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Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This document is an editorial from the journal Frontiers in Plant Science titled "The role of lipids in abiotic stress responses." It discusses the importance of lipids in plant responses to environmental stress, such as drought and high temperatures. The editorial highlights the complex relationship between lipids and stress adaptation in plants and emphasizes the need for further research in lipidomics and lipid signaling pathways. The document also mentions specific research papers included in the journal issue, which explore topics such as lipid remodeling in maize hybrids under drought, lipid modulation in peanuts under heat stress, the effect of temperature on lipid accumulation in microalgae, and the identification and expression analysis of KCS genes in soybean in response to abiotic stress. Overall, understanding the role of lipids in stress response is crucial for developing resilient and stress-tolerant crops. [Extracted from the article]

Climate change is raising concerns about how forests will respond to extreme droughts, heat waves and their co-occurrence. In this greenhouse study, we tested how carbon and water relations relate to seedling growth and mortality of northeastern US trees during and after extreme drought, warming, and combined drought and warming. We compared the response of our focal species red spruce (Picea rubens Sarg.) with a common associate (paper birch, Betula papyrifera Marsh.) and a species expected to increase abundance in this region with climate change (northern red oak, Quercus rubra L.). We tracked growth and mortality, photosynthesis and water use of 216 seedlings of these species through a treatment and a recovery year. Each red spruce seedling was planted in containers either alone or with another seedling to simulate potential competition, and the seedlings were exposed to combinations of drought (irrigated, 15-d 'short' or 30-d 'long') and temperature (ambient or 16 days at +3.5 °C daily maximum) treatments. We found dominant effects of the drought reducing photosynthesis, midday water potential, and growth of spruce and birch, but that oak showed considerable resistance to drought stress. The effects of planting seedlings together were moderate and likely due to competition for limited water. Despite high temperatures reducing photosynthesis for all species, the warming imposed in this study minorly impacted growth only for oak in the recovery year. Overall, we found that the diverse water-use strategies employed by the species in our study related to their growth and recovery following drought stress. This study provides physiological evidence to support the prediction that native species to this region like red spruce and paper birch are susceptible to future climate extremes that may favor other species like northern red oak, leading to potential impacts on tree community dynamics under climate change. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] Scutellaria baicalensis Georgi (SBG) is a Chinese medicine. This paper studies the combined effect of initial soil water content and progressive drought on physiological traits and quality of SBG. [Method] The pot experiment was conducted in a mobile water shelter. The initial soil water content in the pots were controlled at 40%, 60% and 80% of the field capacity (FC) to represent severe, moderate, and mild drought, respectively. In each treatment, we measured the biomass, photosynthetic characteristics, osmotic substances, activities of antioxidant enzymes and active ingredients of the plants. [Result] ① No significant difference in biomass accumulation was found between the treatments. ② During the stress period, baicalin content was significantly higher in the 80%FC treatment, baicalein content was significantly higher in the 40%FC treatment and the baicalin content decreased with initial soil water treatment in the order of 40%FC>60%FC>80%FC. When the soil water content was 40%FC and 60%FC, the baicalin content was 17.3% and 11.3% higher than that when soil water content was 80%FC. Change in soil water contents did not have a significant impact on baicalein content. ③ Net photosynthetic rate, transpiration rate, stomatal conductance and intercellular carbon dioxide concentration all decreased as the plants grew, regardless of the soil water treatments. 8-10 d after the onset of water stress, the net photosynthetic rate did not show significant differences between the 60%FC and 80%FC treatments. ④ Under water stress, the content of malondialdehyde and proline in all treatments increased as the plants grew. The proline content was the highest in the 80%FC treatment, reaching 121.66 µg/g. ⑤ The activities of POD and CAT responded to water stress similarly, both increasing gradually as water stress persisted. The impact of soil water on activity of SOD was ranked in the order of 40%FC>60%FC>80%FC. ⑥ The active ingredients were higher in the 40%FC and 60%FC treatments. [Conclusion] Severe progressive drought with the soil water content kept at 40%FC reduced photosynthesis and increased baicalein content, osmolytes and activity of antioxidant enzymes. Mild and severe droughts by keeping the soil water content at 40%FC and 60%FC can improve accumulation of active ingredients in SBG. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Anhui Agricultural Sciences is the property of Journal of Anhui Agricultural Sciences Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drought stress is one of the most important abiotic stresses which causes many yield losses every year. This paper presents a comprehensive review of recent advances in international drought research. First, the main types of drought stress and the commonly used drought stress methods in the current experiment were introduced, and the advantages and disadvantages of each method were evaluated. Second, the response of plants to drought stress was reviewed from the aspects of morphology, physiology, biochemistry and molecular progression. Then, the potential methods to improve drought resistance and recent emerging technologies were introduced. Finally, the current research dilemma and future development direction were summarized. In summary, this review provides insights into drought stress research from different perspectives and provides a theoretical reference for scholars engaged in and about to engage in drought research. [ABSTRACT FROM AUTHOR]

