Drought Stress Research Articles

Drought stress tolerance and metabolomics of Medicago sativa induced by Bacillus amyloliquefaciens DGL1.

This study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high-quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas. The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress. Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress. Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent.

In-vitro induced drought and heat stress on seed germination of diverse African sorghum germplasm

Abstract One of the critical growth and development stages that is vulnerable to drought and heat stress even in hardy staple crops is germination. Sorghum is a critically essential, resilient, and diverse crop that displays genotypic variations in its ability to withstand such harsh conditions, limiting crop stand and ultimately leading to yield losses. Therefore, the goal of this study was to evaluate the performance of 50 high potential genotypes of African sorghum, including landraces, breeding lines and check varieties to simulated drought and heat stress at germination stage. The study used a split plot arrangement for temperature treatments, laid in a completely randomized design with three replications. Final germination percentage, mean germination time, germination index and coefficient variation of germination time (CVt) were determined. Data was subjected to generalized linear model, principal component analysis, hierarchical agglomerative cluster analysis and principal coordinate analysis to determine statistical differences in genotypes and visualize groups of genotypes according to their overall performance in assessed germination parameters. Drought stress and supra-optimal temperatures suppressed and delayed germination. The genotypes were grouped into six distinct clusters based on their performance. Genotypes NPGRC1593, NPGRC1782, NPGRC1476 and IS224426 performed exceptionally well under both stressors and outperformed check varieties in almost all parameters assessed. To improve crop establishment and increase agricultural yields, breeding and crop improvement programs should focus on genotypes that can withstand both stresses.

Phylogenetic diversity and regionalization in the temperate arid zone

AbstractAstragalus (Fabaceae) is astoundingly diverse in temperate, cold arid regions of Earth, positioning this group as a model clade for investigating the distribution of plant diversity in the face of environmental challenges. Here, we identify the spatial distribution of diversity and endemism in Astragalus using species distribution models for 752 species and a phylogenetic tree comprising 847 species. We integrated these to map centers of species richness (SR) and relative phylogenetic diversity (RPD) and used randomization approaches to investigate centers of endemism. We also used clustering methods to identify phylogenetic regionalizations. We then assembled predictor variables of current climate conditions to test environmental factors predicting these phylogenetic diversity results, especially temperature and precipitation seasonality. We find that SR centers are distributed globally at temperate middle latitudes in arid regions, but the Mediterranean Basin is the most important center of RPD. Endemism centers also occur globally, but Iran represents a key endemic area with a concentration of both paleo‐ and neoendemism. Phylogenetic regionalization recovered an east‐west gradient in Eurasia and an amphitropical disjunction across North and South America; American phyloregions are overall most closely related to east and central Asia. SR, RPD, and lineage turnover are driven mostly by precipitation and seasonality, but endemism is driven primarily by diurnal temperature variation. Endemism and regionalization results point to western Asia and especially Iran as a biogeographic gateway between Europe and Asia. RPD and endemism highlight the importance of temperature and drought stress in determining plant diversity and endemism centers.

Genome-Wide Identification and Characterization of the PPPDE Gene Family in Rice

Protein ubiquitination is common and crucial in cellular functions, however, little is known about how deubiquitinating enzymes (DUBs) reverse regulate the ubiquitination signaling process. PPPDE family proteins are a novel class of deubiquitinating peptidases with demonstrated deubiquitination/deSUMOylating activities. In this study, we identified 10 PPPDE genes from the rice (Oryza sativa L.) genome unevenly distributed on five chromosomes, where most of these members have not been reported to date. Based on the gene structure, the OsPPPDE family consists of three distinct subgroups within the phylogenetic tree. Cis-element analysis identified light/phytohormone-responsive, development, and abiotic stress-related elements in the promoters of OsPPPDE. Furthermore, we conducted and analyzed the transcript abundance of OsPPPDE under various tissues and stresses using the transcriptome data of 352 samples from the Rice Expression Database and GEO datasets. Moreover, OsPPPDE5 showed differential regulation of its transcript abundance during Cd and drought stress. Collinearity and syntenic analysis of 101 PPPDEs and PPPDE-like proteins in 10 plant genomes indicated that this family is evolutionarily conserved. Domestication analysis suggests that OsPPPDEs may contribute to indica–japonica divergence using the data from the 3K Rice Genome Project. Our study provides a foundation for further study on the function and molecular mechanism of the OsPPPDE gene family.

