Plants

25 pages, 8577 KiB

Open AccessEditor’s ChoiceArticle

Morphological and Physiological Indicators and Transcriptome Analyses Reveal the Mechanism of Selenium Multilevel Mitigation of Cadmium Damage in Brassica juncea

by Linling Li, Shiyan Wang, Shuai Wu, Shen Rao, Li Li, Shuiyuan Cheng and Hua Cheng

Plants 2023, 12(8), 1583; https://doi.org/10.3390/plants12081583 - 7 Apr 2023

Cited by 13 | Viewed by 2676

Abstract

Cadmium (Cd) is a common agricultural soil pollutant, which does serious harm to the environment and the human body. In this study, Brassica juncea was treated with different concentrations of CdCl₂ and Na₂SeO₃. Then, physiological indexes and transcriptome [...] Read more.

Cadmium (Cd) is a common agricultural soil pollutant, which does serious harm to the environment and the human body. In this study, Brassica juncea was treated with different concentrations of CdCl₂ and Na₂SeO₃. Then, physiological indexes and transcriptome were measured to reveal the mechanisms by which Se reduces the inhibition and toxicity of Cd in B. juncea. The results showed that Se alleviated the inhibitive Cd effects on seedling biomass, root length, and chlorophyll, and promoted the adsorption of Cd by pectin and lignin in the root cell wall (CW). Se also alleviated the oxidative stress induced by Cd, and reduced the content of MDA in cells. As a result, SeCys and SeMet alleviated the transport of Cd to the shoots. Transcriptome data showed that the bivalent cation transporter MPP and ABCC subfamily participated in the separation of Cd in vacuoles, CAL1 was related to the chelation of Cd in the cytoplasm of cells, and ZIP transporter 4 reduced the transport of Cd to the shoots. These results indicated that Se alleviated the damage of Cd in plants and decreased its transport to the shoots by improving the antioxidant system, enhancing the ability of the CW to adsorb Cd, reducing the activity of Cd transporters, and chelating Cd. Full article

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

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16 pages, 2432 KiB

Open AccessEditor’s ChoiceArticle

Essential Oil of Lavandula officinalis: Chemical Composition and Antibacterial Activities

by Khaoula Diass, Mohammed Merzouki, Kaoutar Elfazazi, Hanane Azzouzi, Allal Challioui, Khalil Azzaoui, Belkheir Hammouti, Rachid Touzani, Flore Depeint, Alicia Ayerdi Gotor and Larbi Rhazi

Plants 2023, 12(7), 1571; https://doi.org/10.3390/plants12071571 - 6 Apr 2023

Cited by 48 | Viewed by 8932

Abstract

The purpose of this study was to determine the chemical composition of the essential oil of Lavandula officinalis from Morocco using the GC-MS technique and assess the antibacterial effects against seven pathogenic bacteria strains isolated from the food origins of Salmonella infantis, [...] Read more.

The purpose of this study was to determine the chemical composition of the essential oil of Lavandula officinalis from Morocco using the GC-MS technique and assess the antibacterial effects against seven pathogenic bacteria strains isolated from the food origins of Salmonella infantis, Salmonella kentucky, Salmonella newport, three serotypes of Escherichia coli (O114H8K11, O127K88ac, O127H40K11) and Klebsiella. Tests of sensitivity were carried out on a solid surface using the Disc Diffusion Method. Results showed that E. coli and S.newport were sensitive to Lavandula officinalis essential oil. Minimum inhibitory concentrations (MIC) were determined using the method of agar dilution. The antibacterial results showed that four strains (three serotypes of E. coli, and S. newport) were remarkedly sensitive to Lavandula officinalis essential oil, giving MIC values of 88.7 µg/mL and 177.5 µg/mL. The molecular docking of the main oil products with the E. coli target protein 1VLY, showed that eucalyptol and linalyl acetate bind efficiently with the active site of the target protein. In particular, eucalyptol showed a higher activity than gentamicin used as positive control with a binding energy of −5.72 kcal/mol and −5.55 kcal/mol, respectively. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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15 pages, 4575 KiB

Open AccessEditor’s ChoiceArticle

Plant Growth and Soil Water Content Changes under Different Inter-Row Soil Management Methods in a Sloping Vineyard

by Ágota Horel and Tibor Zsigmond

Plants 2023, 12(7), 1549; https://doi.org/10.3390/plants12071549 - 4 Apr 2023

Cited by 12 | Viewed by 4971

Abstract

The main objective of this study was to investigate soil–plant–water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed sloping vineyards. The following three different soil management applications were studied: tilled (T), cover crops (CC), [...] Read more.

The main objective of this study was to investigate soil–plant–water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed sloping vineyards. The following three different soil management applications were studied: tilled (T), cover crops (CC), and permanent grass (NT) inter-rows. We measured SWCs within the row and between rows of vines. Each investigated row utilized 7 to 10 measurement points along the slope. Topsoil SWC and temperature, leaf NDVI and chlorophyll concentrations and leaf area index (LAI) were measured every two weeks over the vegetation period (May to November) using handheld instruments. We found that management method and slope position can significantly affect the soil’s physical and chemical properties, such as clay or soil organic carbon contents. Cover crops in the inter-row significantly reduced average SWC. The in-row average topsoil SWCs and temperatures were lower in all study sites compared to the values measured in between rows. Significantly higher SWCs were observed for the upper points compared to the lower ones for CC and T treatments (58.0 and 60.9%, respectively), while the opposite was noted for NT. Grassed inter-row grapevines had significantly lower leaf chlorophyll content than the other inter-row managed sites (p < 0.001). The highest average leaf chlorophyll contents were observed in the T vineyard (16.89 CCI). Based on slope positions, the most distinguishable difference was observed for the CC: 27.7% higher chlorophyll values were observed at the top of the slope compared to the grapevine leaves at the bottom of the slope (p < 0.01). The leaf NDVI values were not as profoundly influenced by slope position in the vineyard as the chlorophyll values were. For overall LAI values, the T treatment had significantly lower values compared to NT and CC (p < 0.001). Moderate correlations were observed between NDVI and LAI and soil nitrogen and carbon content. In general, we found that both inter-row management and slope position can significantly influence soil parameters and affect plant growth, and consequently can accelerate plant stress under sub-optimal environmental conditions such as prolonged drought. Full article

(This article belongs to the Special Issue Soil-Plant-Water System and Interactions)

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17 pages, 1082 KiB

Open AccessEditor’s ChoiceReview

Shade-Induced Leaf Senescence in Plants

by Zhuang Li, Tao Zhao, Jun Liu, Hongyu Li and Bin Liu

Plants 2023, 12(7), 1550; https://doi.org/10.3390/plants12071550 - 4 Apr 2023

Cited by 16 | Viewed by 4884

Abstract

Leaf senescence is a vital developmental process that involves the orderly breakdown of macromolecules to transfer nutrients from mature leaves to emerging and reproductive organs. This process is essential for a plant’s overall fitness. Multiple internal and external factors, such as leaf age, [...] Read more.

Leaf senescence is a vital developmental process that involves the orderly breakdown of macromolecules to transfer nutrients from mature leaves to emerging and reproductive organs. This process is essential for a plant’s overall fitness. Multiple internal and external factors, such as leaf age, plant hormones, stresses, and light environment, regulate the onset and progression of leaf senescence. When plants grow close to each other or are shaded, it results in significant alterations in light quantity and quality, such as a decrease in photosynthetically active radiation (PAR), a drop in red/far-red light ratios, and a reduction in blue light fluence rate, which triggers premature leaf senescence. Recently, studies have identified various components involved in light, phytohormone, and other signaling pathways that regulate the leaf senescence process in response to shade. This review summarizes the current knowledge on the molecular mechanisms that control leaf senescence induced by shade. Full article

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14 pages, 7530 KiB

Open AccessEditor’s ChoiceArticle

Fingerprinting of Plum (Prunus domestica) Genotypes in Lithuania Using SSR Markers

by Raminta Antanynienė, Jūratė Bronė Šikšnianienė, Vidmantas Stanys and Birutė Frercks

Plants 2023, 12(7), 1538; https://doi.org/10.3390/plants12071538 - 3 Apr 2023

Cited by 10 | Viewed by 2309

Abstract

This study’s aim was to evaluate the genetic diversity of European plum (Prunus domestica) cultivars and hybrids in Lithuania using SSR markers. In total, 107 plum genotypes (including 68 European plum cultivars and 39 hybrids) from the genetic resources collection of [...] Read more.

This study’s aim was to evaluate the genetic diversity of European plum (Prunus domestica) cultivars and hybrids in Lithuania using SSR markers. In total, 107 plum genotypes (including 68 European plum cultivars and 39 hybrids) from the genetic resources collection of the Institute of Horticulture of the Lithuanian Research Centre for Agriculture and Forestry (LRCAF IH) were evaluated using nine microsatellite markers (SSRs) previously published and suggested by the European Cooperative Programme for Plant Genetic Resources (ECPGR). Up to six alleles per locus with each primer pair were generated for some genotypes due to the hexaploidy of plums. The number of alleles in each primer ranged from 18 to 30, with an average of 24.33. The highest number of alleles was generated with the PacA33 primer pair (30). The most informative primer, according to the PIC value, was BPPCT007. Sixty-two unique alleles (representing 39.5% of all polymorphic alleles) have been detected in the plum germplasm developed in Lithuania. According to UPGMA cluster analysis, 58 European plum genotypes were separated into eight groups without any relation to fruit color or shape. By genetic diversity (UPGMA) and structure (Bayesian) analysis, European plum hybrids were grouped into clusters according to their pedigree. Full article

(This article belongs to the Special Issue Selected Papers from the 3rd International Conference on Scientific Actualities and Innovations in Horticulture (SAIH2022))

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17 pages, 9431 KiB

Open AccessEditor’s ChoiceArticle

Bioinformatics and Expression Analysis of the Chitinase Genes in Strawberry (Fragaria vesca) and Functional Study of FvChi-14

by Tiannan He, Jianshuai Fan, Gaozhen Jiao, Yuhan Liu, Qimeng Zhang, Ning Luo, Bilal Ahmad, Qingxi Chen and Zhifeng Wen

Plants 2023, 12(7), 1543; https://doi.org/10.3390/plants12071543 - 3 Apr 2023

Cited by 8 | Viewed by 3010

Abstract

Plant chitinases (EC 3.2.1.14) are pathogenesis-related (PR) proteins and are well studied in many plant species. However, little is known about the genomic organization and expression of chitinase genes in strawberries (Fragaria vesca). Here, 23 FvChi genes were identified in the [...] Read more.

Plant chitinases (EC 3.2.1.14) are pathogenesis-related (PR) proteins and are well studied in many plant species. However, little is known about the genomic organization and expression of chitinase genes in strawberries (Fragaria vesca). Here, 23 FvChi genes were identified in the genome of strawberry (F. vesca) and divided into GH18 and GH19 subfamilies based on phylogenetic relationships. A detailed bioinformatics analysis of the FvChi genes was performed, including gene physicochemical properties, chromosomal location, exon–intron distribution, domain arrangement, and subcellular localization. Twenty-two FvChi genes showed upregulation after Colletotrichum gloeosporioides infection. Following the exogenous application of SA, FvChi-3, 4, and 5 showed significant changes in expression. The ectopic expression of FvChi-14 in Arabidopsis thaliana increased resistance to C. higginsianum via controlling the SA and JA signaling pathway genes (AtPR1, AtICS1, AtPDF1.2, and AtLOX3). The FvChi-14 protein location was predicted in the cell wall or extracellular matrix. We speculate that FvChi-14 is involved in disease resistance by regulating the SA and JA signaling pathways. The findings of this study provide a theoretical reference for the functional studies of FvChi genes and new candidates for strawberry stress resistance breeding programs. Full article

(This article belongs to the Section Horticultural Science and Ornamental Plants)

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15 pages, 2562 KiB

Open AccessEditor’s ChoiceArticle

Micropropagation of Endemic Endangered Taxa of the Italian Flora: Adenostyles alpina subsp. macrocephala (Asteraceae), as a Case Study

by Valeria Gianguzzi, Giulio Barone, Emilio Di Gristina, Francesco Sottile and Gianniantonio Domina

Plants 2023, 12(7), 1530; https://doi.org/10.3390/plants12071530 - 1 Apr 2023

Cited by 6 | Viewed by 2433

Abstract

The conservation of endangered, rare, and endemic plant species is based on in situ and ex situ conservation strategies. When in situ conservation alone is not sufficient to guarantee the survival of the species, ex situ techniques are adopted in support. This study [...] Read more.