[Objective] Crops often suffer from interval drought and rehydration (rainfall or irrigation) during the whole growth period, especially in arid and semi-arid areas. Under drought stress, the growth and development of crops are inhibited, and the yield is reduced; meanwhile, the plants drought tolerance will be induced. In order to compensate loss of yield or growth induced by drought stress, crop often shows compensatory after rehydration, which produces compensation or even over compensation effect on yield. The compensation effect of post drought is the result of crop's positive response to drought stress and compensatory growth after rehydration. It can effectively improve crop yield and water use efficiency in crop production in arid areas. [Methods] Source sink relationship is widely used to explain the crop yield formation, and regulating the source sink relationship is one of key way to improve crop yield. The compensation effect of post drought is highly related to the source sink response of crops. Based on the current research progress, this paper tries to explain the compensation effect of post drought in source and ink way. [Results] Under the drought stress, in the source, the stomata were closed, photosynthesis was decreased and soluble carbohydrate accumulation was increased, while sink activity was often increased. After rehydration, the metabolism of soluble carbohydrate in the source (leaf) was enhanced, which enhanced the photosynthesis and the ability of carbohydrate synthesis; meanwhile, the sink activity (grain) was maintained at a high level, and the rate of assimilate unloading and accumulation was accelerated; the assimilate in the flow remained at a high level. During this process, the activities of sucrose invertase (INV), ell wall invertase (CW-INV) and fructan exohydrolases (1-FEH w3) play important roles in the source sink response to the compensation effect of post-drought. [Conclusion] This paper integrated the mechanism of compensation effect of post drought in the perspective of source sink relationship, which provides a theoretical basis for understanding the mechanism of compensation effect of post drought and improving crop water efficient in arid areas. [ABSTRACT FROM AUTHOR]

Copyright of Feed Research is the property of Editorial Board of Feed Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shanxi Agricultural Sciences is the property of Shanxi Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Wheat (Triticum aestivum L.) is one of the most widely grown and vital cereal crops, containing a high percentage of basic nutrients such as carbohydrates and proteins. Drought stress is one of the most significant limitations on wheat productivity. Due to climate change influences plant development and growth, physiological processes, grain quality, and yield. Drought stress has elicited a wide range of plant responses, namely physiological and molecular adaptations. Biopriming is one of the recent attempts to combat drought stress. Mitigating the harmful impact of abiotic stresses on crops by deploying extreme-habitat-adapted symbiotic microbes. The purpose of this study was to see how biopriming Triticum aestivum grains affected the effects of inoculating endophytic fungi Aspergillus fumigatus ON307213 isolated from stressed wheat plants in four model agricultural plants (Gemmiza-7, Sids-1, Sakha8, and Giza 168). And its viability in reducing drought stress through the use of phenotypic parameters such as root and shoot fresh and dry weight, shoot and root length, and so on. On a biochemical and physiological level, enzymatic parameters such as catalase and superoxidase dismutase are used. Total phenolics, flavonoids, and photosynthetic pigments are non-enzymatic parameters. Making use of molecular techniques such as reverse transcriptase polymerase chain reaction (RT-PCR). Results: It has been found that using Aspergillus fumigatus as a biological biopriming tool can positively impact wheat plants experiencing drought stress. The total biomass of stressed wheat plants that had been bio-primed rose by more than 40% as compared to wheat plants that had not been bio-primed. A. fumigatus biopriming either increased or decreased the amount of enzymatic and non-enzymatic substances on biochemical scales, aside from the noticeable increase in photosynthetic pigment that occurs in plants that have been bio-primed and stressed. Drought-resistant genes show a biopriming influence in gene expression. Conclusions: This is the first paper to describe the practicality of a. fumigatus biopriming and its effect on minimizing the degrading effects of drought through water limitation. It suggests the potential applications of arid habitat-adapted endophytes in agricultural systems. [ABSTRACT FROM AUTHOR]

