohormonal imbalance in infected tissues. Based on this hypothesis, we quantified phytohormones such as indole-3-acetic acid, tryptophan, indoleamines (N-acetylserotonin, serotonin, and melatonin), and cytokinins (zeatin, 6-benzyladenine, and 2-isopentenyladenine) in temporally collected tissues of susceptible and resistant genotypes belonging to European and Japanese plums during of BK progression. The results suggested auxin-cytokinins interplay driven by A. morbosa appears to be vital in disease progression by hampering the plant defense system. Taken together, our results indicate the possibility of using the phytohormone profile as a biomarker for BK resistance in plums. Full article

(This article belongs to the Special Issue Advances in Plant-Fungal Pathogen Interaction)

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14 pages, 7026 KiB

Open AccessArticle

The Cytokinins BAP and 2-iP Modulate Different Molecular Mechanisms on Shoot Proliferation and Root Development in Lemongrass (Cymbopogon citratus)

by María del Rosario Cárdenas-Aquino, Alberto Camas-Reyes, Eliana Valencia-Lozano, Lorena López-Sánchez, Agustino Martínez-Antonio and José Luis Cabrera-Ponce

Plants 2023, 12(20), 3637; https://doi.org/10.3390/plants12203637 - 21 Oct 2023

Cited by 4 | Viewed by 2101

Abstract

The known activities of cytokinins (CKs) are promoting shoot multiplication, root growth inhibition, and delaying senescence. 6-Benzylaminopurine (BAP) has been the most effective CK to induce shoot proliferation in cereal and grasses. Previously, we reported that in lemongrass (Cymbopogon citratus) micropropagation, [...] Read more.

The known activities of cytokinins (CKs) are promoting shoot multiplication, root growth inhibition, and delaying senescence. 6-Benzylaminopurine (BAP) has been the most effective CK to induce shoot proliferation in cereal and grasses. Previously, we reported that in lemongrass (Cymbopogon citratus) micropropagation, BAP 10 µM induces high shoot proliferation, while the natural CK 6-(γ,γ-Dimethylallylamino)purine (2-iP) 10 µM shows less pronounced effects and developed rooting. To understand the molecular mechanisms involved, we perform a protein–protein interaction (PPI) network based on the genes of Brachypodium distachyon involved in shoot proliferation/repression, cell cycle, stem cell maintenance, auxin response factors, and CK signaling to analyze the molecular mechanisms in BAP versus 2-iP plants. A different pattern of gene expression was observed between BAP- versus 2-iP-treated plants. In shoots derived from BAP, we found upregulated genes that have already been demonstrated to be involved in de novo shoot proliferation development in several plant species; CK receptors (AHK3, ARR1), stem cell maintenance (STM, REV and CLV3), cell cycle regulation (CDKA-CYCD3 complex), as well as the auxin response factor (ARF5) and CK metabolism (CKX1). In contrast, in the 2-iP culture medium, there was an upregulation of genes involved in shoot repression (BRC1, MAX3), ARR4, a type A-response regulator (RR), and auxin metabolism (SHY2). Full article

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15 pages, 3267 KiB

Open AccessArticle

Bacillus velezensis ZN-S10 Reforms the Rhizosphere Microbial Community and Enhances Tomato Resistance to TPN

by Enlei Chen, Shufen Chao, Bin Shi, Lu Liu, Mengli Chen, Yongli Zheng, Xiaoxiao Feng and Huiming Wu

Plants 2023, 12(20), 3636; https://doi.org/10.3390/plants12203636 - 21 Oct 2023

Cited by 3 | Viewed by 1475

Abstract

Tomato pith necrosis (TPN) is a highly destructive disease caused by species of the Pseudomonas genus and other bacteria, resulting in a significant reduction in tomato yield. Members of the genus Bacillus are beneficial microorganisms extensively studied in the rhizosphere. However, in most [...] Read more.