The conservation of endangered, rare, and endemic plant species is based on in situ and ex situ conservation strategies. When in situ conservation alone is not sufficient to guarantee the survival of the species, ex situ techniques are adopted in support. This study aimed to develop an efficient micropropagation protocol for Adenostyles by evaluating the effect of different plant growth regulators on leaf explants. Adenostyles alpina subsp. macrocephala (Asterace) is a perennial herbaceous plant endemic to Calabria (Southern Italy). The genus Adenostyles includes three species confined to the mountains of the Mediterranean and southern Europe. For callus induction, media supplemented with different concentrations of Benzylaminopurine (BAP) (0.5, 1, 2, and 3 mg L⁻¹), Naphthaleneacetic Acid (NAA) (1 mg L⁻¹), and 2,4-Dichlorophenoxyacetic Acid (2,4-D) (1 mg L⁻¹) were tested. Shoot regeneration and proliferation were obtained in media supplemented with BAP (1, 2, and 3 mg L⁻¹) and NAA (1 mg L⁻¹). Root induction was obtained in media supplemented with IBA (0.25, 0.50, and 1 mg L⁻¹) and NAA (0.25, 0.50, and 1 mg L⁻¹). Statistically significant differences in callus induction and shoot regeneration were observed between the various media tested. The medium containing Murashige and Skoog (MS) supplemented with 3 mg L⁻¹ of BAP and 1 mg L⁻¹ of NAA showed the highest percentage of callus induction and increased shoot regeneration. The regenerated shoots showed more effective root induction in the hormone-free MS medium and in the presence of Indole-3-Butyric Acid (IBA) at concentrations of 0.25, 0.50, and 1 mg L⁻¹. These results can be used as a basis for the preparation of a micropropagation protocol for different taxa of Adenostyles, as well as other species of Asteraceae specialized to the Mediterranean mountain habitat. Full article

(This article belongs to the Special Issue Micropropagation and Cryopreservation of Plants)

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45 pages, 2749 KiB

Open AccessEditor’s ChoiceReview

Physicochemical, Nutritional, and Medicinal Properties of Opuntia ficus-indica (L.) Mill. and Its Main Agro-Industrial Use: A Review

by Mariana Martins, Maria H. Ribeiro and Cristina M. M. Almeida

Plants 2023, 12(7), 1512; https://doi.org/10.3390/plants12071512 - 30 Mar 2023

Cited by 42 | Viewed by 14629

Abstract

The cactus, Opuntia ficus-indica (L.) Mill. (OFI) belongs to the Cactaceae family, which contains about 130 genera and nearly 1600 species. This review aims to evaluate this plant from several perspectives, namely, botanic, physicochemical, nutritional, and medicinal properties, as well as agro-industrial use. [...] Read more.

The cactus, Opuntia ficus-indica (L.) Mill. (OFI) belongs to the Cactaceae family, which contains about 130 genera and nearly 1600 species. This review aims to evaluate this plant from several perspectives, namely, botanic, physicochemical, nutritional, and medicinal properties, as well as agro-industrial use. The botanical aspects and morphological characteristics of OFI enable genetic variability, ecological adaptation, and broad geographic distribution. Due to its physicochemical and nutritional composition, it has several medicinal properties appropriate (or suitable) for several industries, such as pharmaceutical, food, and cosmetics. Its fruit, the prickly pear (PP), has potential agro-industrial expansion through the application of different conservation and transformation methods, making it possible to obtain a variety of products. The PP is a source of several nutrients and is an effective system to produce varied foods, which have several advantages from a nutritional, sensory, economic, and shelf-life point of view. Full article

(This article belongs to the Special Issue Plant Nutrition Volume II)

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23 pages, 4219 KiB

Open AccessEditor’s ChoiceArticle

Physiological and Morphological Responses of Blackberry Seedlings to Different Nitrogen Forms

by Yongkang Duan, Haiyan Yang, Hao Yang, Zhiwen Wei, Jilu Che, Wenlong Wu, Lianfei Lyu and Weilin Li

Plants 2023, 12(7), 1480; https://doi.org/10.3390/plants12071480 - 28 Mar 2023

Cited by 22 | Viewed by 4055

Abstract

Blackberries are an emerging third-generation fruit that are popular in Europe, and specific nitrogen (N) supply is an important factor affecting their growth and development. To study the optimal N fertilizer for blackberry seedlings, no N (CK), nitrate (NO₃⁻)–N, ammonium [...] Read more.

Blackberries are an emerging third-generation fruit that are popular in Europe, and specific nitrogen (N) supply is an important factor affecting their growth and development. To study the optimal N fertilizer for blackberry seedlings, no N (CK), nitrate (NO₃⁻)–N, ammonium (NH₄⁺)–N and urea were applied to one-year-old ‘Ningzhi 4’ blackberry plants at a key growth period (from May to August) to explore the effects of different N forms on the physiological characteristics. Correlation and principal component analysis were used to determine the relationships between various indexes. Ammonium (NH₄⁺) or urea-fed plants had a better growth state, showed a greater plant height, biomass, SPAD values and enhanced antioxidant enzyme activities and photosynthesis. In addition, NH₄⁺ was beneficial to the accumulation of sugars and amino acids in leaves and roots, and promoted the transport of auxin and cytokinin to leaves. NO₃⁻ significantly inhibited root growth and increased the contents of active oxygen, malondialdehyde and antioxidants in roots. Correlation and principal component analysis showed that growth and dry matter accumulation were closely related to the antioxidant system, photosynthetic characteristics, amino acids and hormone content. Our study provides a new idea for N regulation mechanism of blackberry and proposes a scientific fertilization strategy. Full article

(This article belongs to the Special Issue Role of Nitrogen in Plant Growth and Development)

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13 pages, 2038 KiB

Open AccessEditor’s ChoiceArticle

Conventional vs. Microwave-Assisted Hydrodistillation: Influence on the Chemistry of Sea Fennel Essential Oil and Its By-Products

by Olivera Politeo, Marijana Popović, Maja Veršić Bratinčević, Petra Koceić, Tonka Ninčević Runjić and Ivana Generalić Mekinić

Plants 2023, 12(7), 1466; https://doi.org/10.3390/plants12071466 - 27 Mar 2023

Cited by 21 | Viewed by 2383

Abstract

The main objectives of this study were to investigate the effects of the applied essential oil (EO) isolation method, conventional hydro-distillation (HD), and microwave-assisted hydro-distillation (MHD) on the chemical profile of sea fennel (Crithmum maritimum L.) essential oil and to investigate the [...] Read more.

The main objectives of this study were to investigate the effects of the applied essential oil (EO) isolation method, conventional hydro-distillation (HD), and microwave-assisted hydro-distillation (MHD) on the chemical profile of sea fennel (Crithmum maritimum L.) essential oil and to investigate the main constituents present in the liquid by-products of EOs isolation (hydrolate and residual wastewater). Headspace-solid phase microextraction (HS-SPME) was used to isolate hydrolate components, while gas chromatography coupled with mass spectrometry (GC-MS) was used to detect and analyse the chemical constituents of the essential oils and hydrolates. The phenolic composition of the wastewater extracts was analysed by high performance liquid chromatography (HPLC). The EO obtained by MHD had a higher yield of limonene and sabinene. The chemical composition of the hydrolates differed from the EO compositions. The content of terpinen-4-ol in the MHD hydrolate was higher, while several compounds were detected in relatively high proportions only in the HD hydrolate. MHD also resulted in a higher phenolic content of the wastewater, where an increase in the concentration of chlorogenic acid was also observed. It can be concluded that the isolation method had a great influence on the profile of sea fennel EOs, especially on their corresponding hydrolates and residual wastewater extracts. Due to their valuable chemical composition, these by-products can be a cost-effective source of bioactive compounds that have great potential for use in various industries. Full article

(This article belongs to the Special Issue Biosynthesis, Function, and Application of Plant Volatiles II)

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23 pages, 51792 KiB

Open AccessEditor’s ChoiceArticle

Green Synthesis of Iron Oxide (Hematite) Nanoparticles and Their Influence on Sorghum bicolor Growth under Drought Stress

by Nzumbululo Ndou, Tessia Rakgotho, Mulisa Nkuna, Ibrahima Zan Doumbia, Takalani Mulaudzi and Rachel Fanelwa Ajayi

Plants 2023, 12(7), 1425; https://doi.org/10.3390/plants12071425 - 23 Mar 2023

Cited by 30 | Viewed by 5832

Abstract

Drought is a major abiotic stress that confronts plant growth and productivity, thus compromising food security. Plants use physiological and biochemical mechanisms to cope with drought stress, but at the expense of growth. Green-synthesized nanoparticles (NPs) have gained great attention in agriculture due [...] Read more.

Drought is a major abiotic stress that confronts plant growth and productivity, thus compromising food security. Plants use physiological and biochemical mechanisms to cope with drought stress, but at the expense of growth. Green-synthesized nanoparticles (NPs) have gained great attention in agriculture due to their environmental friendliness and affordability while serving as potential biofertilizers. This study investigates the role of hematite (αFe₂O₃) NPs, synthesized from Aspalathus linearis (rooibos), to improve Sorghum bicolor growth under drought stress. About 18 nm, spherical, and highly agglomerated hematite (αFe₂O₃) NPs were obtained. Sorghum seeds were primed with 5, 10, and 15 mg/L αFe₂O₃ NPs, and, after seven days of germination, the seedlings were transferred into potting soil, cultivated for fourteen days, and were subsequently water deprived (WD) for a further seven days. A reduction in plant height (78%), fresh (FW; 35%) and dry (DW; 36%) weights, and chlorophyll (chl) content ((total chl (81%), chla (135%), and chlb (1827%)) was observed in WD plants, and this correlated with low nutrients (Mg, Si, P, and K) and alteration in the anatomic structure (epidermis and vascular bundle tissues). Oxidative damage was observed as deep blue (O₂^●−) and brown (H₂O₂) spots on the leaves of WD plants, in addition to a 25% and 40% increase in oxidative stress markers (H₂O₂ and MDA) and osmolytes (proline and total soluble sugars), respectively. Seed priming with 10 mg/L αFe₂O₃ NPs improved plant height (70%), FW (56%), DW (34%), total Chl (104%), chla (160%) and chlb (1936%), anatomic structure, and nutrient distribution. Priming with 10 mg/L αFe₂O₃ NPs also protected sorghum plants from drought-induced oxidative damage by reducing ROS formation and osmolytes accumulation and prevented biomolecule degradation. The study concludes that green synthesized hematite NPs positively influenced sorghum growth and prevented oxidative damage of biomolecules by improving nutrient uptake and osmoregulation under drought stress. Full article

(This article belongs to the Special Issue Effects of Nanoparticles on Plant Growth and Development under Biotic and Abiotic Stress)

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15 pages, 4369 KiB

Open AccessEditor’s ChoiceArticle

Chlorophyll Fluorescence Imaging for Early Detection of Drought and Heat Stress in Strawberry Plants

by Muhammad Akbar Andi Arief, Hangi Kim, Hary Kurniawan, Andri Prima Nugroho, Taehyun Kim and Byoung-Kwan Cho

Plants 2023, 12(6), 1387; https://doi.org/10.3390/plants12061387 - 21 Mar 2023

Cited by 51 | Viewed by 9391

Abstract

The efficiency of photosynthesis in strawberry plants is measured to maintain the quality and quantity of strawberries produced. The latest method used to measure the photosynthetic status of plants is chlorophyll fluorescence imaging (CFI), which has the advantage of obtaining plant spatiotemporal data [...] Read more.

The efficiency of photosynthesis in strawberry plants is measured to maintain the quality and quantity of strawberries produced. The latest method used to measure the photosynthetic status of plants is chlorophyll fluorescence imaging (CFI), which has the advantage of obtaining plant spatiotemporal data non-destructively. This study developed a CFI system to measure the maximum quantum efficiency of photochemistry (Fv/Fm). The main components of this system include a chamber for plants to adapt to dark environments, blue LED light sources to excite the chlorophyll in plants, and a monochrome camera with a lens filter attached to capture the emission spectra. In this study, 120 pots of strawberry plants were cultivated for 15 days and divided into four treatment groups: control, drought stress, heat stress, and a combination of drought and heat stress, resulting in Fv/Fm values of 0.802 ± 0.0036, 0.780 ± 0.0026, 0.768 ± 0.0023, and 0.749 ± 0.0099, respectively. A strong correlation was found between the developed system and a chlorophyll meter (r = 0.75). These results prove that the developed CFI system can accurately capture the spatial and temporal dynamics resulting from the response of strawberry plants to abiotic stresses. Full article

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14 pages, 2680 KiB

Open AccessEditor’s ChoiceArticle

Development and the Effect of Weather and Mineral Fertilization on Grain Yield and Stability of Winter Wheat following Alfalfa—Analysis of Long-Term Field Trial

by Lukáš Hlisnikovský, Ladislav Menšík and Eva Kunzová

Plants 2023, 12(6), 1392; https://doi.org/10.3390/plants12061392 - 21 Mar 2023

Cited by 12 | Viewed by 2193

Abstract

Within the framework of a long-term experiment, established in 1955, we evaluated the development and effects of weather and mineral fertilization (Control, NPK1, NPK2, NPK3, NPK4) on the yield and stability of winter wheat following alfalfa. In total, 19 seasons were analysed. The [...] Read more.