Effects of Lactone- and Ketone-Brassinosteroids of the 28-Homobrassinolide Series on Barley Plants under Water Deficit.

The aim of this work was to study the ability of 28-homobrassinolide (HBL) and 28-homocastasterone (HCS) to increase the resistance of barley (Hordeum vulgare L.) plants to drought and to alter their endogenous brassinosteroid status. Germinated barley seeds were treated with 0.1 nM HBL or HCS solutions for two hours. A water deficit was created by stopping the watering of 7-day-old plants for the next two weeks. Plants responded to drought through growth inhibition, impaired water status, increased lipid peroxidation, differential effects on antioxidant enzymes, intense proline accumulation, altered expression of genes involved in metabolism, and decreased endogenous contents of hormones (28-homobrassinolide, B-ketones, and B-lactones). Pretreatment of plants with HBL reduced the inhibitory effect of drought on fresh and dry biomass accumulation and relative water content, whereas HCS partially reversed the negative effect of drought on fresh biomass accumulation, reduced the intensity of lipid peroxidation, and increased the osmotic potential. Compared with drought stress alone, pretreatment of plants with HCS or HBL followed by drought increased superoxide dismutase activity sevenfold or threefold and catalase activity (by 36%). The short-term action of HBL and HCS in subsequent drought conditions partially restored the endogenous B-ketone and B-lactone contents. Thus, the steroidal phytohormones HBL and HCS increased barley plant resistance to subsequent drought, showing some specificity of action.

Morpho-physiological studies of sandalwood-host interaction under individual and interactive water and salt stress.

To find out the possibilities of growing white sandalwood in sub-tropical regions of India where farmers facing the problem of water deficit and salinity stress, a RBD experiment was conducted. Sandalwood grown alone and with five selected hosts (Alternanthera sp., Neem, Shisham, Dek and Agarwood) on the basis of prior study under water deficit, salinity stress and combined water deficit and salinity stress. Sandalwood plants were harvested after 180days of imposing stress treatments. Morphological traits (plant height, collar diameter, shoot fresh and dry biomass) showed significant reduction under water deficit and salinity stress, which were further aggravated under combined water deficit and salinity stress. Studied plant water traits, ionic balance and gas exchange attributes were also reduced by these stresses. While among studied host, Shisham and Dek identified as the best host species under water deficit, salinity and interactive stress by maintaining ion homeostasis, osmotic adjustments and plant water regulation. Results depicted that sandalwood plants cultivated alone were not able to survive under salinity and combined stress conditions and showed poor growth under water deficit and control conditions. Different indices were also calculated based on morpho-physiological and ionic traits and also indicated that sandalwood grown with Dalbergia sissoo and Melia dubia showed higher drought, salt and stress tolerance potential, which made sandalwood adaptable under these stresses. Therefore, the present study signifies the importance of host especially D. sissoo and M. dubia which might be excellent long-term host species for sandalwood cultivation under sub-tropical conditions to thrive under changing environments.

Introgression of Δ1-pyrroline-5-carboxylate synthetase (PgP5CS) confers enhanced resistance to abiotic stresses in transgenic tobacco.

Δ1-pyrroline-5-carboxylate synthetase (P5CS) is one of the key regulatory enzymes involved in the proline biosynthetic pathway. Proline acts as an osmoprotectant, molecular chaperone, antioxidant, and regulator of redox homeostasis. The accumulation of proline during stress is believed to confer tolerance in plants. In this study, we cloned the complete CDS of the P5CS from pearl millet (Pennisetum glaucum (L.) R.Br. and transformed into tobacco. Three transgenic tobacco plants with single-copy insertion were analyzed for drought and heat stress tolerance. No difference was observed between transgenic and wild-type (WT) plants when both were grown in normal conditions. However, under heat and drought, transgenic plants have been found to have higher chlorophyll, relative water, and proline content, and lower malondialdehyde (MDA) levels than WT plants. The photosynthetic parameters (stomatal conductance, intracellular CO2 concentration, and transpiration rate) were also observed to be high in transgenic plants under abiotic stress conditions. qRT-PCR analysis revealed that the expression of the transgene in drought and heat conditions was 2-10 and 2-7.5 fold higher than in normal conditions, respectively. Surprisingly, only P5CS was increased under heat stress conditions, indicating the possibility of feedback inhibition. Our results demonstrate the positive role of PgP5CS in enhancing abiotic stress tolerance in tobacco, suggesting its possible use to increase abiotic stress-tolerance in crops for sustained yield under adverse climatic conditions.

