Plant Stress最新文献

The Abiotic Stress Gene (Asg) family, unique to plants, includes members with the DUF1005 domain of unknown function (DUFs). Although earlier studies have associated members of the Asg gene family and various aspects of plant growth, development, and reactions to abiotic stress, their precise biological roles and underlying mechanisms are not yet well understood. This research found that Asg2 functions not only in regulating root development but also serves as an inhibitor in how the plant responds to salt stress. Overexpression of Asg2 enhances primary root elongation, while gene-edited mutants display the opposite effect. Under salt stress conditions, Arabidopsis lines with increased Asg2 expression exhibit inhibited primary root elongation, reduced seed germination rates, and heightened sensitivity of leaves and seedlings to salt stress. These changes coincide with increased electrolyte leakage, reduced chlorophyll content, decreased antioxidant enzyme activity, and elevated levels of reactive oxygen species (ROS). Transcriptomic analysis revealed that overexpression of Asg2 under salt stress leads to the downregulation of stress resistance genes, thereby increasing sensitivity to salt stress. In conclusion, this research emphasizes the important function of the Asg gene in influencing salt tolerance, providing a foundational framework and genetic resource for comprehending how plants respond to salt stress.

Drought is one of the most detrimental stresses that severely constrains plant growth and productivity. Although Chinese chive (Allium tuberosum Rottler) is a vegetable species that is cultivated and consumed worldwide, few studies have investigated how this species responds to drought. In this study, we conducted transcriptomics, metabolomics, and proteomics analyses on chive seedlings exposed to different water availability conditions (mild drought, moderate drought, severe drought, and re-watering) and found that the accumulation of flavonoids in chive leaves was substantially altered under drought stress. Gene co-expression regulatory network analysis, conducted by integrating transcriptome and metabolome data, revealed a chive R2R3-MYB transcription factor, AtuMYB306, as a central regulator of flavonoid synthesis. Overexpression of AtuMYB306 significantly improved osmotic stress tolerance and enhanced flavonoid content in Arabidopsis. We further demonstrated that AtuMYB306 directly binds to the promoters of three flavonoid biosynthetic genes (Atu4CL, AtuF3H, and AtuF3’H) and activates their expression. These results suggest that AtuMYB306 improves drought tolerance in Chinese chive by enhancing flavonoid biosynthesis to scavenge reactive oxygen species (ROS) generated under water-deficit conditions. Thus, our findings provide evidence that AtuMYB306 playing a pivotal role in improving drought resistance in Chinese chive.

Moisture stress poses a significant threat to global agriculture, compromising crop yields and food security. In the quest for sustainable solutions, endophytic microorganisms have emerged as promising candidates for enhancing plant resilience to drought. The study's primary goal was to analyse the significance of bacterial endophytes, both rhizobial and passenger endophytes, in alleviating the effects of moisture stress. Here, PEG 6000 was used to test the drought endurance of the ten identified rhizobial and passenger endophytes. Rhizobium pusense S6R2, Enterobacter cloacae S23 and Bacillus tequilensis NBB13 were selected as best performing endophytes as they showed high tolerance of poly ethylene glycol (PEG) and maximum plant growth promoting traits like Indole Acetic Acid, exopolysaccharide production, biofilm formation, 1-aminocyclopropane1-carboxylate (ACC) deaminase activity, siderophore, zinc and phosphorous solubilisation even in PEG induced moisture stress condition. Metabolite analysis revealed that twenty-four significant compounds mostly belong to fatty acyls, amino acids, peptides, polyketides, and benzenoids were found in the root exudates of groundnut treated with endophytes. The best-performing endophytes were used in a pot culture experiment, with groundnut as the test crop. The current study found that co-inoculation of Rhizobium pusense S6R2 and Enterobacter cloacae S23 significantly increased nodule number, growth, photosynthetic pigment, anti-oxidant enzymes, and osmolyte under moisture stressed conditions when compared to other treatments. As a result, co-inoculation of Rhizobium and entophytic bacteria may be recommended as a bio-inoculant for groundnut for moisture stress alleviation after confirming the results in field evaluation.

The cuticle serves as a crucial protective barrier for plant survival, and recent studies have highlighted the essential roles of nonspecific lipid transfer proteins (nsLTPs) in cuticle formation. However, the specific function of nsLTPs in the rice leaf cuticle remains unclear. In this study, we functionally characterized OsLTPG22, a G-type nsLTP with a signal peptide (SP) domain and a glycosylphosphatidylinositol (GPI) anchor region. Mutation in OsLTPG22 led to a reduction in cuticular wax abundance, increased leaf epidermal permeability, and higher drought sensitivity in seedlings. OsLTPG22 was widely expressed in various tissues and exhibited distinct polar localization to the aerial surface of epidermal cells in expanding leaves. OsLTPG22 binds lipids and localizes to the plasma membrane. Protein truncation experiments demonstrated that OsLTPG22’s polar localization was regulated by the SP domain, while both the SP domain and GPI anchor region regulated OsLTPG22’s plasma membrane localization. This work provides genetic and cytological evidence for OsLTPG22’s role in leaf cuticle formation and drought response, enhancing our understanding of nsLTP function and offering insights for breeding drought-resistant crops.