Within the framework of a long-term experiment, established in 1955, we evaluated the development and effects of weather and mineral fertilization (Control, NPK1, NPK2, NPK3, NPK4) on the yield and stability of winter wheat following alfalfa. In total, 19 seasons were analysed. The weather changed considerably at the experimental site. Significant increases in minimal, mean, and maximal temperatures were dated to the period 1987–1988, while precipitation remained the same to this day (insignificantly increasing trend by 0.5 mm per annum). Rising temperatures in November, May, and July positively affected wheat grain yield, especially in treatments with higher N doses. No relationship between yield and precipitation was recorded. Highest inter-annual yield variability was recorded in Control and NPK4 treatments. Although minerally fertilized treatments provided slightly higher yields, the difference between Control and NPK treatments was insignificant. According to the linear-plateau response model, the recommended dose of 44 kg ha⁻¹ N corresponds with yield of 7.4 t ha⁻¹, while Control provides an average yield of 6.8 t ha⁻¹. The application of higher doses did not lead to significant grain yield increase. Alfalfa as a preceding crop reduces the need of N fertilization and contributes to sustainable conventional agriculture, however, its share in crop rotations is decreasing both in the Czech Republic and in Europe. Full article

(This article belongs to the Section Crop Physiology and Crop Production)

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24 pages, 5823 KiB

Open AccessEditor’s ChoiceArticle

Chemical Composition and Biological Activities of Essential Oils from Origanum vulgare Genotypes Belonging to the Carvacrol and Thymol Chemotypes

by Paola Zinno, Barbara Guantario, Gabriele Lombardi, Giulia Ranaldi, Alberto Finamore, Sofia Allegra, Michele Massimo Mammano, Giancarlo Fascella, Antonio Raffo and Marianna Roselli

Plants 2023, 12(6), 1344; https://doi.org/10.3390/plants12061344 - 16 Mar 2023

Cited by 31 | Viewed by 5155

Abstract

The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely [...] Read more.

The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely cultivated in Sicily and not previously studied for their biological properties, were characterized. Plants of the two genotypes, belonging to the carvacrol (CAR) and thymol (THY) chemotypes and grown in different cultivation environments, were considered for this study. The chemical profiles, including the determination of enantiomeric distribution, of the EOs, obtained by hydrodistillation from dried leaves and flowers, were investigated by GC–MS. Biological activity was evaluated as antimicrobial properties against different pathogen indicator strains, while intestinal barrier integrity, reduction in pathogen adhesion and anti-inflammatory actions were assayed in the intestinal Caco-2 cell line. The chemical profile of the CAR genotype was less complex and characterized by higher levels of the most active compound, i.e., carvacrol, when compared to the THY genotype. The enantiomeric distribution of chiral constituents did not vary across genotypes, while being markedly different from that observed in Origanum vulgare genotypes from other geographical origins. In general, all EOs showed high antimicrobial activity, both in vitro and in a food matrix challenge test. Representative EOs from the two genotypes resulted not altering epithelial monolayer sealing only for concentrations lower than 0.02%, were able to reduce the adhesion of selected pathogens, but did not exert relevant anti-inflammatory effects. These results suggest their potential use as control agents against a wide spectrum of foodborne pathogens. Full article

(This article belongs to the Special Issue Plant Essential Oil with Biological Activity II)

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29 pages, 574 KiB

Open AccessEditor’s ChoiceReview

Cowpea Constraints and Breeding in Europe

by Efstathia Lazaridi and Penelope J. Bebeli

Plants 2023, 12(6), 1339; https://doi.org/10.3390/plants12061339 - 16 Mar 2023

Cited by 9 | Viewed by 5189

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is a legume with a constant rate of cultivation in Southern European countries. Consumer demand for cowpea worldwide is rising due to its nutritional content, while Europe is constantly attempting to reduce the deficit in the production [...] Read more.

Cowpea (Vigna unguiculata (L.) Walp.) is a legume with a constant rate of cultivation in Southern European countries. Consumer demand for cowpea worldwide is rising due to its nutritional content, while Europe is constantly attempting to reduce the deficit in the production of pulses and invest in new, healthy food market products. Although the climatic conditions that prevail in Europe are not so harsh in terms of heat and drought as in the tropical climates where cowpea is mainly cultivated, cowpea confronts with a plethora of abiotic and biotic stresses and yield-limiting factors in Southern European countries. In this paper, we summarize the main constraints for cowpea cultivation in Europe and the breeding methods that have been or can be used. A special mention is made of the availability plant genetic resources (PGRs) and their potential for breeding purposes, aiming to promote more sustainable cropping systems as climatic shifts become more frequent and fiercer, and environmental degradation expands worldwide. Full article

(This article belongs to the Special Issue Breeding and Cultivation Management of Legumes)

19 pages, 6413 KiB

Open AccessEditor’s ChoiceArticle

Metabolic Profiling of Primary and Secondary Metabolites in Kohlrabi (Brassica oleracea var. gongylodes) Sprouts Exposed to Different Light-Emitting Diodes

by Ramaraj Sathasivam, Sang Un Park, Jae Kwang Kim, Young Jin Park, Min Cheol Kim, Bao Van Nguyen and Sook Young Lee

Plants 2023, 12(6), 1296; https://doi.org/10.3390/plants12061296 - 13 Mar 2023

Cited by 22 | Viewed by 3019

Abstract

Light-emitting diode (LED) technology is one of the most important light sources in the plant industry for enhancing growth and specific metabolites in plants. In this study, we analyzed the growth, primary and secondary metabolites of 10 days old kohlrabi (Brassica oleracea [...] Read more.

Light-emitting diode (LED) technology is one of the most important light sources in the plant industry for enhancing growth and specific metabolites in plants. In this study, we analyzed the growth, primary and secondary metabolites of 10 days old kohlrabi (Brassica oleracea var. gongylodes) sprouts exposed to different LED light conditions. The results showed that the highest fresh weight was achieved under red LED light, whereas the highest shoot and root lengths were recorded below the blue LED light. Furthermore, high-performance liquid chromatography (HPLC) analysis revealed the presence of 13 phenylpropanoid compounds, 8 glucosinolates (GSLs), and 5 different carotenoids. The phenylpropanoid and GSL contents were highest under blue LED light. In contrast, the carotenoid content was found to be maximum beneath white LED light. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) of the 71 identified metabolites using HPLC and gas chromatography–time-of-flight mass spectrometry (GC-TOF-MS) showed a clear separation, indicating that different LEDs exhibited variation in the accumulation of primary and secondary metabolites. A heat map and hierarchical clustering analysis revealed that blue LED light accumulated the highest amount of primary and secondary metabolites. Overall, our results demonstrate that exposure of kohlrabi sprouts to blue LED light is the most suitable condition for the highest growth and is effective in increasing the phenylpropanoid and GSL content, whereas white light might be used to enhance carotenoid compounds in kohlrabi sprouts. Full article

(This article belongs to the Special Issue The Effects of LED Light Spectra and Intensities on Plant Growth 2.0)

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20 pages, 1907 KiB

Open AccessEditor’s ChoiceArticle

Water and Nutrient Recovery for Cucumber Hydroponic Cultivation in Simultaneous Biological Treatment of Urine and Grey Water

by Anna Wdowikowska, Małgorzata Reda, Katarzyna Kabała, Piotr Chohura, Anna Jurga, Kamil Janiak and Małgorzata Janicka

Plants 2023, 12(6), 1286; https://doi.org/10.3390/plants12061286 - 12 Mar 2023

Cited by 13 | Viewed by 4257

Abstract

Water and nutrient deficiencies in soil are becoming a serious threat to crop production. Therefore, usable water and nutrient recovery from wastewater, such as urine and grey water, should be considered. In this work, we showed the possibility of using grey water and [...] Read more.

Water and nutrient deficiencies in soil are becoming a serious threat to crop production. Therefore, usable water and nutrient recovery from wastewater, such as urine and grey water, should be considered. In this work, we showed the possibility of using grey water and urine after processing in an aerobic reactor with activated sludge in which the nitrification process takes place. The resulting liquid (nitrified urine and grey water, NUG) contains three potential factors that can adversely affect plant growth in a hydroponic system: anionic surfactants, nutrient deficits, and salinity. After dilution and supplementation with small amounts of macro- and micro-elements, NUG was suitable for cucumber cultivation. Plant growth on this modified medium (enriched nitrified urine and grey water, NUGE) was similar to that of plants cultivated on Hoagland solution (HS) and reference commercial fertilizer (RCF). The modified medium (NUGE) contained a significant amount of sodium (Na) ions. Therefore, typical effects of salt stress were observed in cucumber plants, including reduced chlorophyll levels, slightly weaker photosynthesis parameters, increased H₂O₂ levels, lipid peroxidation, ascorbate peroxidase (APX) activity, and proline content in the leaves. In addition, reduced protein levels were observed in plants treated with recycled medium. At the same time, lower nitrate content in tissues was found, which may have resulted from their intensive use by nitrate reductase (NR), the activity of which significantly increased. Although cucumber is a glycophyte, it grew very well in this recycled medium. Interestingly, salt stress and possibly anionic surfactants promoted flower formation, which in turn could positively affect plant yield. Full article

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

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26 pages, 2310 KiB

Open AccessEditor’s ChoiceReview

Medicinal Uses of the Fabaceae Family in Zimbabwe: A Review

by Alfred Maroyi

Plants 2023, 12(6), 1255; https://doi.org/10.3390/plants12061255 - 10 Mar 2023

Cited by 40 | Viewed by 9270

Abstract

The current study is aimed at providing a systematic review of the ethnomedicinal, phytochemical and pharmacological properties of Fabaceae species used as sources of traditional medicinies in Zimbabwe. Fabaceae is one of the well-known plant families of ethnopharmacological importance. Of the approximately 665 [...] Read more.

The current study is aimed at providing a systematic review of the ethnomedicinal, phytochemical and pharmacological properties of Fabaceae species used as sources of traditional medicinies in Zimbabwe. Fabaceae is one of the well-known plant families of ethnopharmacological importance. Of the approximately 665 species of the Fabaceae family occurring in Zimbabwe, about 101 are used for medicinal purposes. Many communities in the country, mainly in peri-urban, rural and marginalized areas with limited access to healthcare facilities, rely on traditional medicines as their primary healthcare. The study reviewed research studies undertaken on Zimbabwe’s Fabaceae species during 1959 to 2022. Information was gathered from literature sourced from Google Scholar, Science Direct, Scopus, PubMed, books, dissertations, theses and scientific reports. This study showed that 101 species are traditionally used to manage human and animal diseases in Zimbabwe. The genera with the highest number of medicinal uses are Indigofera, Senna, Albizia, Rhynchosia and Vachellia. Species of these genera are used as traditional medicines against 134 medical conditions, mainly gastrointestinal conditions, female reproductive conditions, respiratory conditions and sexually transmitted infections. Shrubs (39.0%), trees (37.0%) and herbs (18.0%) are the primary sources of traditional medicines, while roots (80.2%), leaves (36.6%), bark (27.7%) and fruits (8.9%) are the most widely used plant parts. Many of Zimbabwe’s Fabaceae species used as sources of traditional medicines have been assessed for their phytochemical and pharmacological properties, corroborating their medicinal uses. However, there is a need to unravel the therapeutic potential of the family through further ethnopharmacological research focusing on toxicological studies, in vitro and in vivo models, biochemical assays and pharmacokinetic studies. Full article

(This article belongs to the Special Issue Phytochemistry and Pharmacological Properties of Medicinal Plants)

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12 pages, 1493 KiB

Open AccessEditor’s ChoiceArticle

Accumulation of Toxic Arsenic by Cherry Radish Tuber (Raphanus sativus var. sativus Pers.) and Its Physiological, Metabolic and Anatomical Stress Responses

by Daniela Pavlíková, Milan Pavlík, Veronika Zemanová, Milan Novák, Petr Doležal, Petre I. Dobrev, Václav Motyka and Kamil Kraus

Plants 2023, 12(6), 1257; https://doi.org/10.3390/plants12061257 - 10 Mar 2023

Cited by 9 | Viewed by 2189

Abstract

In a pot experiment, cherry radish (Raphanus sativus var. sativus Pers. ‘Viola’) was cultivated under two levels of As soil contamination—20 and 100 mg/kg. The increasing As content in tubers with increasing soil contamination led to changes in free amino acids (AAs) [...] Read more.

