Functional Plant Biology最新文献

Viral diseases, representing the most frequent emerging infectious diseases in plants by causing significant economic losses in agricultural production. Investigating tripartite interactions among plants, pathogens and biological resistance inducers is essential for understanding plant immune system. In plant-virus interactions, resistance often depends on the fast upregulation of defense responses. Several molecular pathways and specific transcription factors (TFs) were regulated, leading to gene expression changes that result in the synthesis of effector proteins and metabolites conferring resistance against viral diseases. Upon virus detection, multiple signaling cascades are activated, ultimately causing transcriptional reprogramming in plant cells. This process is modulated by various TFs, including the WRKY family that are involved in defense mechanisms. This family has been identified across multiple plant species. In this review we examine the role of the WRKY gene family in regulating plant defense responses against viral pathogens.

Copper treatment can lead to the accumulation of reactive oxygen species, alter the cellular redox state in plants, and trigger plant adaptive mechanisms such as changes in gene expression and shifts in secondary metabolism. We investigated the effects of copper treatment on the redox state of Scutellaria baicalensis Georgi, characterized by glutathione (GSH) and oxidized glutathione (GSSG) levels. We also determined the concentrations of baicalin and baicalein, and analyzed the correlation between the redox state and these metabolites. Moreover, we analyzed the activity of glutathione reductase (GR, EC 1.6.4.2) and the expression levels of GR, phenylalanine ammonia lyase (PAL, EC 4.3.1.5) and isochorismate synthase (ICS, EC 5.4.4.2) genes. Results indicated that copper treatment increased GSH concentration at 24 and 48 h, and the ratio of GSH:GSSG, and upregulated GR expression. While the baicalin concentration showed a non-significant increase at 24 h and 72 h, baicalein exhibited a significant decrease at 48 h and 72 h. The two key genes in the salicylic acid pathway, PAL and ICS, exhibited opposite trends at 24 and 48 h after copper treatment, followed by significant decreases in both PAL and ICS at 72 h. Our results suggest that plants can mitigate the toxic effects of copper through increasing GSH biosynthesis. Baicalin and baicalein showed varying accumulation patterns in S. baicalensis subjected to different copper treatments.

Andrographis paniculata, commonly known as kalmegh is a highly valued medicinal plant. Pot-grown plants were subjected to water stress at vegetative, flowering, and fruiting stage by withholding water supply, followed by rewatering to facilitate recovery. Plants at the flowering and fruiting stage were particularly sensitive to drought stress compared to those at the vegetative stage. The plants were analysed for four diterpenoid compounds, namely andrographolide, 14-deoxyandrographolide, neoandrographolide, and andrograpanin. In plants subjected to stress at the vegetative and flowering stage, total andrographolide content increased significantly (P ≤ 0.05), by as much as 37% and 44%, respectively, over the levels in the control following 6 or more days of exposure, but remained unaffected in plants subjected to stress at the fruiting stage. Across all three stages, a significant decrease was observed in dry weight, relative water content (RWC), photosynthesis, conductance, and transpiration. Total andrographolide content was negatively correlated to dry weight, RWC, and rate of photosynthesis. These findings are useful in (1) identifying the ideal harvesting stage to achieve peak levels of bioactive compounds, (2) scheduling irrigation more efficiently to minimise yield loss due to water stress and maximise the content of bioactive compounds, and (3) developing stress-tolerant genotypes.

Chickpea (Cicer arietinum L.), a widely grown legume with significant economic importance, serves as an important nutrient source for humans. However, its production is severely constrained by Fusarium wilt, caused by the pathogen Fusarium oxysporum. Due to the high pathogenic variability, effective control remains challenging, and the plant's defense responses are not yet fully understood. In this study, we provide novel insights by identifying cultivar-specific responses and uncovering novel gene expression profiles associated with Fusarium resistance, which advance current understanding beyond previous studies. An integrative approach combining agronomic, physiological, and molecular analyses was used to evaluate chickpea cultivars under fungal stress. We assessed the disease severity index (DSI) to quantify infection levels and evaluated various morphological traits, including plant height, root length, number of pods per plant, days to maturity, 100-seed weight, and shoot biomass, to determine the physical impact of fungal stress. Antioxidant enzyme activities, including superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO), were significantly elevated, reflecting an enhanced antioxidative response to mitigate reactive oxygen species generated during pathogen attack. Biochemical parameters such as malondialdehyde (MDA), protein, and chlorophyll content were also measured, with increased MDA levels indicating increased lipid peroxidation under stress. Additionally, strong positive correlations among SOD, POD, PPO, and MDA highlight a coordinated antioxidant response that helps minimize oxidative damage. Similarly, the protein and chlorophyll contents exhibited significant correlations with enzyme activities, suggesting their roles in enhancing stress resilience. Moreover, real-time quantitative PCR analysis revealed changes in gene expression related to defense pathways, with significant upregulation of WRKY55 and MADS-Box transcription factor 23-like genes under fungal stress. This molecular response aligns with the physiological data, depicting the role of both antioxidant enzymes and gene expression in chickpea's defense mechanisms. This integrative analysis of agronomic traits, antioxidant responses, and gene expression under fungal stress conditions provides valuable insights for enhancing chickpea resilience against Fusarium wilt. Despite these findings, further research is needed to explore additional genetic factors contributing to resistance and to validate these biomarkers across diverse chickpea germplasms. Future studies should focus on applying these insights to breeding programs to develop Fusarium-resistant cultivars suitable for various agro-climatic conditions.