【Objective】 Drought is an abiotic stress affecting crop growth the most in central and northern China. Tremendous research has been conducted over the past decades to understand the response of plants to drought and develop mitigation methods to ameliorate its detrimental effect. In this paper, we analyze the research processes, research hotspots, perspectives on advancing drought management practices in China. 【Method】 The analysis is based on papers published from 2018 to 2022. We used the Citespace and VOSviewer software to analyze the papers indexed by China National Knowledge Infrastructure (CNKI) and Web of Science (WOS). Our analysis focused on research that investigated the impact of drought on plant growth, physiological processes, and gene expression. The keywords used for search in CNKI were ‘salt tolerance’, ‘seedling stage’, and ‘drought resistance identification’, while those used for research in WOS were ‘ascorbate peroxidase’, ‘water use’, and ‘ectopic expression’. 【Result】 Researches on the effect of drought on plants in China over the last five years predominantly focused on four areas: impact of drought stress on morphology and anatomy of leaves, effects of drought stress on photosynthetic characteristics of plants, effects of drought stress on osmotic regulation substances and antioxidant enzymes in plants, effects of drought stress on genetic expression in plants. Current research in this area is the identification and transfer of drought-resistance genes to plants which are prone to drought or drought-salt stress. The two research hotspots are application of nanomaterials to alleviate the impact of drought stress on plants, and applying multi-omics joint analysis (genomics, transcriptomics, proteomics, metabolomics) and advanced technologies such as transgenic techniques, gene editing, gene silencing to enhance the resistance of plants to drought. 【Conclusion】 Research on the impact of drought on plants in China over the past five years is diverse, ranging from developing techniques to ameliorate its detrimental influence to understanding the molecular mechanisms underlying the response of plants to drought stress.

[Objective) The present paper aimed to obtain the complete sequence of SsREMO-la gene, conduct tissue-specific expression, qPCR expression analysis, sub-cellular localization study, and the phenotypic changes of Arabidopsis thaliana with SsREMO-la gene transfer and the expression pattern of CAT-1 gene. (Method) The complete sequence of SsREMO-la gene was obtained by PCR, purification, cloning and sequencing from Hainan sugarcane wild species (Sp-24). Drought stress was applied to the normal growth of the seedlings. Young leaves, roots and stems at 0, 1, 2, 3, 4 and 5 days after the stress treatment were collected for tissue-specific expression analysis and qPCR analysis. The tissue location and function of SsREMO-1a were analyzed by tobacco sub-cellular mapping and gene transformation techniques. PB1221-SSREMO-1a-GFP fusion expression vector was constructed and transformed into tobacco for cell localization analysis. The over-ex- pression vector pCAMBIA 1304-SsREMO-la was constructed, and SsREMO-1a was introduced into A. thaliana by agrobacterium transformation. The phenotypes of plants at 0, 1, 2, 3, 4 and 5 days after drought stress and the expression of CAT-1 gene were observed. [Result] The full length of SsREMO-1a gene was 738 bp, and the open code frame (ORF) was 564 bp, encoding 187 amino acids. Tissue-specific expression showed that SsREMO-1a was expressed in roots, stems and leaves. qPCR results showed that the gene was induced by drought stress and showed significantly up-regulated expression. The results of sub-cellular localization showed that SsREMO-1a protein was localized on the cell membrane. A total of 11 transgenic A. thaliana lines were obtained, and the drought resistance identification showed that the transgenic plants could improve the drought resistance of the plants. The expression of CAT-1 gene in transgenic plants was significantly in- creased. [Conclusion] SsREMO-1a can improve the drought resistance of plants and regulate CAT-1 gene to some extent. [ABSTRACT FROM AUTHOR]