Tomato pith necrosis (TPN) is a highly destructive disease caused by species of the Pseudomonas genus and other bacteria, resulting in a significant reduction in tomato yield. Members of the genus Bacillus are beneficial microorganisms extensively studied in the rhizosphere. However, in most cases, the potential of Bacillus members in controlling TPN and their impact on the rhizosphere microbial composition remain rarely studied. In this study, Bacillus velezensis ZN-S10 significantly inhibited the growth of Pseudomonas viridiflava ZJUP0398-2, and ZN-S10 controlled TPN with control efficacies of 60.31%. P. viridiflava ZJUP0398-2 significantly altered the richness and diversity of the tomato rhizobacterial community, but pre-inoculation with ZN-S10 mitigated these changes. The correlation analysis revealed that ZN-S10 maybe inhibits the growth of nitrogen-fixing bacteria and recruits beneficial bacterial communities associated with disease resistance, thereby suppressing the occurrence of diseases. In summary, the comparative analysis of the rhizosphere microbiome was conducted to explore the impact of ZN-S10 on the composition of rhizosphere microorganisms in the presence of pathogenic bacteria, aiming to provide insights for further research and the development of scientific and eco-friendly control strategies for this disease. Full article

(This article belongs to the Special Issue Plant-Microbe Interactions 2023)

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20 pages, 5176 KiB

Open AccessEditor’s ChoiceArticle

Edible Fruits from the Ecuadorian Amazon: Ethnobotany, Physicochemical Characteristics, and Bioactive Components

by Maritza Sánchez-Capa, Mireia Corell González and Carlos Mestanza-Ramón

Plants 2023, 12(20), 3635; https://doi.org/10.3390/plants12203635 - 21 Oct 2023

Cited by 4 | Viewed by 2901

Abstract

In the Ecuadorian Amazon region, there are various types of edible fruits that have distinct qualities and benefits. Understanding the uses, properties, and functions of these fruits is important for researching products that are only available in local markets. This review aims to [...] Read more.

In the Ecuadorian Amazon region, there are various types of edible fruits that have distinct qualities and benefits. Understanding the uses, properties, and functions of these fruits is important for researching products that are only available in local markets. This review aims to gather and summarize the existing scientific literature on the ethnobotany, physicochemical composition, and bioactive compounds of these native fruits to highlight the potential of the region’s underutilized biodiversity. A systematic review was carried out following the PRISMA methodology, utilizing databases such as Web of Science, Scopus, Pubmed, Redalyc, and SciELO up to August 2023. The research identified 55 edible fruits from the Ecuadorian Amazon and reported their ethnobotanical information. The most common uses were fresh fruit consumption, preparation of typical food, and medicine. Additionally, nine native edible fruits were described for their physicochemical characteristics and bioactive components: Aphandra natalia (Balslev and Henderson) Barfod; Eugenia stipitate McVaugh; Gustavia macarenensis Philipson; Mauritia flexuosa L.f; Myrciaria dubia (Kunth) McVaugh; Oenocarpus bataua Mart; Plukenetia volubilis L.; Pouteria caimito (Ruiz and Pav.) Radlk.; and Solanum quitoense Lam. The analyzed Amazonian fruits contained bioactive compounds such as total polyphenols, flavonoids, carotenoids, and anthocyanins. This information highlights their potential as functional foods and the need for further research on underutilized crops. Full article

(This article belongs to the Special Issue Medicinal Plants and Natural Products in South America)

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15 pages, 6794 KiB

Open AccessArticle

Identification of Crucial Genes and Regulatory Pathways in Alfalfa against Fusarium Root Rot

by Shengze Wang, Haibin Han, Bo Zhang, Le Wang, Jie Wu, Zhengqiang Chen, Kejian Lin, Jianjun Hao, Ruifang Jia and Yuanyuan Zhang

Plants 2023, 12(20), 3634; https://doi.org/10.3390/plants12203634 - 21 Oct 2023

Cited by 2 | Viewed by 1498

Abstract

Fusarium root rot, caused by Fusarium spp. in alfalfa (Medicago sativa L.), adversely impacts alfalfa by diminishing plant quality and yield, resulting in substantial losses within the industry. The most effective strategy for controlling alfalfa Fusarium root rot is planting disease-resistant varieties. [...] Read more.