Capsicum annuum varieties are highly sensitive to drought. Under water stress conditions, these can show yield losses of up to 70 %. Due to the above, this work proposes a novel approach to obtain estimators of drought stress based on linear regression models for morpho-physiological and biochemical variables in jalapeño pepper (C. annuum cv. jalapeno M), bell pepper (C. annuum cv. california wonder), and serrano pepper (C. annnuum cv. serrano tampiqueno). Jalapeno pepper plants were grown for 69 days under permanent water deficit conditions at 40, 60, 80 % and 100 % of field capacity (FC) (100 % FC as control). Throughout the crop cycle, we monitored the plant's height and weight, basal stem diameter, transpiration, photosynthesis, stomatal conductance, NDVI, and proline. This monitoring allowed us to obtain linear regression models from the accumulated values for these variables, from which the slope values (β) were used as estimators of drought stress using the interval estimation method, in the same way, this method was used to estimate water status in bell pepper and serrano pepper. For bell pepper, drought levels of 40, 60, 80 and 100 % FC were imposed for 12 days and serrano pepper 60 and 100 % FC for 63 days. The results showed that this method can be used to estimate drought stress in jalapeno pepper for all the irrigation levels through photosynthesis and NDVI and can be applied for bell pepper and serrano pepper using stem diameter and plant height, and in the case of serrano pepper, NDVI showed adequate results. Also, this work establishes the relationship between the jalapeno pepper responses (morpho-physiological and biochemical) to drought stress during vegetative, flowering, and fruiting stages through a Principal Component Analysis (PCA). The PCA found that interaction among morphological, physiological, and biochemical responses change concerning the phenological stage of the plant. The results suggested several direct and inverse relationships between the variables and showed that drought can be described by stomatal conductance during any phenological stage of the crop. In parallel, the proline content, NDVI and plant height can also describe drought stress during the vegetative and flowering stages. This research is the first to apply this methodology to drought stress estimation in jalapeno, bell pepper, and serrano pepper cultivation. The results could significantly contribute to precision agriculture, sensor development, and water management.

Salt stress is a major environmental abiotic stress factor. Plants sense salt from germination onwards, negatively affecting their growth and development. Enhancing salt tolerance in crops at the sprout stage is crucial, given that it is the first stage to encounter stress. Melatonin (N-acetyl-5-methoxytryptamine) is a potent antioxidant that can alleviate stress from various environmental factors. Here, a common bean variety “Heiyundou” was used as the plant material. A concentration of 70 mMol·L⁻¹ NaCl was chosen as the stress treatment, and 100 μmol·L⁻¹ melatonin was applied. Four treatment groups were established: CK (control, water treatment), S (salt stress), M (melatonin), and M+S (salt stress with melatonin). Melatonin application under salt stress (M+S) significantly improved sprout length, surface area, volume, and average diameter compared to the salt stress group (S). Physiological analysis revealed that salt stress increased the activity of reactive oxygen species (ROS) scavenging enzymes, while exogenous melatonin (M+S) further enhanced this activity. Salt stress also significantly elevated levels of stress markers like malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and superoxide anion (O₂⁻). However, these markers decreased under the M+S treatment, indicating melatonin's protective effect. RNA sequencing (RNA-Seq) analysis identified 639 differentially expressed genes (DEGs) between the control (W) and salt stress (S) groups, and 170 DEGs between the salt stress (S) and salt stress with melatonin (M+S) groups. 40 DEGs were common to both comparisons (Co-DEGs). Gene Ontology (GO) enrichment analysis revealed that oxidoreductase activity (GO:0016491) and oxidation–reduction processes (GO:0055114) were enriched in all three groups (WvsS, SvsM+S, and Co-DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that phenylpropanoid biosynthesis (Ko00940) was the most enriched pathway in all three groups. Within this pathway, 4-coumarate-CoA ligase (4CL) and peroxidase (POD) were identified as key enzymes. Molecular docking simulations further confirmed the binding potential of melatonin to these two enzymes. Additionally, 4CL activity and lignin content analyses supported the role of phenylpropanoid biosynthesis as the underlying mechanism of melatonin's protective action. Collectively, these findings provide a theoretical basis for applying melatonin in enhancing salt tolerance in common bean crops.