Heterologous expression of the maize transcription factor ZmbHLH36 enhances abiotic stress tolerance in Arabidopsis

AbstractBasic helix-loop-helix (bHLH) transcription factors are widely distributed in eukaryotes, and in plants, they regulate many biological processes, such as cell differentiation, development, metabolism, and stress responses. Few studies have focused on the roles of bHLH transcription factors in regulating growth, development, and stress responses in maize (Zea mays), even though such information would greatly benefit maize breeding programs. In this study, we cloned the maize transcription factor gene ZmbHLH36 (Gene ID: 100193615, GRMZM2G008691). ZmbHLH36 possesses conserved domains characteristic of the bHLH family. RT-qPCR analysis revealed that ZmbHLH36 was expressed at the highest level in maize roots and exhibited different expression patterns under various abiotic stress conditions. Transgenic Arabidopsis (Arabidopsis thaliana) plants heterologously expressing ZmbHLH36 had significantly longer roots than the corresponding non-transgenic plants under 0.1 and 0.15 mol L−1 NaCl treatment as well as 0.2 mol L−1 mannitol treatment. Phenotypic analysis of soil-grown plants under stress showed that transgenic Arabidopsis plants harboring ZmbHLH36 exhibited significantly enhanced drought tolerance and salt tolerance compared to the corresponding non-transgenic plants. Malondialdehyde contents were lower and peroxidase activity was higher in ZmbHLH36-expressing Arabidopsis plants than in the corresponding non-transgenic plants. ZmbHLH36 localized to the nucleus when expressed in maize protoplasts. This study provides a systematic analysis of the effects of ZmbHLH36 on root growth, development, and stress responses in transgenic Arabidopsis, laying a foundation for further analysis of its roles and molecular mechanisms in maize.

Comprehensive identification of maize ZmE2F transcription factors and the positive role of ZmE2F6 in response to drought stress

BackgroundThe early 2 factor (E2F) family is characterized as a kind of transcription factor that plays an important role in cell division, DNA damage repair, and cell size regulation. However, its stress response has not been well revealed.ResultsIn this study, ZmE2F members were comprehensively identified in the maize genome, and 21 ZmE2F genes were identified, including eight E2F subclade members, seven DEL subfamily genes, and six DP genes. All ZmE2F proteins possessed the DNA-binding domain (DBD) characterized by conserved motif 1 with the RRIYD sequence. The ZmE2F genes were unevenly distributed on eight maize chromosomes, showed diversity in gene structure, expanded by gene duplication, and contained abundant stress-responsive elements in their promoter regions. Subsequently, the ZmE2F6 gene was cloned and functionally verified in drought response. The results showed that the ZmE2F6 protein interacted with ZmPP2C26, localized in the nucleus, and responded to drought treatment. The overexpression of ZmE2F6 enhanced drought tolerance in transgenic Arabidopsis with longer root length, higher survival rate, and biomass by upregulating stress-related gene transcription.ConclusionsThis study provides novel insights into a greater understanding and functional study of the E2F family in the stress response.

Characterization of ZmSnRK1 genes and their response to aphid feeding, drought and cold stress

AbstractThe SnRK1 complex in plants regulates metabolism in response to environmental stresses and glucose depletion, for stress adaptation and energy homeostasis. Through phosphorylation of various targets, SnRK1 orchestrates intricate regulatory mechanisms involved in autophagy, nutrient remobilization, and TOR activity inhibition, showcasing its pivotal role in coordinating plant metabolism and stress responses. The present study aimed to identify members of the SnRK1 gene family in the maize genome and characterize them using bioinformatics and expression analyses under aphid feeding, drought, and cold stress. The focus of the study was to conduct a comprehensive analysis towards determining gene diversity of ZmSnRK1 genes, constructing intricate 3D structures, and identifying stress-related cis-elements. Four SnRK1 genes were identified, which were named ZmSnRK1.1, ZmSnRK1.2, ZmSnRK1.3, and ZmSnRK1.4. The SnRK1 proteins were found to have a distribution of conserved motifs; however, the distinction between monocots and dicots in the phylogenetic tree was clearly demonstrated. Analysis of the promoter region revealed that the ZmSnRK1 genes contain stress-related cis-elements. Compared to the control, ZmSnRK1.3 significantly upregulated in response to aphid feeding and cold stress, while ZmSnRK1.2 showed elevated expression under drought conditions. The expression of the other two genes under these treatments was generally unperturbed. The findings of this study are poised to establish a valuable scientific foundation for future research on the roles of the SnRK1 gene family in plants, providing valuable insights for enhancing genetic resilience to stress and optimizing yield traits.