Fusarium root rot, caused by Fusarium spp. in alfalfa (Medicago sativa L.), adversely impacts alfalfa by diminishing plant quality and yield, resulting in substantial losses within the industry. The most effective strategy for controlling alfalfa Fusarium root rot is planting disease-resistant varieties. Therefore, gaining a comprehensive understanding of the mechanisms underlying alfalfa’s resistance to Fusarium root rot is imperative. In this study, we observed the infection process on alfalfa seedling roots infected by Fusarium acuminatum strain HM29-05, which is labeled with green fluorescent protein (GFP). Two alfalfa varieties, namely, the resistant ‘Kangsai’ and the susceptible ‘Zhongmu No. 1’, were examined to assess various physiological and biochemical activities at 0, 2, and 3 days post inoculation (dpi). Transcriptome sequencing of the inoculated resistant and susceptible alfalfa varieties were conducted, and the potential functions and signaling pathways of differentially expressed genes (DEGs) were analyzed through gene ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Meanwhile, a DEG co-expression network was constructed though the weighted gene correlation network analysis (WGCNA) algorithm. Our results revealed significant alterations in soluble sugar, soluble protein, and malondialdehyde (MDA) contents in both the ‘Kangsai’ and ‘Zhongmu No. 1’ varieties following the inoculation of F. acuminatum. WGCNA analysis showed the involvement of various enzyme and transcription factor families related to plant growth and disease resistance, including cytochrome P450, MYB, ERF, NAC, and bZIP. These findings not only provided valuable data for further verification of gene functions but also served as a reference for the deeper explorations between plants and pathogens. Full article

(This article belongs to the Special Issue Molecular Mechanisms of Plant Defense against Fungal Pathogens)

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32 pages, 2466 KiB

Open AccessEditor’s ChoiceReview

The Past, Present, and Future of Wheat Dwarf Virus Management—A Review

by Anne-Kathrin Pfrieme, Torsten Will, Klaus Pillen and Andreas Stahl

Plants 2023, 12(20), 3633; https://doi.org/10.3390/plants12203633 - 20 Oct 2023

Cited by 3 | Viewed by 2389

Abstract

Wheat dwarf disease (WDD) is an important disease of monocotyledonous species, including economically important cereals. The causative pathogen, wheat dwarf virus (WDV), is persistently transmitted mainly by the leafhopper Psammotettix alienus and can lead to high yield losses. Due to climate change, the [...] Read more.

Wheat dwarf disease (WDD) is an important disease of monocotyledonous species, including economically important cereals. The causative pathogen, wheat dwarf virus (WDV), is persistently transmitted mainly by the leafhopper Psammotettix alienus and can lead to high yield losses. Due to climate change, the periods of vector activity increased, and the vectors have spread to new habitats, leading to an increased importance of WDV in large parts of Europe. In the light of integrated pest management, cultivation practices and the use of resistant/tolerant host plants are currently the only effective methods to control WDV. However, knowledge of the pathosystem and epidemiology of WDD is limited, and the few known sources of genetic tolerance indicate that further research is needed. Considering the economic importance of WDD and its likely increasing relevance in the coming decades, this study provides a comprehensive compilation of knowledge on the most important aspects with information on the causal virus, its vector, symptoms, host range, and control strategies. In addition, the current status of genetic and breeding efforts to control and manage this disease in wheat will be discussed, as this is crucial to effectively manage the disease under changing environmental conditions and minimize impending yield losses. Full article

(This article belongs to the Special Issue Genetic Basis of Yield and Yield Stability in Major Crops)

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Plants, Volume 12, Issue 20 (October-2 2023) – 147 articles

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