In a pot experiment, cherry radish (Raphanus sativus var. sativus Pers. ‘Viola’) was cultivated under two levels of As soil contamination—20 and 100 mg/kg. The increasing As content in tubers with increasing soil contamination led to changes in free amino acids (AAs) and phytohormone metabolism and antioxidative metabolites. Changes were mainly observed under conditions of high As contamination (As100). The content of indole-3-acetic acid in tubers varied under different levels of As stress, but As100 contamination led to an increase in its bacterial precursor indole-3-acetamide. A decrease in cis-zeatin-9-riboside-5′-monophosphate content and an increase in jasmonic acid content were found in this treatment. The free AA content in tubers was also reduced. The main free AAs were determined to be transport AAs (glutamate—Glu, aspartate, glutamine—Gln, asparagine) with the main portion being Gln. The Glu/Gln ratio—a significant indicator of primary N assimilation in plants—decreased under the As100 treatment condition. A decrease in antioxidative metabolite content—namely that of ascorbic acid and anthocyanins—was observed in this experiment. A decline in anthocyanin content is related to a decrease in aromatic AA content which is crucial for secondary metabolite production. The changes in tubers caused by As contamination were reflected in anatomical changes in the radish tubers and roots. Full article

(This article belongs to the Special Issue Plant Physiological, Biochemical, and Molecular Responses to Abiotic Stresses 2.0)

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43 pages, 3229 KiB

Open AccessEditor’s ChoiceReview

A Comprehensive Review on Cannabis sativa Ethnobotany, Phytochemistry, Molecular Docking and Biological Activities

by Sohaib Hourfane, Hicham Mechqoq, Abdellah Yassine Bekkali, João Miguel Rocha and Noureddine El Aouad

Plants 2023, 12(6), 1245; https://doi.org/10.3390/plants12061245 - 9 Mar 2023

Cited by 57 | Viewed by 20080

Abstract

For more than a century, Cannabis was considered a narcotic and has been banned by lawmakers all over the world. In recent years, interest in this plant has increased due to its therapeutic potential, in addition to a very interesting chemical composition, characterized [...] Read more.

For more than a century, Cannabis was considered a narcotic and has been banned by lawmakers all over the world. In recent years, interest in this plant has increased due to its therapeutic potential, in addition to a very interesting chemical composition, characterized by the presence of an atypical family of molecules known as phytocannabinoids. With this emerging interest, it is very important to take stock of what research has been conducted so far on the chemistry and biology of Cannabis sativa. The aim of this review is to describe the traditional uses, chemical composition and biological activities of different parts of this plant, as well as the molecular docking studies. Information was collected from electronic databases, namely SciFinder, ScienceDirect, PubMed and Web of Science. Cannabis is mainly popular for its recreational use, but it is also traditionally used as remedy for the treatment of several diseases, including diabetes, digestive, circulatory, genital, nervous, urinary, skin and respiratory diseases. These biological proprieties are mainly due to the presence of bioactive metabolites represented by more than 550 different molecules. Molecular docking simulations proved the presence of affinities between Cannabis compounds and several enzymes responsible for anti-inflammatory, antidiabetic, antiepileptic and anticancer activities. Several biological activities have been evaluated on the metabolites of Cannabis sativa, and these works have shown the presence of antioxidant, antibacterial, anticoagulant, antifungal, anti-aflatoxigenic, insecticidal, anti-inflammatory, anticancer, neuroprotective and dermocosmetic activities. This paper presents the up-to-date reported investigations and opens many reflections and further research perspectives. Full article

(This article belongs to the Special Issue Biological and Chemical Activity of Metabolites of Medicinal Plants)

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21 pages, 624 KiB

Open AccessEditor’s ChoiceReview

Agronomical Practices and Management for Commercial Cultivation of Portulaca oleracea as a Crop: A Review

by Angel Carrascosa, Jose Antonio Pascual, Margarita Ros, Spyridon A. Petropoulos and Maria del Mar Alguacil

Plants 2023, 12(6), 1246; https://doi.org/10.3390/plants12061246 - 9 Mar 2023

Cited by 23 | Viewed by 6575

Abstract

Soil is an essential resource, and its degradation is challenging modern agriculture, while its impact is expected to increase in the near future. One of the strategies to address this issue is to incorporate new alternative crops able to tolerate arduous conditions, as [...] Read more.

Soil is an essential resource, and its degradation is challenging modern agriculture, while its impact is expected to increase in the near future. One of the strategies to address this issue is to incorporate new alternative crops able to tolerate arduous conditions, as well as for the use of sustainable agricultural practices in order to recover and/or improve soil health. Additionally, the increasing market for new functional/healthy natural foods promotes the search for potential alternative crop species with promising bioactive compounds content. For this purpose, wild edible plants are a key option because they have already been consumed for hundreds of years in traditional gastronomy and there is well-established evidence of their health-promoting effects. Moreover, since they are not a cultivated species, they are able to grow under natural conditions without human intervention. Among them, common purslane is an interesting wild edible species and a good candidate for integration in commercial farming systems. With worldwide spread, it is able to tolerate drought, salinity and heat stress and is already used in traditional dishes, while it is highly appreciated for its high nutritional value due to its bioactive compound content, especially omega-3 fatty acids. In this review, we aim to present the breeding and cultivation practices of purslane, as well as the effects of abiotic stressors on yield and chemical composition of the edible parts. Finally, we present information that helps to optimize purslane cultivation and facilitate its management in degraded soils for their exploitation in the existing farming systems. 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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34 pages, 4238 KiB

Open AccessEditor’s ChoiceReview

Water Content of Plant Tissues: So Simple That Almost Forgotten?

by Gederts Ievinsh

Plants 2023, 12(6), 1238; https://doi.org/10.3390/plants12061238 - 8 Mar 2023

Cited by 49 | Viewed by 19603

Abstract

The aim of the present review was to reconsider basic information about various functional aspects related to plant water content and provide evidence that the usefulness of measuring absolute water content in plant sciences is undervalued. First, general questions about water status in [...] Read more.

The aim of the present review was to reconsider basic information about various functional aspects related to plant water content and provide evidence that the usefulness of measuring absolute water content in plant sciences is undervalued. First, general questions about water status in plants as well as methods for determining water content and their associated problems were discussed. After a brief overview of the structural organization of water in plant tissues, attention was paid to the water content of different parts of plants. Looking at the influence of environmental factors on plant water status, the differences caused by air humidity, mineral supply, biotic effects, salinity, and specific life forms (clonal and succulent plants) were analyzed. Finally, it was concluded that the expression of absolute water content on a dry biomass basis makes easily noticeable functional sense, but the physiological meaning and ecological significance of the drastic differences in plant water content need to be further elucidated. Full article

(This article belongs to the Collection Feature Papers in Plant Physiology and Metabolism)

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18 pages, 3307 KiB

Open AccessEditor’s ChoiceArticle

A Plant Biostimulant from Ascophyllum nodosum Potentiates Plant Growth Promotion and Stress Protection Activity of Pseudomonas protegens CHA0

by Jai Singh Patel, Vinodkumar Selvaraj, Prashant More, Ramin Bahmani, Tudor Borza and Balakrishnan Prithiviraj

Plants 2023, 12(6), 1208; https://doi.org/10.3390/plants12061208 - 7 Mar 2023

Cited by 10 | Viewed by 3785

Abstract

Abiotic stresses, including salinity stress, affect numerous crops, causing yield reduction, and, as a result, important economic losses. Extracts from the brown alga Ascophyllum nodosum (ANE), and compounds secreted by the Pseudomonas protegens strain, CHA0, can mitigate these effects by inducing tolerance against [...] Read more.

Abiotic stresses, including salinity stress, affect numerous crops, causing yield reduction, and, as a result, important economic losses. Extracts from the brown alga Ascophyllum nodosum (ANE), and compounds secreted by the Pseudomonas protegens strain, CHA0, can mitigate these effects by inducing tolerance against salt stress. However, the influence of ANE on P. protegens CHA0 secretion, and the combined effects of these two biostimulants on plant growth, are not known. Fucoidan, alginate, and mannitol are abundant components of brown algae and of ANE. Reported here are the effects of a commercial formulation of ANE, fucoidan, alginate, and mannitol, on pea (Pisum sativum), and on the plant growth-promoting activity of P. protegens CHA0. In most situations, ANE and fucoidan increased indole-3-acetic acid (IAA) and siderophore production, phosphate solubilization, and hydrogen cyanide (HCN) production by P. protegens CHA0. Colonization of pea roots by P. protegens CHA0 was found to be increased mostly by ANE and fucoidan in normal conditions and under salt stress. Applications of P. protegens CHA0 combined with ANE, or with fucoidan, alginate, and mannitol, generally augmented root and shoot growth in normal and salinity stress conditions. Real-time quantitative PCR analyses of P. protegens revealed that, in many instances, ANE and fucoidan enhanced the expression of several genes involved in chemotaxis (cheW and WspR), pyoverdine production (pvdS), and HCN production (hcnA), but gene expression patterns overlapped only occasionally those of growth-promoting parameters. Overall, the increased colonization and the enhanced activities of P. protegens CHA0 in the presence of ANE and its components mitigated salinity stress in pea. Among treatments, ANE and fucoidan were found responsible for most of the increased activities of P. protegens CHA0 and the improved plant growth. Full article

(This article belongs to the Special Issue Salinity Stress Tolerance in Plants)

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25 pages, 1647 KiB

Open AccessEditor’s ChoiceArticle

Phytoremediation Potential of Native Plant Species in Mine Soils Polluted by Metal(loid)s and Rare Earth Elements

by Mitra Azizi, Angel Faz, Raul Zornoza, Silvia Martinez-Martinez and Jose A. Acosta

Plants 2023, 12(6), 1219; https://doi.org/10.3390/plants12061219 - 7 Mar 2023

Cited by 31 | Viewed by 6802

Abstract

Mining activity has an adverse impact on the surrounding ecosystem, especially via the release of potentially toxic elements (PTEs); therefore, there is an urgent need to develop efficient technologies to remediate these ecosystems, especially soils. Phytoremediation can be potentially used to remediate contaminated [...] Read more.

Mining activity has an adverse impact on the surrounding ecosystem, especially via the release of potentially toxic elements (PTEs); therefore, there is an urgent need to develop efficient technologies to remediate these ecosystems, especially soils. Phytoremediation can be potentially used to remediate contaminated areas by potentially toxic elements. However, in soils affected by polymetallic contamination, including metals, metalloids, and rare earth elements (REEs), it is necessary to evaluate the behavior of these toxic elements in the soil-plant system, which will allow the selection of the most appropriate native plants with phytoremediation potential to be used in phytoremediation programs. This study was conducted to evaluate the level of contamination of 29 metal(loid)s and REEs in two natural soils and four native plant species (Salsola oppositifolia, Stipa tenacissima, Piptatherum miliaceum, and Artemisia herba-alba) growing in the vicinity of a Pb-(Ag)-Zn mine and asses their phytoextraction and phytostabilization potential. The results indicated that very high soil contamination was found for Zn, Fe, Al, Pb, Cd, As, Se, and Th, considerable to moderate contamination for Cu, Sb, Cs, Ge Ni, Cr, and Co, and low contamination for Rb, V, Sr, Zr, Sn, Y, Bi and U in the study area, dependent of sampling place. Available fraction of PTEs and REEs in comparison to total concentration showed a wide range from 0% for Sn to more than 10% for Pb, Cd, and Mn. Soil properties such as pH, electrical conductivity, and clay content affect the total, available, and water-soluble concentrations of different PTEs and REEs. The results obtained from plant analysis showed that the concentration of PTEs in shoots could be at a toxicity level (Zn, Pb, and Cr), lower than toxic but more than sufficient or natural concentration accepted in plants (Cd, Ni, and Cu) or at an acceptable level (e.g., V, As, Co, and Mn). Accumulation of PTEs and REEs in plants and the translocation from root to shoot varied between plant species and sampling soils. A. herba-alba is the least efficient plant in the phytoremediation process; P. miliaceum was a good candidate for phytostabilization of Pb, Cd, Cu, V, and As, and S. oppositifolia for phytoextraction of Zn, Cd, Mn, and Mo. All plant species except A. herba-alba could be potential candidates for phytostabilization of REEs, while none of the plant species has the potential to be used in the phytoextraction of REEs. Full article

(This article belongs to the Special Issue Phytomonitoring and Phytoremediation of Environmental Pollutants)

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18 pages, 698 KiB

Open AccessEditor’s ChoiceReview

Turning Garlic into a Modern Crop: State of the Art and Perspectives

by Ricardo Parreño, Eva Rodríguez-Alcocer, César Martínez-Guardiola, Lucía Carrasco, Purificación Castillo, Vicent Arbona, Sara Jover-Gil and Héctor Candela

Plants 2023, 12(6), 1212; https://doi.org/10.3390/plants12061212 - 7 Mar 2023

Cited by 18 | Viewed by 10773

Abstract

Garlic is cultivated worldwide for the value of its bulbs, but its cultivation is challenged by the infertility of commercial cultivars and the accumulation of pathogens over time, which occurs as a consequence of vegetative (clonal) propagation. In this review, we summarize the [...] Read more.