The terpene synthase (TPS) gene family is integral to the biosynthesis of terpenoids, which are vital for plant defence, development, and interaction with the environment. Yellowhorn (Xanthoceras sorbifolium) has gained attention for its bioactive compounds, particularly terpenoids, which have applications in pharmaceuticals, biofuels, and cosmetics. This study provides a comprehensive pan-genome-wide analysis of the TPS gene family across five yellowhorn varieties (Xg11, Xzs4, Xwf8, Xjg, and Xzg2). A total of 257 TPS genes were identified and characterised, showing diversity in their evolutionary patterns. Phylogenetic analysis revealed distinct clades corresponding to functional classes of TPS genes. Conserved domains and motifs of these genes were analysed to highlight their structural characteristics. Furthermore, expression profiling under abiotic stresses, including cold and drought, was conducted, revealing the roles of specific TPS genes in stress tolerance. Tissue-specific expression analysis demonstrated the involvement of TPS genes in key physiological processes across different plant organs. This research advances our understanding of the TPS gene family in yellowhorn, with implications for improving crop resilience and biotechnological applications.

Salinity poses a major threat to cereal crops such as sorghum. The foliar application of digitoxin at concentrations of 50, 100, and 200ppm was tested for its potential to alleviate salt stress in sorghum (Sorghum bicolor ) exposed to 200mM NaCl. Various growth parameters were analyzed, such as relative water content, malondialdehyde (MDA), osmoregulatory compunds (soluble carbohydrates and proline), ionic markers (Na+ and K+ levels in shoots and roots), and the expression of specific ion transporter genes including NHX , SOS1 , AKT1 , PPV , and PHA1 during the seedling stage. Digitoxin treatment significantly enhanced biochemical and ionic characteristics in salt-stressed plants by enhancing the membrane stability index and reducing MDA levels while boosting soluble carbohydrates, free amino acids, and proline. Real-time PCR showed that digitoxin application triggered the upregulation of genes promoting Na+ and K+ balance and reducing ion toxicity. This study underscores the potential role of digitoxin in improving salt tolerance through its influence on the regulation of ion transporter gene expression specific for K+ and Na+ ion transport and homeostasis. The effect of digitoxin on the ion transporters seems to be dose-dependent. The mechanism of digitoxin's effect on ion transporter gene expression of salt-stressed plants is discussed.

High temperature stress significantly impacts plant viability and productivity. Understanding thermotolerance mechanisms is essential for developing resilient crops. Heliotropium thermophilum , endemic to geothermal areas with extreme soil temperatures, serves as a model for studying plant high temperature stress responses. We aim to elucidate the biochemical and molecular mechanisms underlying thermotolerance in H. thermophilum . Biochemical assays quantified osmoprotectants (proline, soluble sugars, glycine-betaine, and total phenolics) and lipid peroxidation in H. thermophilum under different soil temperatures. Transcriptome analysis and quantitative Real-Time PCR were performed to validate the expression of genes involved in osmoprotectant biosynthesis, antioxidant defense, and cell wall modification. Glycine-betaine and proline levels increased by up to 189% and 104%, respectively, during peak stress. Elevated total phenolics correlated with reduced lipid peroxidation, indicating effective oxidative stress mitigation. Transcriptome analysis revealed significant upregulation of genes related to osmoprotectant biosynthesis, antioxidant defense, and cell wall modification, with notable expression of heat shock proteins and sugar transport genes. H. thermophilum employs an integrative biochemical and molecular strategy to withstand high soil temperatures, involving osmoprotectant accumulation, enhanced antioxidant defenses, and dynamic cell wall remodeling. These findings provide insights into thermotolerance mechanisms, offering potential targets for enhancing high temperature stress resilience in other crops. This study contributes to understanding plant-soil interactions and developing strategies to ensure agricultural productivity amid global climate change.