Screening of Wheat Genotypes for Water Stress Tolerance Using Soil–Water Relationships and Multivariate Statistical Approaches

Drought stress constricts crop production around the world. Employing high-yielding cultivars with drought tolerance might be the ideal professional approach to coping with its detrimental outcomes. As a result, the current study was performed to investigate the sensitivity and tolerance of nine wheat genotypes to drought stress. In a randomized block design experiment, nine wheat genotypes were subjected to four water treatments: 100%, 85%, 70%, and 55% of the available water (AW). Four water regimes in two growing seasons were counted as eight environmental zones. The leaf’s water relations and photosynthetic pigment were estimated, as well as growth and yield parameters. Univariate and multivariate statistical approaches, including the new method of multi-trait genotype–ideotype distance (MGIDI), were used for evaluation. The analysis of variance revealed that genotype, environment, and their interactions had a highly significant effect on all traits. The same trend was shown by the additive main effects and multiplicative interaction (AMMI) analysis of variance for grain yield across the environments. The AMMI biplot study indicated that the G8 genotype is the most stable in terms of water stress. The G7 genotype can withstand droughts up to 55% of the available water, while the G8 and G3 genotypes can withstand droughts up to 70% of the available water. Based on all examined traits, this index was used to identify the stable genotypes G7, G8, and G3, which can therefore be suggested for cultivation during drought conditions. Furthermore, we found a positive correlation between the MGIDI, ANOVA, and tolerance index results, indicating that the same desirable genotypes of G7 and G8 were identified by these procedures as being highly tolerant and stable across a range of soil moisture conditions. Based on MGIDI analysis, we can recommend that the G7 genotype exhibits higher grain yield and yield-related traits with the best drought-tolerant indices.

The Effects of Long-Term Precipitation Exclusion on Leaf Photosynthetic Traits, Stomatal Conductance, and Water Use Efficiency in Phyllostachys edulis

Ongoing climate change is projected to intensify drought stress globally. Understanding the response mechanisms of Phyllostachys edulis (Carrière) J. Houz. (moso bamboo) to long-term drought is crucial, given its significance as a carbon sequestration resource. In this study, precipitation exclusion was implemented to simulate drought stress and we investigated the effects of long-term drought on the photosynthetic parameters, stomatal conductance, and water use efficiency of moso bamboo. The results showed that throughout all growth seasons, the maximum net photosynthetic rates (Pmax) of bamboo at all ages under long-term drought conditions (after 8 years of precipitation exclusion treatment) were significantly lower than those of the control (p < 0.05). It can be concluded that long-term drought reduced the maximum photosynthetic capacity of the bamboo at all ages. Under long-term drought conditions, there were many seasons where the light saturation point (LSP) of first-degree (1–2 years old) bamboo and third-degree (5–6 years old) bamboo under drought was significantly lower than those of the control, while the LSP value of second-degree (3–4 years old) bamboo under drought was significantly higher than that of the control. This suggests that long-term drought reduced the ability of first-degree and third-degree bamboo to utilize strong light, while improving the ability of second-degree bamboo to utilize strong light in summer, autumn, and winter. Under long-term drought conditions, the light compensation point (LCP) and the apparent quantum efficiency (AQY) of the bamboo decreased. It can be concluded that long-term drought reduced the ability of first-degree bamboo to utilize weak light in all seasons, as well as the ability of second-degree bamboo to utilize weak light in spring and autumn; meanwhile, it improved the ability of second-degree bamboo to utilize weak light in summer and winter, and the ability of third-degree bamboo to utilize weak light in spring, summer, and autumn. In the high light range (PARi > 1000 µmol · m−2 · s−1), there were significant differences in stomatal conductance (gs) among different the different treatments of bamboo, which were influenced by both the growing season and the forest age. Compared to the control, under drought conditions, the stomatal conductance of third-degree bamboo increased in spring and that of the second-degree bamboo increased in autumn. The correlation analysis showed that the relationship between the stomatal conductance and vapor pressure deficit (VPDL) of bamboo under long-term drought conditions showed a significant polynomial relationship in both high and low light ranges. The correlation between the instantaneous water use efficiency (iWUE) and VPDL for the drought and control treatments of bamboo also showed a significant polynomial relationship in high light ranges. It was found that long-term drought changed the photosynthetic parameters of the bamboo, reflecting its ability to tolerate and adapt to drought in different seasons. Age-related differences in photosynthetic parameters should be fully considered in forest age structure adjustments and forest thinning procedures to strengthen the light intensity and maintain the opening of the stoma. These results provide a theoretical basis for the efficient and sustainable cultivation of bamboo under global climate change.