Garlic is cultivated worldwide for the value of its bulbs, but its cultivation is challenged by the infertility of commercial cultivars and the accumulation of pathogens over time, which occurs as a consequence of vegetative (clonal) propagation. In this review, we summarize the state of the art of garlic genetics and genomics, highlighting recent developments that will lead to its development as a modern crop, including the restoration of sexual reproduction in some garlic strains. The set of tools available to the breeder currently includes a chromosome-scale assembly of the garlic genome and multiple transcriptome assemblies that are furthering our understanding of the molecular processes underlying important traits like the infertility, the induction of flowering and bulbing, the organoleptic properties and resistance to various pathogens. Full article

(This article belongs to the Special Issue Genetic Improvement of Horticultural Plants for Yield, Quality, and Resistance to Diseases)

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20 pages, 1222 KiB

Open AccessEditor’s ChoiceArticle

Effects of Extraction Methods on Phenolic Content, Antioxidant and Antiplatelet Activities of Tomato Pomace Extracts

by Andrea Plaza, Lyanne Rodríguez, Anibal A. Concha-Meyer, René Cabezas, Elsie Zurob, Gastón Merlet, Iván Palomo and Eduardo Fuentes

Plants 2023, 12(5), 1188; https://doi.org/10.3390/plants12051188 - 6 Mar 2023

Cited by 17 | Viewed by 4215

Abstract

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, °Brix, and antiplatelet activity of the extracts were obtained, a multivariate [...] Read more.

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, °Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 °C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid–liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace. Full article

(This article belongs to the Special Issue Pharmacology and Toxicology of Plants and Their Constituents)

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14 pages, 8040 KiB

Open AccessEditor’s ChoiceArticle

A High Performance Wheat Disease Detection Based on Position Information

by Siyu Cheng, Haolan Cheng, Ruining Yang, Junyu Zhou, Zongrui Li, Binqin Shi, Marshall Lee and Qin Ma

Plants 2023, 12(5), 1191; https://doi.org/10.3390/plants12051191 - 6 Mar 2023

Cited by 24 | Viewed by 4070

Abstract

Protecting wheat yield is a top priority in agricultural production, and one of the important measures to preserve yield is the control of wheat diseases. With the maturity of computer vision technology, more possibilities have been provided to achieve plant disease detection. In [...] Read more.

Protecting wheat yield is a top priority in agricultural production, and one of the important measures to preserve yield is the control of wheat diseases. With the maturity of computer vision technology, more possibilities have been provided to achieve plant disease detection. In this study, we propose the position attention block, which can effectively extract the position information from the feature map and construct the attention map to improve the feature extraction ability of the model for the region of interest. For training, we use transfer learning to improve the training speed of the model. In the experiment, ResNet built on positional attention blocks achieves 96.4% accuracy, which is much higher compared to other comparable models. Afterward, we optimized the undesirable detection class and validated its generalization performance on an open-source dataset. Full article

(This article belongs to the Section Plant Modeling)

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27 pages, 5762 KiB

Open AccessEditor’s ChoiceReview

Chronic Ionizing Radiation of Plants: An Evolutionary Factor from Direct Damage to Non-Target Effects

by Gustavo Turqueto Duarte, Polina Yu. Volkova, Fabricio Fiengo Perez and Nele Horemans

Plants 2023, 12(5), 1178; https://doi.org/10.3390/plants12051178 - 4 Mar 2023

Cited by 32 | Viewed by 9553

Abstract

In present times, the levels of ionizing radiation (IR) on the surface of Earth are relatively low, posing no high challenges for the survival of contemporary life forms. IR derives from natural sources and naturally occurring radioactive materials (NORM), the nuclear industry, medical [...] Read more.

In present times, the levels of ionizing radiation (IR) on the surface of Earth are relatively low, posing no high challenges for the survival of contemporary life forms. IR derives from natural sources and naturally occurring radioactive materials (NORM), the nuclear industry, medical applications, and as a result of radiation disasters or nuclear tests. In the current review, we discuss modern sources of radioactivity, its direct and indirect effects on different plant species, and the scope of the radiation protection of plants. We present an overview of the molecular mechanisms of radiation responses in plants, which leads to a tempting conjecture of the evolutionary role of IR as a limiting factor for land colonization and plant diversification rates. The hypothesis-driven analysis of available plant genomic data suggests an overall DNA repair gene families’ depletion in land plants compared to ancestral groups, which overlaps with a decrease in levels of radiation exposure on the surface of Earth millions of years ago. The potential contribution of chronic IR as an evolutionary factor in combination with other environmental factors is discussed. Full article

(This article belongs to the Special Issue Effects of Chronic Irradiation in Plants)

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18 pages, 2378 KiB

Open AccessEditor’s ChoiceArticle

Exogenous Melatonin Alters Stomatal Regulation in Tomato Seedlings Subjected to Combined Heat and Drought Stress through Mechanisms Distinct from ABA Signaling

by Nikolaj Bjerring Jensen, Carl-Otto Ottosen and Rong Zhou

Plants 2023, 12(5), 1156; https://doi.org/10.3390/plants12051156 - 3 Mar 2023

Cited by 26 | Viewed by 3450

Abstract

The understanding of stomatal regulation in climate stress is essential for ensuring resilient crops. The investigation of the stomatal regulation in combined heat and drought stress aimed to link effects of exogenous melatonin on stomatal conductance (g_s) and its mechanistic interactions [...] Read more.

The understanding of stomatal regulation in climate stress is essential for ensuring resilient crops. The investigation of the stomatal regulation in combined heat and drought stress aimed to link effects of exogenous melatonin on stomatal conductance (g_s) and its mechanistic interactions with ABA or ROS signaling. Melatonin-treated and non-treated tomato seedlings were subjected to moderate and severe levels of heat (38°C for one or three days) and drought stress (soil relative water content of 50% or 20%) applied individually and in combination. We measured g_s, stomatal anatomy, ABA metabolites and enzymatic ROS scavengers. The stomata in combined stress responded predominantly to heat at soil relative water content (SRWC) = 50% and to drought stress at SRWC = 20%. Drought stress increased ABA levels at severe stress, whereas heat stress caused an accumulation of the conjugated form, ABA glucose ester, at both moderate and severe stress. The melatonin treatment affected g_s and the activity of ROS scavenging enzymes but had no effect on ABA levels. The ABA metabolism and conjugation of ABA might play a role in stomatal opening toward high temperatures. We provide evidence that melatonin increases g_s in combined heat and drought stress, but the effect is not mediated through ABA signaling. Full article

(This article belongs to the Special Issue New Insights of Plants to Combined Stresses)

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23 pages, 2383 KiB

Open AccessEditor’s ChoiceReview

Interactions of Polyamines and Phytohormones in Plant Response to Abiotic Stress

by Natalia Napieraj, Małgorzata Janicka and Małgorzata Reda

Plants 2023, 12(5), 1159; https://doi.org/10.3390/plants12051159 - 3 Mar 2023

Cited by 48 | Viewed by 5981

Abstract

Numerous environmental conditions negatively affect plant production. Abiotic stresses, such as salinity, drought, temperature, and heavy metals, cause damage at the physiological, biochemical, and molecular level, and limit plant growth, development, and survival. Studies have indicated that small amine compounds, polyamines (PAs), play [...] Read more.

Numerous environmental conditions negatively affect plant production. Abiotic stresses, such as salinity, drought, temperature, and heavy metals, cause damage at the physiological, biochemical, and molecular level, and limit plant growth, development, and survival. Studies have indicated that small amine compounds, polyamines (PAs), play a key role in plant tolerance to various abiotic stresses. Pharmacological and molecular studies, as well as research using genetic and transgenic approaches, have revealed the favorable effects of PAs on growth, ion homeostasis, water maintenance, photosynthesis, reactive oxygen species (ROS) accumulation, and antioxidant systems in many plant species under abiotic stress. PAs display a multitrack action: regulating the expression of stress response genes and the activity of ion channels; improving the stability of membranes, DNA, and other biomolecules; and interacting with signaling molecules and plant hormones. In recent years the number of reports indicating crosstalk between PAs and phytohormones in plant response to abiotic stresses has increased. Interestingly, some plant hormones, previously known as plant growth regulators, can also participate in plant response to abiotic stresses. Therefore, the main goal of this review is to summarize the most significant results that represent the interactions between PAs and plant hormones, such as abscisic acid, brassinosteroids, ethylene, jasmonates, and gibberellins, in plants under abiotic stress. The future perspectives for research focusing on the crosstalk between PAs and plant hormones were also discussed. Full article

(This article belongs to the Special Issue Phytohormone-Related Response of Crops to Biotic and Abiotic Stresses)

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21 pages, 3204 KiB

Open AccessEditor’s ChoiceArticle

Almond Tree Adaptation to Water Stress: Differences in Physiological Performance and Yield Responses among Four Cultivar Grown in Mediterranean Environment

by Ana Fernandes de Oliveira, Massimiliano Giuseppe Mameli, Luciano De Pau and Daniela Satta

Plants 2023, 12(5), 1131; https://doi.org/10.3390/plants12051131 - 2 Mar 2023

Cited by 13 | Viewed by 5359

Abstract

Maximizing water use efficiency, yield, and plant survival under drought is a relevant research issue for almond-tree-growing areas worldwide. The intraspecific diversity of this species may constitute a valuable resource to address the resilience and productivity challenges that climate change poses to crop [...] Read more.

Maximizing water use efficiency, yield, and plant survival under drought is a relevant research issue for almond-tree-growing areas worldwide. The intraspecific diversity of this species may constitute a valuable resource to address the resilience and productivity challenges that climate change poses to crop sustainability. A comparative evaluation of physiological and productive performance of four almond varieties: ‘Arrubia’, ‘Cossu’, ‘Texas’, and ‘Tuono’, field-grown in Sardinia, Italy, was performed. A great variability in the plasticity to cope with soil water scarcity and a diverse capacity to adapt to drought and heat stresses during fruit development were highlighted. The two Sardinian varieties, Arrubia and Cossu, showed differences in water stress tolerance, photosynthetic and photochemical activity, and crop yield. ‘Arrubia’ and ‘Texas’ showed greater physiological acclimation to water stress while maintaining higher yields, as compared to the self-fertile ‘Tuono’. The important role of crop load and specific anatomical traits affecting leaf hydraulic conductance and leaf gas exchanges efficiency (i.e., dominant shoot type, leaf size and roughness) was evidenced. The study highlights the importance of characterizing the relationships among almond cultivar traits that affect plant performance under drought in order to better assist planting choices and orchard irrigation management for given environmental contexts. Full article

(This article belongs to the Section Horticultural Science and Ornamental Plants)

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17 pages, 2274 KiB

Open AccessEditor’s ChoiceReview

Ginsenosides and Biotic Stress Responses of Ginseng

by Paul H. Goodwin and Madison A. Best

Plants 2023, 12(5), 1091; https://doi.org/10.3390/plants12051091 - 1 Mar 2023

Cited by 16 | Viewed by 4580

Abstract

Ginsenosides are saponins that possess a sugar moiety attached to a hydrophobic aglycone triterpenoid. They have been widely studied for their various medicinal benefits, such as their neuroprotective and anti-cancer activities, but their role in the biology of ginseng plants has been much [...] Read more.

