Functional Plant Biology最新文献

Water use efficiency (WUE) is a key index to predict the impact of climate change on ecosystem carbon and water cycles, the tradeoff of stem and leaf traits determined the WUE and resource competitiveness of individual plants. Four altitudinal gradients of 3400 m, 3500 m, 3600 m, and 3700 m were selected as experimental sites in Gahai Wetland on the Ruoerge Plateau.Additionally, the Mantel Test method and the standardized major axis estimation (SMA) method were employed to examine the relationship between stem-leaf tradeoff and WUE of Kobresia tibetica in alpine peat swamps at different elevations was studied. The results showed that:with the increase of altitude, the surface water area decreased gradually, and the height and fractional vegetation cover of wetland community, Stomatal conductance (Gs) and Transpiration rate (Tr) of Kobresia tibetica showed a decreasing trend (P<0.05), Water use efficiency (WUE), Photosynthetically Active Radiation (PAR), Vapor Pressure Deficit (VPD), and the height, fractional vegetation cover and root-shoot ratio of Kobresia tibetica showed an increasing trend (P <0.05).The leaf area (LA), leaf thickness (LT), specific leaf area (SLA), stem length (SL) and WUE of Kobresia Tibetica showed different correlations at different places. With the increase of altitude, the tradeoff between stems and leaves of Kobresia tibetica changed from stems to leaves, the tradeoff between leaf area and leaf thickness changes from favoring leaf area to leaf thickness, stem and leaf configuration changed from long stem-large leaf area to short stem-small leaf area, the net photosynthetic rate(Pn) and WUE increased, and the structural cost and photosynthetic efficiency return of Kobresia tibetica leaves changed from "high-input-slow return" to "low-input-fast return". It reflects the ecological strategy of synergistic adaptation between stem and leaf morphology and photosynthetic characteristics of plants in alpine peat swamp in heterogeneous habitat.

One of the main melatonin metabolites in plants is cyclic 3-hydroxymelatonin (3-OHM), although its potential functions in plant life remain unclear. To understand the importance of 3-OHM in plants in terms of stress tolerance, we investigated whether tolerance to chilling stress could be increased during germination and emergence using exogenous 3-OHM applications in pepper. After being exposed to varying concentrations of 3-OHM for 24 h, pepper seeds were tested for germination and emergence under both optimum and chilling stress conditions. Applying 3-OHM prior to sowing had a positive effect on pepper seed germination and seedling emergence performance under chilling stress circumstances. Concentrations of 10 and 50 μM 3-OHM were determined to be the most effective 3-OHM concentrations, therefore the germination and emergence percentages and rates increased in contrast to control treatments. 3-OHM treatments raised the activity of the enzymes peroxidase, catalase and superoxide dismutase while decreasing the quantities of reactive chemicals such as hydrogen peroxide and thiobarbituric acid in seedlings. Furthermore, treatments had a positive effect on seedling proline content, root length, vigor index and chlorophyl content. In conclusion, increased antioxidant enzyme levels significantly reduce lipid peroxidation in tissues, consequently boosting pepper seed germination and seedling emergence performance.

Alkaline stress severely impairs the growth and yield of Zea mays L. by disrupting physiological and biochemical functions. This study evaluated green-synthesized ZnO and MgO nanoparticles (NPs), prepared using neem and licorice extracts, for mitigating alkaline stress. NPs were nanosized, crystalline, and functionalized by phytochemicals, confirmed by scanning electron microscopy, FT-IR spectroscopy, UV-vis spectroscopy, and energy dispersive X-ray spectroscopy. A pot experiment using NPs (25-200 ppm) under control and alkaline stress assessed morphological, physiological, biochemical, and ionic responses. Alkaline stress reduced root fresh and dry weight to 2.60 and 0.66 g (-59.6%, -31.0%), shoot fresh and dry weight to 2.60 and 0.38 g (-59.6%, -70.0%), and chlorophyll a, b, and carotenoids to 1.31, 0.67, and 2.40 mg g-1 (-62.4%, -54.7%, -62.8%), whereas it increased malondialdehyde (MDA) (244.6%), H₂O₂ (457.7%), and relative membrane permeability (RMP) (55.9%). The combined ZnO (50 ppm) and MgO (50 ppm) treatment improved chlorophyll a, b, and carotenoids to 3.48, 1.48, and 6.45 mg g-1 (165.4%, 120.3%, 168.5%), and total soluble protein (392.8%), total protein (301.0%), proline (105.5%), glutathione (35.6%), and ascorbic acid (44.2%). Antioxidant enzymes increased, with superoxide dismutase at 29.52 U mg-1 (452.8%), peroxidase at 24.44 U mg-1 (862%), and ascorbate peroxidase at 51.62 U mg-1 (560%), whereas MDA, H2O2, and RMP (-78.1%) were reduced. High NP concentrations (ZnO 100 ppm + MgO 100 ppm) were toxic. Moderate ZnO and MgO NP doses enhanced resilience, yield stability, and sustainable agriculture.

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.