Ethylene serves a pivotal function in plant growth, development, and stress responses. Initially received by receptors, ethylene signals the journey to nuclear transcription factors via downstream elements, prompting the expression of relevant genes and engaging in diverse physiological and biochemical processes. Over the preceding decades, the bulk of research efforts concentrated on unraveling the components of ethylene signaling and deciphering their molecular regulations. Remarkably less attention, however, was devoted to scrutinizing the role of ethylene signaling in fostering salt stress tolerance in plants. Crucial questions, such as whether ethylene positively or negatively impacts salt tolerance, remain insufficiently explored. Similarly, the precise role of ethylene signaling in orchestrating the SOS pathway for salt tolerance is not comprehensively understood. Hence, this article seeks to narrow this knowledge gap by exploring the latest breakthroughs in comprehending how ethylene signaling contributes to plants' responses when encountering salt stress. It will explore ethylene synthesis's role, the functions of ethylene signaling components, and the intricate molecular interplay between ethylene signaling and other pathways during salt stress responses. These studies not only deepen our comprehension of ethylene's involvement in salt stress responses but also offer valuable insights for leveraging this knowledge to develop new plant varieties resilient to salt stress.

In temperate climates, low temperatures represent a significant stressor that adversely affects crop yield and production. Tomato (Solanum lycopersicum L.) is a subtropical crop cultivated in temperate regions. However, most tomato cultivars are sensitive to chilling temperatures, which limit their cultivation in colder regions. Some microorganism-based plant biostimulants have been reported to enhance abiotic stress tolerance in crops. In this study, we isolated two Pararhizobium sp. strains (44 and 128) and tested their potential to trigger chilling stress tolerance in tomato. Through transcriptional, metabolic and biochemical analyses we demonstrate that inoculation with strains 44 and 128 enhance chilling stress tolerance by stimulating the ICE1-CBF-COR cold stress signaling pathway at transcriptional level, improving reactive oxygen species (ROS) detoxifying capacity and boosting the biosynthesis of stress-protective metabolites, such as polyamines and reduced glutathione (GSH). Treatment of tomato plants with these strains under non-stress conditions also increased tomato fruit weight and quality attributes. These findings suggest that Pararhizobium strains 44 and 128 could be valuable biostimulants for improving chilling stress tolerance and crop yield.

Plant annexins are a multigene family of phospholipid-binding, calcium-dependent proteins that respond to signals and environmental challenges as plants grow and develop. Plant annexins are functionally unique due to their ATPase/GTPase, peroxidase, and calcium (Ca²⁺) channel-regulating activities. They play a major role in controlling many different aspects of cellular and metabolic functions, plant growth and development, and reactions to both biotic and abiotic environmental stimuli. In this review, we provide an overview of how intracellular and extracellular annexins work, mechanism of reactive oxygen species (ROS) and annexins, highlight recent developments of the roles of annexins in abiotic stress tolerance in plants, and emphasize the role of annexins in plant growth and development.

The fall armyworm (FAW), Spodoptera frugiperda, poses a significant threat to maize, sorghum, and cotton crops, leading to substantial economic losses of up to 80 % in severe infestations. Despite its economic impact, the characterization of Cytochrome P450 (Cyp) genes, pivotal in regulatory metabolic processes, remains unexplored. This study identifies and investigates 33 Cyp-genes involved in critical metabolic pathways. These include fatty acid metabolism, resistance mechanisms, hormone regulation affecting moulting and developmental stages, response to phytotoxins, and detoxification of insecticides.Utilizing in-silico gene expression profiling, we pinpoint key Cyp-genes—Cyp306a1-like, Cyp9e2-like, Cyp6l1-like, Cyp12b1, and Cyp6B2-like—playing critical roles in conferring resistance against four commonly used insecticides: emamectin benzoate, tetrazolium, cyantraniliprole, and spinetoram. Our findings reveal that these identified genes are essential in detoxifying chemical treatments, thus contributing to the development of resistance in fall armyworm populations. In this investigation, key genes such as Cyp306a1-like, Cyp9e2-like, and Cyp6l1-like emerge as important regulatory genes. These genes play a role in resistance and detoxification when exposed to chemical stress. This in-silico study provides insights into the genetic mechanisms underlying resistance and regulatory genes in the fall armyworm, shedding light on potential targets for controlling the notorious agricultural pest. However, further comprehensive investigations are needed to elucidate the intricate resistance mechanisms governed by these key genes, paving the way for developing novel and effective strategies for fall armyworm management in agricultural ecosystems.