Ginsenosides are saponins that possess a sugar moiety attached to a hydrophobic aglycone triterpenoid. They have been widely studied for their various medicinal benefits, such as their neuroprotective and anti-cancer activities, but their role in the biology of ginseng plants has been much less widely documented. In the wild, ginsengs are slow-growing perennials with roots that can survive for approximately 30 years; thus, they need to defend themselves against many potential biotic stresses over many decades. Biotic stresses would be a major natural selection pressure and may at least partially explain why ginseng roots expend considerable resources in order to accumulate relatively large amounts of ginsenosides. Ginsenosides may provide ginseng with antimicrobial activity against pathogens, antifeedant activity against insects and other herbivores, and allelopathic activity against other plants. In addition, the interaction of ginseng with pathogenic and non-pathogenic microorganisms and their elicitors may trigger increases in different root ginsenosides and associated gene expression, although some pathogens may be able to suppress this behavior. While not covered in this review, ginsenosides also have roles in ginseng development and abiotic stress tolerance. This review shows that there is considerable evidence supporting ginsenosides as important elements of ginseng’s defense against a variety of biotic stresses. Full article

(This article belongs to the Special Issue Plant Metabolomics: Metabolite Responses to Stress)

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22 pages, 3129 KiB

Open AccessEditor’s ChoiceArticle

Biological Activity of Cupressus sempervirens Essential Oil

by Lucia Galovičová, Natália Čmiková, Marianna Schwarzová, Milena D. Vukic, Nenad L. Vukovic, Przemysław Łukasz Kowalczewski, Ladislav Bakay, Maciej Ireneusz Kluz, Czeslaw Puchalski, Ana D. Obradovic, Miloš M. Matić and Miroslava Kačániová

Plants 2023, 12(5), 1097; https://doi.org/10.3390/plants12051097 - 1 Mar 2023

Cited by 17 | Viewed by 4252

Abstract

The aim of this study was to evaluate the antioxidant, antibiofilm, antimicrobial (in situ and in vitro), insecticidal, and antiproliferative activity of Cupressus sempervirens essential oil (CSEO) obtained from the plant leaf. The identification of the constituents contained in CSEO was also intended [...] Read more.

The aim of this study was to evaluate the antioxidant, antibiofilm, antimicrobial (in situ and in vitro), insecticidal, and antiproliferative activity of Cupressus sempervirens essential oil (CSEO) obtained from the plant leaf. The identification of the constituents contained in CSEO was also intended by using GC and GC/MS analysis. The chemical composition revealed that this sample was dominated by monoterpene hydrocarbons α-pinene, and δ-3-carene. Free radical scavenging ability, performed by using DPPH and ABTS assays, was evaluated as strong. Higher antibacterial efficacy was demonstrated for the agar diffusion method compared to the disk diffusion method. The antifungal activity of CSEO was moderate. When the minimum inhibitory concentrations of filamentous microscopic fungi were determined, we observed the efficacy depending on the concentration used, except for B. cinerea where the efficacy of lower concentration was more pronounced. The vapor phase effect was more pronounced at lower concentrations in most cases. Antibiofilm effect against Salmonella enterica was demonstrated. The relatively strong insecticidal activity was demonstrated with an LC50 value of 21.07% and an LC90 value of 78.21%, making CSEO potentially adequate in the control of agricultural insect pests. Results of cell viability testing showed no effects on the normal MRC-5 cell line, and antiproliferative effects towards MDA-MB-231, HCT-116, JEG-3, and K562 cells, whereas K562 cells were the most sensitive. Based on our results, CSEO could be a suitable alternative against different types of microorganisms as well as suitable for the control of biofilms. Due to its insecticidal properties, it could be used in the control of agricultural insect pests. Full article

(This article belongs to the Special Issue Plant Essential Oil with Biological Activity II)

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13 pages, 1444 KiB

Open AccessEditor’s ChoiceReview

On the Path towards a “Greener” EU: A Mini Review on Flax (Linum usitatissimum L.) as a Case Study

by Panteleimon Stavropoulos, Antonios Mavroeidis, George Papadopoulos, Ioannis Roussis, Dimitrios Bilalis and Ioanna Kakabouki

Plants 2023, 12(5), 1102; https://doi.org/10.3390/plants12051102 - 1 Mar 2023

Cited by 23 | Viewed by 4914

Abstract

Due to the pressures imposed by climate change, the European Union (EU) has been forced to design several initiatives (the Common Agricultural Policy, the European Green Deal, Farm to Fork) to tackle the climate crisis and ensure food security. Through these initiatives, the [...] Read more.

Due to the pressures imposed by climate change, the European Union (EU) has been forced to design several initiatives (the Common Agricultural Policy, the European Green Deal, Farm to Fork) to tackle the climate crisis and ensure food security. Through these initiatives, the EU aspires to mitigate the adverse effects of the climate crisis and achieve collective prosperity for humans, animals, and the environment. The adoption or promotion of crops that would facilitate the attaining of these objectives is naturally of high importance. Flax (Linum usitatissimum L.) is a multipurpose crop with many applications in the industrial, health, and agri-food sectors. This crop is mainly grown for its fibers or its seed and has recently gained increasing attention. The literature suggests that flax can be grown in several parts of the EU, and potentially has a relatively low environmental impact. The aim of the present review is to: (i) briefly present the uses, needs, and utility of this crop and, (ii) assess its potential within the EU by taking into account the sustainability goals the EU has set via its current policies. Full article

(This article belongs to the Special Issue Towards Sustainable Development of Horticulture in a Changing Climate Scenario)

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24 pages, 2741 KiB

Open AccessEditor’s ChoiceArticle

Physiological and Transcriptomic Evaluation of Drought Effect on Own-Rooted and Grafted Grapevine Rootstock (1103P and 101-14MGt)

by Davide Bianchi, Valentina Ricciardi, Carola Pozzoli, Daniele Grossi, Leila Caramanico, Massimo Pindo, Erika Stefani, Alessandro Cestaro, Lucio Brancadoro and Gabriella De Lorenzis

Plants 2023, 12(5), 1080; https://doi.org/10.3390/plants12051080 - 28 Feb 2023

Cited by 13 | Viewed by 2931

Abstract

Grapevines worldwide are grafted onto Vitis spp. rootstocks in order to improve their tolerance to biotic and abiotic stresses. Thus, the response of vines to drought is the result of the interaction between the scion variety and the rootstock genotype. In this work, [...] Read more.

Grapevines worldwide are grafted onto Vitis spp. rootstocks in order to improve their tolerance to biotic and abiotic stresses. Thus, the response of vines to drought is the result of the interaction between the scion variety and the rootstock genotype. In this work, the responses of genotypes to drought were evaluated on 1103P and 101-14MGt plants, own-rooted and grafted with Cabernet Sauvignon, in three different water deficit conditions (80, 50, and 20% soil water content, SWC). Gas exchange parameters, stem water potential, root and leaf ABA content, and root and leaf transcriptomic response were investigated. Under well-watered conditions, gas exchange and stem water potential were mainly affected by the grafting condition, whereas under sever water deficit they were affected by the rootstock genotype. Under severe stress conditions (20% SWC), 1103P showed an “avoidance” behavior. It reduced stomatal conductance, inhibited photosynthesis, increased ABA content in the roots, and closed the stomata. The 101-14MGt maintained a high photosynthetic rate, limiting the reduction of soil water potential. This behavior results in a “tolerance” strategy. An analysis of the transcriptome showed that most of the differentially expressed genes were detected at 20% SWC, and more significantly in roots than in leaves. A core set of genes has been highlighted on the roots as being related to the root response to drought that are not affected by genotype nor grafting. Genes specifically regulated by grafting and genes specifically regulated by genotype under drought conditions have been identified as well. The 1103P, more than the 101-14MGt, regulated a high number of genes in both own-rooted and grafted conditions. This different regulation revealed that 1103P rootstock readily perceived the water scarcity and rapidly faced the stress, in agreement with its avoidance strategy. Full article

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

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18 pages, 2008 KiB

Open AccessEditor’s ChoiceArticle

Chemical Composition and Biological Activities of Eucalyptus globulus Essential Oil

by Natália Čmiková, Lucia Galovičová, Marianna Schwarzová, Milena D. Vukic, Nenad L. Vukovic, Przemysław Łukasz Kowalczewski, Ladislav Bakay, Maciej Ireneusz Kluz, Czeslaw Puchalski and Miroslava Kačániová

Plants 2023, 12(5), 1076; https://doi.org/10.3390/plants12051076 - 28 Feb 2023

Cited by 41 | Viewed by 9329

Abstract

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and [...] Read more.

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and insecticidal activity. The chemical composition was identified using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The main components of EGEO were 1,8-cineole (63.1%), p-cimene (7.7%), a-pinene (7.3%), and a-limonene (6.9%). Up to 99.2% of monoterpenes were present. The antioxidant potential of essential oil and results indicate that 10 μL of this sample can neutralize 55.44 ± 0.99% of ABTS^•+, which is equivalent to 3.22 ± 0.01 TEAC. Antimicrobial activity was determined via two methods: disk diffusion and minimum inhibitory concentration. The best antimicrobial activity was shown against C. albicans (14.00 ± 1.00 mm) and microscopic fungi (11.00 ± 0.00 mm–12.33 ± 0.58 mm). The minimum inhibitory concentration showed the best results against C. tropicalis (MIC 50 2.93 µL/mL, MIC 90 3.17 µL/mL). The antibiofilm activity of EGEO against biofilm-forming P. flourescens was also confirmed in this study. The antimicrobial activity in situ, i.e., in the vapor phase, was significantly stronger than in the contact application. Insecticidal activity was also tested and at concentrations of 100%, 50%, and 25%; the EGEO killed 100% of O. lavaterae individuals. EGEO was comprehensively investigated in this study and information regarding the biological activities and chemical composition of the essential oil of Eucalyptus globulus was expanded. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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15 pages, 2521 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Two Organic Soil Amendments, Biochar and Insect Frass Fertilizer, on Shoot Growth of Cereal Seedlings

by Aaron Carroll, Mark Fitzpatrick and Simon Hodge

Plants 2023, 12(5), 1071; https://doi.org/10.3390/plants12051071 - 27 Feb 2023

Cited by 18 | Viewed by 4709

Abstract

To mitigate the environmental harm associated with high-input agriculture, arable farmers are increasingly required to maintain productivity while reducing inputs of synthetic fertilizers. Thus, a diverse range of organic products are now being investigated in terms of their value as alternative fertilizers and [...] Read more.

To mitigate the environmental harm associated with high-input agriculture, arable farmers are increasingly required to maintain productivity while reducing inputs of synthetic fertilizers. Thus, a diverse range of organic products are now being investigated in terms of their value as alternative fertilizers and soil amendments. This study used a series of glasshouse trials to investigate the effects of an insect frass-based fertilizer derived from black soldier fly waste [HexaFrass™, Meath, Ireland] and biochar on four cereals grown in Ireland (barley, oats, triticale, spelt) as animal feed and for human consumption. In general, the application of low quantities of HexaFrass™ resulted in significant increases in shoot growth in all four cereal species, along with increased foliage concentrations of NPK and SPAD levels (a measure of chlorophyll density). These positive effects of HexaFrass™ on shoot growth were observed, however, only when a potting mix with low basal nutrients was used. Additionally, excessive application of HexaFrass™ resulted in reduced shoot growth and, in some cases, seedling mortality. The application of finely ground or crushed biochar produced from four different feedstocks (Ulex, Juncus, woodchip, olive stone) had no consistent positive or negative effects on cereal shoot growth. Overall, our results indicate that insect frass-based fertilizers have good potential in low-input, organic, or regenerative cereal production systems. Based on our results, biochar appears to have less potential as a plant growth promoting product, but could be used as a tool for lowering whole-farm carbon budgets by providing a simplistic means of storing carbon in farm soils. Full article

(This article belongs to the Section Plant–Soil Interactions)

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22 pages, 1407 KiB

Open AccessEditor’s ChoiceReview

Beyond Cleansing: Ecosystem Services Related to Phytoremediation

by Werther Guidi Nissim, Stefano Castiglione, Francesco Guarino, Maria Chiara Pastore and Massimo Labra

Plants 2023, 12(5), 1031; https://doi.org/10.3390/plants12051031 - 24 Feb 2023

Cited by 35 | Viewed by 4476

Abstract

Phytotechnologies used for cleaning up urban and suburban polluted soils (i.e., brownfields) have shown some weakness in the excessive extent of the timeframe required for them to be effectively operating. This bottleneck is due to technical constraints, mainly related to both the nature [...] Read more.