Cotton, as a globally important economic crop, has high nitrogen (N) demand but low N uptake and N utilization efficiency (NUE). Optimizing N input by improving NUE represents a critical challenge for sustainable cotton production. We applied six N levels (0, 0.04, 0.4, 1, 4, 8mM Ca(NO3 )2 , designated as N0, N0.04, N0.4, N1, N4, and N8, respectively) to examine their effects on morphology, biomass, nutrient absorption, and NUE at four treatment durations. Results showed that seedling growth and nutrient accumulation initially increased and subsequently decreased with increasing N levels. The optimal N ranges for seedling growth at 7, 14, 21 and 28d were 0.4, 0.4-1, 1-4 and 4-8mM Ca(NO3 )2 , respectively. Under optimal N, seedlings achieved maximum accumulations of N, P, K, and Ca (55.8, 8.8, 64.9, and 26.2mg/plant at 28d, respectively), while maintaining consistent N:P:K:Ca ratios of approximately 1:0.2:1.2:0.5 across seedling stage. Under low N, nutrients were preferentially allocated to roots, promoting root growth. NUE exhibited positive correlations with root traits and nutrient proportion, whereas shoot traits showed positive associations with nutrient accumulation and shoot nutrient proportion. These findings provide a theoretical basis for scientific fertilization, and establish a theoretical foundation for understanding the physiological mechanisms of efficient N use in cotton.

Chickpea is widely grown during the cooler season to avoid the adverse effects of high-temperature stress (HTS). Endogenous ascorbic acid (AsA), a prominent antioxidant, plays a crucial role in mitigating abiotic stresses in various crops. This study aimed to assess genotypic variation in AsA and to investigate the mechanisms associated with higher AsA content. The evaluation was conducted under three HTS levels (NS: >28°C, HTS-1: >33°C, HTS-2: >37°C) in field conditions during the flowering stage. AsA accumulation increased progressively with increased stress levels, showing a 27.8% increase under HTS-1 and a 61.9% increase under HTS-2 compared to NS. Notably, genotypes JG-14, IPC-06-11, ICE-15654-A, and ICCV 92944-6 exhibited significantly higher AsA content under HTS conditions. These genotypes maintained cooler canopy temperatures, higher relative water content, and increased total chlorophyll content under HTS. Additionally, these genotypes exhibited lower lipid peroxidation rates, higher proline content, and higher ascorbate peroxidase activity. Furthermore, genotypes with higher AsA levels exhibited higher seed yield and seeds per plant. Overall, the findings indicate that genotypes with higher AsA accumulation, along with the heat-tolerant check JG-14, showed superior performance in physio-biochemical processes, suggesting that AsA plays a significant role in enhancing tolerance to HTS in chickpea.

Nickel (Ni) stress severely impairs rice growth and productivity by disrupting physiological functions and inducing oxidative damage. This study investigated the individual and combined effects of nitric oxide (NO) and L -arginine (L -Arg) in mitigating Ni toxicity in rice (Oryza sativa L.). Ni exposure reduced plant biomass, chlorophyll content, photosynthesis, water use efficiency (WUE), and membrane stability, and increased Ni uptake, reactive oxygen species (ROS), malondialdehyde (MDA), electrolyte leakage (EL), and methylglyoxal (MG). Antioxidant enzyme activities and osmolyte levels were also altered. Foliar application of NO or L -Arg partially alleviated these effects, but the combined treatment (NO+L -Arg) provided superior protection. Co-treated plants showed improved growth, chlorophyll content, gas exchange, relative water content (RWC), and leaf water potential. Oxidative stress markers (H2 O2 , MDA, EL, and MG) were reduced, whereas antioxidant enzyme and glyoxalase system activities were stabilized. Soluble sugar and glycine betaine (GB) levels were optimized, and Ni accumulation in tissues was significantly decreased. Notably, the combined treatment enhanced expression of stress-related and metal detoxification genes (OsMTP1 , OsPCS5 , HSP70 , and OsZIP1 ). These findings highlight the synergistic role of NO andL -Arg in enhancing rice tolerance to Ni stress and suggest its potential as a sustainable strategy for improving crop resilience in contaminated soils.