Evaluation of Sunflower Hybrids Variability in Response to Drought Stress: Implications for Oil and Protein Content Optimization

Oilseed crops are third most important for human being after cereals and sugars. Sunflower is a vital oilseed crop, which is grown globally for its oil purposes. Sunflower seeds are also the most important protein source. Sunflower contains two primary protein types: water-soluble albumins and salt-soluble globulins. The genotype plays a crucial role in determining the fatty acid composition of oil. However, environmental factors like water availability and temperature fluctuations during the grain-filling stage can also significantly impact on oil content. That’s why this study was aimed to investigate the impact of water deficit environments on seed yield and related traits of sunflower hybrids. In this study seven sunflower hybrids (SF-177, Pl-64 A 93, Hysun-33, Hysun-39, US-666, FSS-64 and Agsun-5264) were sown according to RCBD by using three replications. Data was recorded days taken to initiation of flowering, plant height, 1000 seed weight, oil content and protein content. Results showed that drought stress adversely affected all the parameters in this experiment, but some hybrids perform better for yield and oil content under drought conditions. Such as hybrid SF-177 and Hysun-39 represented least difference in 1000 achenes weight under normal and drought conditions. Hybrid FSS-64 (44.33%) and Hysun-33 (43.66%) showed highest oil content under drought conditions. While hybrid Agsun-5264 and Hysun-39 showed maximum protein content under drought stress.

Identification and validation of stable reference genes for RT-qPCR analyses of Kobresia littledalei seedlings

BackgroundKobreisa littledalei, belonging to the Cyperaceae family is the first Kobresia species with a reference genome and the most dominant species in Qinghai-Tibet Plateau alpine meadows. It has several resistance genes which could be used to breed improved crop varieties. Reverse Transcription Quantitative Real-Time Polymerase Chain Reaction (RT-qPCR) is a popular and accurate gene expression analysis method. Its reliability depends on the expression levels of reference genes, which vary by species, tissues and environments. However, K.littledalei lacks a stable and normalized reference gene for RT-qPCR analysis.ResultsThe stability of 13 potential reference genes was tested and the stable reference genes were selected for RT-qPCR normalization for the expression analysis in the different tissues of K. littledalei under two abiotic stresses (salt and drought) and two hormonal treatments (abscisic acid (ABA) and gibberellin (GA)). Five algorithms were used to assess the stability of putative reference genes. The results showed a variation amongst the methods, and the same reference genes showed tissue expression differences under the same conditions. The stability of combining two reference genes was better than a single one. The expression levels of ACTIN were stable in leaves and stems under normal conditions, in leaves under drought stress and in roots under ABA treatment. The expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression was stable in the roots under the control conditions and salt stress and in stems exposed to drought stress. Expression levels of superoxide dismutase (SOD) were stable in stems of ABA-treated plants and in the roots under drought stress. Moreover, RPL6 expression was stable in the leaves and stems under salt stress and in the stems of the GA-treated plants. EF1-alpha expression was stable in leaves under ABA and GA treatments. The expression levels of 28 S were stable in the roots under GA treatment. In general, ACTIN and GAPDH could be employed as housekeeping genes for K. littledalei under different treatments.ConclusionThis study identified the best RT-qPCR reference genes for different K. littledalei tissues under five experimental conditions. ACTIN and GAPDH genes can be employed as the ideal housekeeping genes for expression analysis under different conditions. This is the first study to investigate the stable reference genes for normalized gene expression analysis of K. littledalei under different conditions. The results could aid molecular biology and gene function research on Kobresia and other related species.

Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System

Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System

Nutrition addition alleviates negative drought effects on Quercus acutissima seedlings

Changing precipitation patterns have exacerbated severe drought events, causing tree die-off and forest mortality. Nutrition addition, as a critical method for forest management, may alleviate negative drought effects. Therefore, we set up a two-factor orthogonal experiment to study the responses of the leaf structural traits of Quercus acutissima to nutrition addition under drought stress. Leaf structural traits, including leaf morphological traits, leaf mass, and leaf nutrition traits, were measured under nine water and nutrition addition treatments. Two-way analysis of variance was used to detect the main effect and interaction of water and nutrition addition on leaf structural traits, principal component analysis was used to screen key traits. Our results show that drought had a unique and decisive effect on leaf length, leaf width, and leaf center, while leaf thickness only depended on nutrition addition. Conversely, no treatments changed the leaf length-width ratio and leaf nitrogen-phosphorus ratio. Besides, nutrition addition alleviated negative drought effects on leaf area, leaf saturated mass, leaf dry mass, leaf nitrogen content, leaf phosphorus content, leaf volume, specific leaf area, and leaf dry-matter content. According to the principal component 1 (54.83%), we screened seven key traits from leaf structural traits, including leaf area, leaf saturated mass, leaf dry mass, leaf nitrogen content, leaf volume, specific leaf area, and leaf dry-matter content, to effectively capture changes in leaf structural traits. Our results demonstrate that under drought stress, nutrition addition enhanced soil nutrition availability, increased leaf nitrogen and leaf phosphorus content, and finally alleviated negative drought effects. Thus, nutrition addition is crucial for plants to get through drought and for forest ecological restoration under global climate change.

Nitric Oxide Promotes Adventitious Rooting in Cucumber Under Drought Stress Through Regulating Ascorbate Glutathione Cycle and Protein S-Nitrosylation

Nitric Oxide Promotes Adventitious Rooting in Cucumber Under Drought Stress Through Regulating Ascorbate Glutathione Cycle and Protein S-Nitrosylation

Isolation of Proline -rich protein Gene from Potato under Drought Stress

Isolation of Proline -rich protein Gene from Potato under Drought Stress

Old Pinus massoniana forests benefit more from recent rapid warming in humid subtropical areas of central-southern China

Trees progress through various growth stages, each marked by specific responses and adaptation strategies to environmental conditions. Despite the importance of age-related growth responses on overall forest health and management policies, limited knowledge exists regarding age-related effects on dendroclimatic relationships in key subtropical tree species. In this study, we employed a dendrochronological method to examine the impact of rapid warming on growth dynamics and climatic sensitivity of young (40–60 years) and old (100–180 years) Pinus massoniana forests across six sites in central-southern China. The normalized log basal area increment of trees in both age groups increased significantly following rapid warming in 1984. Trees in young forests further showed a distinct growth decline during a prolonged severe drought (2004–2013), whereas those in old forests maintained growth increases. Tree growth was more strongly influenced by temperature than by moisture, particularly in old forests. Spring temperatures strongly and positively impacted the growth of old trees but had a weaker effect on young ones. Old forests had a significantly lower resistance to extreme drought but faster recovery compared to young forests. The “divergence problem” was more pronounced in younger forests due to their heightened sensitivity to warming-induced drought and heat stress. With ongoing warming, young forests also may initially experience a growth decline due to their heightened sensitivity to winter drought. Our findings underscore the importance of considering age-dependent changes in forest/tree growth response to warming in subtropical forest management, particularly in the context of achieving “Carbon Peak & Carbon Neutrality” goals in China.

The effect of foliar application of plant growth regulators on functional and qualitative characteristics of wheat (Triticum aestivum L.) under salinity and drought stress conditions

This study aimed to investigate the effect of salinity and water stress on the physiological and functional characteristics of winter wheat (Triticum aestivum L.) under the foliar application of plant growth regulators (PGRs). The experiment was carried out as a split plot based on a randomized complete block design with three replications in two environments. In each environment, water stress at two irrigation levels (after 90 and 120 mm of pan evaporation) and with two EC of 1.5 and 10 dS/m in the main plots and spraying of PGRs including salicylic acid (SA), gibberellic acid (GA3), and cytokinins (CK) (purine) content with a concentration of 100 ppm and the control treatment (spraying solution with normal water) were placed in subplots. Results indicated that all treatments caused significant increases in functional and qualitative characteristics and yield of Triticum aestivum L. The saline environment and irrigation level after 120 mm of pan evaporation caused a reduction in grain yield in all traits except for seed proline, seed nitrogen content, and seed protein content. Also, the combined foliar application of GA3 + CK + SA increased yield in most traits. The highest RWC of flag leaves was observed in the foliar application of GA3 + SA (3.36 kg/ha) and then in the foliar application of GA3 + SA + CK (57.87 kg/ha). GA3 interacts with PGR spraying to balance another development under saline and non-saline conditions.