Phytotechnologies used for cleaning up urban and suburban polluted soils (i.e., brownfields) have shown some weakness in the excessive extent of the timeframe required for them to be effectively operating. This bottleneck is due to technical constraints, mainly related to both the nature of the pollutant itself (e.g., low bio-availability, high recalcitrance, etc.) and the plant (e.g., low pollution tolerance, low pollutant uptake rates, etc.). Despite the great efforts made in the last few decades to overcome these limitations, the technology is in many cases barely competitive compared with conventional remediation techniques. Here, we propose a new outlook on phytoremediation, where the main goal of decontaminating should be re-evaluated, considering additional ecosystem services (ESs) related to the establishment of a new vegetation cover on the site. The aim of this review is to raise awareness and stress the knowledge gap on the importance of ES associated with this technique, which can make phytoremediation a valuable tool to boost an actual green transition process in planning urban green spaces, thereby offering improved resilience to global climate change and a higher quality of life in cities. This review highlights that the reclamation of urban brownfields through phytoremediation may provide several regulating (i.e., urban hydrology, heat mitigation, noise reduction, biodiversity, and CO₂ sequestration), provisional (i.e., bioenergy and added-value chemicals), and cultural (i.e., aesthetic, social cohesion, and health) ESs. Although future research should specifically be addressed to better support these findings, acknowledging ES is crucial for an exhaustive evaluation of phytoremediation as a sustainable and resilient technology. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

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12 pages, 11777 KiB

Open AccessEditor’s ChoiceArticle

Surfactin and Spo0A-Dependent Antagonism by Bacillus subtilis Strain UD1022 against Medicago sativa Phytopathogens

by Amanda Rosier, Maude Pomerleau, Pascale B. Beauregard, Deborah A. Samac and Harsh P. Bais

Plants 2023, 12(5), 1007; https://doi.org/10.3390/plants12051007 - 23 Feb 2023

Cited by 14 | Viewed by 4489

Abstract

Plant growth-promoting rhizobacteria (PGPR) such as the root colonizers Bacillus spp. may be ideal alternatives to chemical crop treatments. This work sought to extend the application of the broadly active PGPR UD1022 to Medicago sativa (alfalfa). Alfalfa is susceptible to many phytopathogens resulting [...] Read more.

Plant growth-promoting rhizobacteria (PGPR) such as the root colonizers Bacillus spp. may be ideal alternatives to chemical crop treatments. This work sought to extend the application of the broadly active PGPR UD1022 to Medicago sativa (alfalfa). Alfalfa is susceptible to many phytopathogens resulting in losses of crop yield and nutrient value. UD1022 was cocultured with four alfalfa pathogen strains to test antagonism. We found UD1022 to be directly antagonistic toward Collectotrichum trifolii, Ascochyta medicaginicola (formerly Phoma medicaginis), and Phytophthora medicaginis, and not toward Fusarium oxysporum f. sp. medicaginis. Using mutant UD1022 strains lacking genes in the nonribosomal peptide (NRP) and biofilm pathways, we tested antagonism against A. medicaginicola StC 306-5 and P. medicaginis A2A1. The NRP surfactin may have a role in the antagonism toward the ascomycete StC 306-5. Antagonism toward A2A1 may be influenced by B. subtilis biofilm pathway components. The B. subtilis central regulator of both surfactin and biofilm pathways Spo0A was required for the antagonism of both phytopathogens. The results of this study indicate that the PGPR UD1022 would be a good candidate for further investigations into its antagonistic activities against C. trifolii, A. medicaginicola, and P. medicaginis in plant and field studies. Full article

(This article belongs to the Special Issue Plant Bioprotection)

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12 pages, 888 KiB

Open AccessEditor’s ChoiceReview

Salicylic Acid and Mobile Regulators of Systemic Immunity in Plants: Transport and Metabolism

by Tae-Jin Kim and Gah-Hyun Lim

Plants 2023, 12(5), 1013; https://doi.org/10.3390/plants12051013 - 23 Feb 2023

Cited by 30 | Viewed by 7148

Abstract

Systemic acquired resistance (SAR) occurs when primary infected leaves produce several SAR-inducing chemical or mobile signals that are transported to uninfected distal parts via apoplastic or symplastic compartments and activate systemic immunity. The transport route of many chemicals associated with SAR is unknown. [...] Read more.

Systemic acquired resistance (SAR) occurs when primary infected leaves produce several SAR-inducing chemical or mobile signals that are transported to uninfected distal parts via apoplastic or symplastic compartments and activate systemic immunity. The transport route of many chemicals associated with SAR is unknown. Recently, it was demonstrated that pathogen-infected cells preferentially transport salicylic acid (SA) through the apoplasts to uninfected areas. The pH gradient and deprotonation of SA may lead to apoplastic accumulation of SA before it accumulates in the cytosol following pathogen infection. Additionally, SA mobility over a long distance is essential for SAR, and transpiration controls the partitioning of SA into apoplasts and cuticles. On the other hand, glycerol-3-phosphate (G3P) and azelaic acid (AzA) travel via the plasmodesmata (PD) channel in the symplastic route. In this review, we discuss the role of SA as a mobile signal and the regulation of SA transport in SAR. Full article

(This article belongs to the Special Issue Systemic Signaling during Abiotic Stress in Plants)

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21 pages, 3349 KiB

Open AccessEditor’s ChoiceArticle

Yield and Grain Quality of Common Wheat (Triticum aestivum L.) Depending on the Different Farming Systems (Organic vs. Integrated vs. Conventional)

by Katarzyna Mitura, Grażyna Cacak-Pietrzak, Beata Feledyn-Szewczyk, Tomasz Szablewski and Marcin Studnicki

Plants 2023, 12(5), 1022; https://doi.org/10.3390/plants12051022 - 23 Feb 2023

Cited by 53 | Viewed by 9553

Abstract

Genotype (cultivar), soil and climatic conditions, the agrotechnology used, and the interaction of the factors mentioned play a key role in the yield and quality of wheat grain. Currently, the European Union recommends the balanced use of mineral fertilisers and plant protection products [...] Read more.

Genotype (cultivar), soil and climatic conditions, the agrotechnology used, and the interaction of the factors mentioned play a key role in the yield and quality of wheat grain. Currently, the European Union recommends the balanced use of mineral fertilisers and plant protection products in agricultural production (integrated production) or the use of only natural production methods (organic production). The aim of the study was to compare the yield and grain quality of four spring common wheat cultivars Harenda, Kandela, Mandaryna, and Serenada, grown under three farming systems: organic (ORG), integrated (INT), and conventional (CONV). A three-year field experiment was conducted between 2019 and 2021 at the Osiny Experimental Station (Poland, 51°27′ N; 22°2′ E). The results showed that significantly the highest wheat grain yield (GY) was obtained at INT, while the lowest was obtained at ORG. The physicochemical and rheological characteristics of the grain were significantly influenced by the cultivar factor and, with the exception of 1000 grain weight (TGW) and ash content (AC), by the farming system. There were also numerous interactions between the cultivar and farming systems, which suggests different performances of cultivars and, in fact, that some cultivars are better or worse suited to different production systems. The exceptions were protein content (PC) and falling number (FN), which were significantly highest in grain with CONV and lowest in grain with ORG farming systems. Full article

(This article belongs to the Special Issue Agricultural Water and Fertilizer Management for Crop Production)

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17 pages, 893 KiB

Open AccessEditor’s ChoiceReview

Abscisic-Acid-Regulated Responses to Alleviate Cadmium Toxicity in Plants

by Yuquan Zhao, Jiaqi Wang, Wei Huang, Dawei Zhang, Jinfeng Wu, Bao Li, Mei Li, Lili Liu and Mingli Yan

Plants 2023, 12(5), 1023; https://doi.org/10.3390/plants12051023 - 23 Feb 2023

Cited by 22 | Viewed by 3653

Abstract

High levels of cadmium (Cd) in soil can cause crop yield reduction or death. Cadmium accumulation in crops affects human and animal health as it passes through the food chain. Therefore, a strategy is needed to enhance the tolerance of crops to this [...] Read more.

High levels of cadmium (Cd) in soil can cause crop yield reduction or death. Cadmium accumulation in crops affects human and animal health as it passes through the food chain. Therefore, a strategy is needed to enhance the tolerance of crops to this heavy metal or reduce its accumulation in crops. Abscisic acid (ABA) plays an active role in plants’ response to abiotic stress. The application of exogenous ABA can reduce Cd accumulation in shoots of some plants and enhance the tolerance of plants to Cd; therefore, ABA may have good application prospects. In this paper, we reviewed the synthesis and decomposition of ABA, ABA-mediated signal transduction, and ABA-mediated regulation of Cd-responsive genes in plants. We also introduced physiological mechanism underlying Cd tolerance because of ABA. Specifically, ABA affects metal ion uptake and transport by influencing transpiration and antioxidant systems, as well as by affecting the expression of metal transporter and metal chelator protein genes. This study may provide a reference for further research on the physiological mechanism of heavy metal tolerance in plants. Full article

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18 pages, 4830 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Analysis of the Rhododendron AP2/ERF Gene Family: Identification and Expression Profiles in Response to Cold, Salt and Drought Stress

by Zhenhao Guo, Lisi He, Xiaobo Sun, Chang Li, Jiale Su, Huimin Zhou and Xiaoqing Liu

Plants 2023, 12(5), 994; https://doi.org/10.3390/plants12050994 - 22 Feb 2023

Cited by 24 | Viewed by 3153

Abstract

The AP2/ERF gene family is one of the most conserved and important transcription factor families mainly occurring in plants with various functions in regulating plant biological and physiological processes. However, little comprehensive research has been conducted on the AP2/ERF gene family in Rhododendron [...] Read more.

The AP2/ERF gene family is one of the most conserved and important transcription factor families mainly occurring in plants with various functions in regulating plant biological and physiological processes. However, little comprehensive research has been conducted on the AP2/ERF gene family in Rhododendron (specifically, Rhododendron simsii), an important ornamental plant. The existing whole-genome sequence of Rhododendron provided data to investigate the AP2/ERF genes in Rhododendron on a genome-wide scale. A total of 120 Rhododendron AP2/ERF genes were identified. The phylogenetic analysis showed that RsAP2 genes were classified into five main subfamilies, AP2, ERF, DREB, RAV and soloist. Cis-acting elements involving plant growth regulators, response to abiotic stress and MYB binding sites were detected in the upstream sequences of RsAP2 genes. A heatmap of RsAP2 gene expression levels showed that these genes had different expression patterns in the five developmental stages of Rhododendron flowers. Twenty RsAP2 genes were selected for quantitative RT-PCR experiments to clarify the expression level changes under cold, salt and drought stress treatments, and the results showed that most of the RsAP2 genes responded to these abiotic stresses. This study generated comprehensive information on the RsAP2 gene family and provides a theoretical basis for future genetic improvement. Full article

(This article belongs to the Special Issue Molecular Biology of Ornamental Plants)

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21 pages, 1344 KiB

Open AccessEditor’s ChoiceReview

Health-Promoting Properties and Potential Application in the Food Industry of Citrus medica L. and Citrus × clementina Hort. Ex Tan. Essential Oils and Their Main Constituents

by Rosa Tundis, Jianbo Xiao, Ana Sanches Silva, Filipa Carreiró and Monica Rosa Loizzo

Plants 2023, 12(5), 991; https://doi.org/10.3390/plants12050991 - 21 Feb 2023

Cited by 25 | Viewed by 5019

Abstract

Citrus is an important genus in the Rutaceae family, with high medicinal and economic value, and includes important crops such as lemons, orange, grapefruits, limes, etc. The Citrus species is rich sources of carbohydrates, vitamins, dietary fibre, and phytochemicals, mainly including limonoids, flavonoids, [...] Read more.

Citrus is an important genus in the Rutaceae family, with high medicinal and economic value, and includes important crops such as lemons, orange, grapefruits, limes, etc. The Citrus species is rich sources of carbohydrates, vitamins, dietary fibre, and phytochemicals, mainly including limonoids, flavonoids, terpenes, and carotenoids. Citrus essential oils (EOs) consist of several biologically active compounds mainly belonging to the monoterpenes and sesquiterpenes classes. These compounds have demonstrated several health-promoting properties such as antimicrobial, antioxidant, anti-inflammatory, and anti-cancer properties. Citrus EOs are obtained mainly from peels, but also from leaves and flowers, and are widely used as flavouring ingredients in food, cosmetics, and pharmaceutical products. This review focused on the composition and biological properties of the EOs of Citrus medica L. and Citrus clementina Hort. Ex Tan and their main constituents, limonene, γ-terpinene, myrcene, linalool, and sabinene. The potential applications in the food industry have been also described. All the articles available in English or with an abstract in English were extracted from different databases such as PubMed, SciFinder, Google Scholar, Web of Science, Scopus, and Science Direct. Full article

(This article belongs to the Collection Essential Oils of Plants (Chemical Composition, Variation and Properties))

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23 pages, 1827 KiB

Open AccessEditor’s ChoiceArticle

Characterization, Antioxidant Potential, and Pharmacokinetics Properties of Phenolic Compounds from Native Australian Herbs and Fruits

by Akhtar Ali, Jeremy J. Cottrell and Frank R. Dunshea

Plants 2023, 12(5), 993; https://doi.org/10.3390/plants12050993 - 21 Feb 2023

Cited by 22 | Viewed by 4025

Abstract

In recent decades, plant bioactive phenolic compounds gained much attention due to their various health benefits. Therefore, this study aimed to analyze native Australian river mint (Mentha australis), bush mint (Mentha satureioides), sea parsley (Apium prostratum), and bush [...] Read more.

In recent decades, plant bioactive phenolic compounds gained much attention due to their various health benefits. Therefore, this study aimed to analyze native Australian river mint (Mentha australis), bush mint (Mentha satureioides), sea parsley (Apium prostratum), and bush tomatoes (Solanum centrale) for their bioactive metabolites, antioxidant potential, and pharmacokinetics properties. LC-ESI-QTOF-MS/MS was applied to elucidate these plants’ composition, identification, and quantification of phenolic metabolites. This study tentatively identified 123 phenolic compounds (thirty-five phenolic acids, sixty-seven flavonoids, seven lignans, three stilbenes, and eleven other compounds). Bush mint was identified with the highest total phenolic content (TPC—57.70 ± 4.57 mg GAE/g), while sea parsley contained the lowest total phenolic content (13.44 ± 0.39 mg GAE/g). Moreover, bush mint was also identified with the highest antioxidant potential compared to other herbs. Thirty-seven phenolic metabolites were semi-quantified, including rosmarinic acid, chlorogenic acid, sagerinic acid, quinic acid, and caffeic acid, which were abundant in these selected plants. The most abundant compounds’ pharmacokinetics properties were also predicted. This study will develop further research to identify these plants’ nutraceutical and phytopharmaceutical potential. Full article

(This article belongs to the Special Issue Phytochemical Profiles of Plant Materials: From Extracts to Added Value Ingredients)

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18 pages, 2008 KiB

Open AccessEditor’s ChoiceArticle

Influence of Drought and Heat Stress on Mineral Content, Antioxidant Activity and Bioactive Compound Accumulation in Four African Amaranthus Species

by Mmbulaheni Happiness Netshimbupfe, Jacques Berner, Frank Van Der Kooy, Olakunle Oladimeji and Chrisna Gouws

Plants 2023, 12(4), 953; https://doi.org/10.3390/plants12040953 - 20 Feb 2023

Cited by 13 | Viewed by 2842

Abstract

Drought and heat stress is known to influence the accumulation of mineral content, antioxidant activity, phenolics, flavonoids and other bioactive compounds in many tolerant leafy vegetables. Amaranthus plants can tolerate adverse weather conditions, especially drought and heat. Therefore, evaluating the influence of drought [...] Read more.

Drought and heat stress is known to influence the accumulation of mineral content, antioxidant activity, phenolics, flavonoids and other bioactive compounds in many tolerant leafy vegetables. Amaranthus plants can tolerate adverse weather conditions, especially drought and heat. Therefore, evaluating the influence of drought and heat stress on commercially and medically important crop species like Amaranthus is important to grow the crop for optimal nutritional and medicinal properties. This study investigated the influence of drought and heat stress and a combination of both on the accumulation of phenolic and flavonoid compounds and the antioxidant capacity of African Amaranthus caudatus, A. hypochondriacus, A. cruentus and A. spinosus. Phenolic and flavonoid compounds were extracted with methanol and aqueous solvents and were quantified using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Caffeic acid was the main phenolic compound identified in aqueous extracts of A. caudatus and A. hypochondriacus. Rutin was the most abundant flavonoid compound in all the Amaranthus species tested, with the highest concentration found in A. caudatus. The results suggest a strong positive, but species and compound-specific effect of drought and heat stress on bioactive compounds accumulation. We concluded that heat stress at 40 °C under well-watered conditions and combined drought and heat stress (at 30 °C and 35 °C) appeared to induce the accumulation of caffeic acid and rutin. Hence, cultivation of these species in semi-arid and arid areas is feasible. Full article

(This article belongs to the Special Issue Plant Ecophysiological Adaptation to Environmental Stress)

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35 pages, 835 KiB

Open AccessEditor’s ChoiceReview

Contribution of Biofertilizers to Pulse Crops: From Single-Strain Inoculants to New Technologies Based on Microbiomes Strategies

by Gustavo Ribeiro Xavier, Ederson da Conceição Jesus, Anelise Dias, Marcia Reed Rodrigues Coelho, Yulimar Castro Molina and Norma Gouvêa Rumjanek

Plants 2023, 12(4), 954; https://doi.org/10.3390/plants12040954 - 20 Feb 2023

Cited by 16 | Viewed by 5933

Abstract

Pulses provide distinct health benefits due to their low fat content and high protein and fiber contents. Their grain production reaches approximately 93,210 × 10³ tons per year. Pulses benefit from the symbiosis with atmospheric N₂-fixing bacteria, which increases productivity [...] Read more.

Pulses provide distinct health benefits due to their low fat content and high protein and fiber contents. Their grain production reaches approximately 93,210 × 10³ tons per year. Pulses benefit from the symbiosis with atmospheric N₂-fixing bacteria, which increases productivity and reduces the need for N fertilizers, thus contributing to mitigation of environmental impact mitigation. Additionally, the root region harbors a rich microbial community with multiple traits related to plant growth promotion, such as nutrient increase and tolerance enhancement to abiotic or biotic stresses. We reviewed the eight most common pulses accounting for almost 90% of world production: common beans, chickpeas, peas, cowpeas, mung beans, lentils, broad beans, and pigeon peas. We focused on updated information considering both single-rhizobial inoculation and co-inoculation with plant growth-promoting rhizobacteria. We found approximately 80 microbial taxa with PGPR traits, mainly Bacillus sp., B. subtilis, Pseudomonas sp., P. fluorescens, and arbuscular mycorrhizal fungi, and that contributed to improve plant growth and yield under different conditions. In addition, new data on root, nodule, rhizosphere, and seed microbiomes point to strategies that can be used to design new generations of biofertilizers, highlighting the importance of microorganisms for productive pulse systems. Full article

(This article belongs to the Special Issue Interactions between Plants and Soil Microorganisms)

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24 pages, 2201 KiB

Open AccessEditor’s ChoiceReview

Persimmon Leaves: Nutritional, Pharmaceutical, and Industrial Potential—A Review

by Abul Hossain and Fereidoon Shahidi

Plants 2023, 12(4), 937; https://doi.org/10.3390/plants12040937 - 18 Feb 2023

Cited by 26 | Viewed by 6530

Abstract

Persimmon is a delicious fruit, and its leaves are considered a valuable ingredient in food, beverage, pharmaceutical, and cosmetic sectors. Traditionally, persimmon leaves (PL) are used as a functional tea in Asian culture to cure different ailments, and are also incorporated into various [...] Read more.

Persimmon is a delicious fruit, and its leaves are considered a valuable ingredient in food, beverage, pharmaceutical, and cosmetic sectors. Traditionally, persimmon leaves (PL) are used as a functional tea in Asian culture to cure different ailments, and are also incorporated into various food and cosmeceutical products as a functional ingredient. PL mainly contain flavonoids, terpenoids, and polysaccharides, along with other constituents such as carotenoids, organic acids, chlorophylls, vitamin C, and minerals. The major phenolic compounds in PL are proanthocyanidins, quercetin, isoquercetin, catechin, flavonol glucosides, and kaempferol. Meanwhile, ursolic acid, rotungenic acid, barbinervic acid, and uvaol are the principal terpenoids. These compounds demonstrate a wide range of pharmacological activities, including antioxidant, anticancer, antihypertensive, antidiabetic, anti-obesity, anti-tyrosinase, antiallergic, and antiglaucoma properties. This review summarizes the latest information on PL, mainly distribution, traditional uses, industrial potential, and bioactive compounds, as well as their potential action mechanisms in exhibiting biological activities. In addition, the effect of seasonality and geographical locations on the content and function of these biomolecules are discussed. Full article

(This article belongs to the Special Issue Bioactive Compounds from Plants-Based Functional Foods)

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15 pages, 1148 KiB

Open AccessEditor’s ChoiceArticle

Isolation and Screening of Antagonistic Endophytes against Phytophthora infestans and Preliminary Exploration on Anti-oomycete Mechanism of Bacillus velezensis 6-5

by Jiaomei Zhang, Xiaoqing Huang, Yuqin Hou, Xiangning Xia, Zhiming Zhu, Airong Huang, Shun Feng, Peihua Li, Lei Shi and Pan Dong

Plants 2023, 12(4), 909; https://doi.org/10.3390/plants12040909 - 17 Feb 2023

Cited by 13 | Viewed by 3662

Abstract

Phytophthora infestans, the notorious pathogen of potato late blight, leads to a severe decline in potato yields and even harvest failure. We isolated 201 endophytic isolates from healthy root tissues of potatoes, among which 41 showed strong antagonistic activity against P. infestans [...] Read more.

Phytophthora infestans, the notorious pathogen of potato late blight, leads to a severe decline in potato yields and even harvest failure. We isolated 201 endophytic isolates from healthy root tissues of potatoes, among which 41 showed strong antagonistic activity against P. infestans. Further, the tolerance to stress and the potential application against potato late blight of these antagonistic isolates were tested. Most of them were extremely tolerant to stresses such as acid–alkali, temperature, UV, salt, and heavy metal stress. However, some antagonistic isolates with excellent stress tolerance might be pathogenic to potatoes. Combining the screening results, a total of 14 endophytes had excellent comprehensive performance in all the tests. In this paper, the endophyte 6-5 was selected among them for the preliminary exploration of the anti-oomycete mechanism. Analysis of the 16S rDNA sequence revealed that 6-5 had a high homology to the corresponding sequence of Bacillus velezensis (99.72%) from the NCBI database. Endophyte 6-5 significantly inhibited the mycelial growth of P. infestans, with an inhibition rate of over 90% in vitro assays, and deformed the hyphal phenotype of P. infestans. In addition, endophyte 6-5 could secrete protease and cellulase, and produce antagonistic substances with high thermal stability, which might be helpful to its antagonistic activity against P. infestans. Furthermore, it was demonstrated that 6-5 had the ability to improve the resistance of potato tubers to late blight. In short, our study described the process of isolating and screening endophytes with antagonistic activity against P. infestans from potato roots, and further explored the potential of biocontrol candidate strain 6-5 in potato late blight control. Full article

(This article belongs to the Special Issue Biological Control of Plant Diseases Caused by Pathogenic Microorganisms)

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21 pages, 10449 KiB

Open AccessEditor’s ChoiceArticle

Exogenous Proline Enhances Systemic Defense against Salt Stress in Celery by Regulating Photosystem, Phenolic Compounds, and Antioxidant System

by Yanqiang Gao, Jing Zhang, Cheng Wang, Kangning Han, Lixia Hu, Tianhang Niu, Yan Yang, Youlin Chang and Jianming Xie

Plants 2023, 12(4), 928; https://doi.org/10.3390/plants12040928 - 17 Feb 2023

Cited by 32 | Viewed by 2848

Abstract

This study aimed to explore how exogenous proline induces salinity tolerance in celery. We analyzed the effects of foliar spraying with 0.3 mM proline on celery growth, photosystem, phenolic compounds, and antioxidant system under salt stress (100 mM NaCl), using no salt stress [...] Read more.

This study aimed to explore how exogenous proline induces salinity tolerance in celery. We analyzed the effects of foliar spraying with 0.3 mM proline on celery growth, photosystem, phenolic compounds, and antioxidant system under salt stress (100 mM NaCl), using no salt stress and no proline spraying as control. The results showed that proline-treated plants exhibited a significant increase in plant biomass due to improved growth physiology, supported by gas exchange parameters, chlorophyll fluorescence, and Calvin cycle enzyme activity (Ketosasaccharide-1,5-diphosphate carboxylase and Fructose-1,6-diphosphate aldolase) results. Also, proline spraying significantly suppressed the increase in relative conductivity and malondialdehyde content caused by salt stress, suggesting a reduction in biological membrane damage. Moreover, salt stress resulted in hydrogen peroxide, superoxide anions and 4-coumaric acid accumulation in celery, and their contents were reduced after foliar spraying of proline. Furthermore, proline increased the activity of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) and the content of non-enzymatic antioxidants (reduced ascorbic acid, glutathione, caffeic acid, chlorogenic acid, total phenolic acids, and total flavonoids). Additionally, proline increased the activity of key enzymes (ascorbate oxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase) in the ascorbic acid–glutathione cycle, activating it to counteract salt stress. In summary, exogenous proline promoted celery growth under salt stress, enhanced photosynthesis, increased total phenolic acid and flavonoid contents, and improved antioxidant capacity, thereby improving salt tolerance in celery. Full article

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

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