【Objective】The paper aims to explore the effect of drought stress on endogenous hormones in Camellia reticulata and the molecular mechanism of plant hormone signal transduction pathway responding to drought stress.【Method】The pot seedlings of half-one-year-old wild C.reticulata were used as experimental materials, and 20% PEG-6000 was used to simulate severe drought stress. The contents of auxin (IAA), zeatin nucleoside (ZR), gibberellin (GA) and abscisic acid (ABA) in roots and leaves of C.reticulata at 0, 24, 72 hours and 48 hours after rewater (re48 hours) under drought stress, and at the same time, the leaves were sequenced by transcriptome to screen differential genes.【Result】Under drought stress, the endogenous hormones in C.reticulata were all affected. The IAA content in leaves first increased and then decreased and then increased after rehydration, while the IAA content in roots continued to decrease and did not recover after rewater. The change trend of ZR content in leaves was the same as IAA, while that in roots was opposite to that in leaves.GA content in leaves increased continuously during stress and rewater, while GA content in roots increased during stress and decreased after rewater. The change trend of ABA content in leaves was similar to IAA, and ABA content in roots continued to increase during stress, and then decreased after rewater, which was similar to the change trend of GA content in roots.A total of 33 349 differentially expressed genes were screened from the transcriptome sequencing results of C.reticulata, which were significantly enriched in plant hormone transduction, phenylpropionic acid biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, photosynthesis and other pathways at four time points. Drought stress induced the expression of 46 differential genes in plant hormone signal transduction pathway. Four gene modules were identified by weighted gene co-expression network analysis (WGCNA), and the transcription group was correlated with the contents of the four hormones. Two key gene modules with high correlation with hormone response were screened, including 2769 and 2502 genes respectively. The top 5% genes in the key modules were selected for co-expression analysis, and six key genes (SDH1-1, PETC, VHA-A3, FtsH, chlD, TL17) and five transcription factors (IAA9, NAC, Trihelix, SWI/SNF, NF-YB) were obtained.【Conclusion】Drought stress affects the changes of endogenous hormone content and the expression of related pathway genes. In the study, two co-expression modules closely related to drought stress response are also identified. It is found that genes such as SDH1-1, PETC, VHA-A3, FtsH, chlD, TL17 and transcription factors such as IAA9, NAC, Trihelix, SWI/SNF, NF-YB play an important role in the response of endogenous hormones in C.reticulata under drought stress. [ABSTRACT FROM AUTHOR]

Bromus sterilis L. (barren brome) is one of the most economically important noxious grass weeds in the winter cereal fields of Europe. Its ecological behaviour in this agro-climatic region should be assessed for effective weed control strategies. The present study was conducted to assess the dormancy and germination response of the B. sterilis population from the Czech Republic under thermal, light, and stress conditions. The dormancy loss experiment revealed that seeds exposed to the light regime showed a remarkably lower percentage of germination, and under alternating temperatures of 10/20 °C in dark conditions, rapid loss of primary dormancy was observed. This population was found to germinate across a wide temperature range of 5-35 °C, with the highest germination rate at 25 °C (T50 = 1.14 days in dark, 1.21 days in light) and the germination time increased with decreasing temperatures below 25 °C. Further, due to fitness advantage, herbicide-resistant (R) biotypes were found to be more stress-tolerant than susceptible (S) biotypes under salinity and drought conditions. In the highest stress conditions, the germination of S biotypes was negligible, while R biotypes can germinate under high stress, but germination decreased below 25 °C. The current findings may add value to effective weed control strategies using prediction models based on seed dormancy and germination values under different hydrothermal conditions. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effect of traffic stress by soil compaction on zoysiagrass by analyzing the aerial and underground parts and hyperspectral analysis. Zoysiagrass plants were subjected to a compaction strength gradient from 35 to 80 kgf/cm² to confirm the compaction resistance and recoverable limit and measure the physiological change during stress. Changes in leaf color, photosynthesis, and hyperspectral reflectance due to continuous weak and strong traffic stress were measured, and vegetation indices were evaluated for the critical traffic stress injury assessment. As a result, the stem of the zoysiagrass was severely damaged up to 70 kgf/cm² based on soil hardness. The recoverable limit strength of soil compaction was 55 kgf/cm² under weak response pressure conditions. Collectively, our results show that the damage of weak compaction strength on the zoysiagrass was quickly recovered after the stop of traffic stress, especially since the growth of the underground part was increased by weak traffic stress. However, if the compaction strength above 65 kgf/cm² lasted for a long time, the growth of the underground part is limited by lowering the energy supply for the recovery occurred, in turn, the recovery occurred slowly after the compaction was stopped. Among the vegetation indices obtained from hyperspectral data, pigment specific simple ratio for chlorophyll a (PSSRa), pigment specific simple ratio for chlorophyll b (PSSRb), and pigment specific simple ratio for carotenoids (PSSRc) were effective in evaluating the damage of traffic stress. [ABSTRACT FROM AUTHOR]

Background: The behavior of Abscisic acid (ABA) as a stress phytohormone may be involved in mechanisms leading to tolerance and survival in adverse environmental conditions such as drought stress. Methods: Here, we evaluated ABA-mediated responses at physio-biochemical and molecular levels in drought-stressed seedlings of two different Desi-type chickpea genotypes (10 as a tolerant genotype and 247 as a sensitive one). Results: Under drought stress, two chickpea genotypes showed a decrease in their relative water content (RWC), and the intense decrease was related to the sensitive genotype (73.9%) in severe stress. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) concomitant with the severity of stress increased in genotypes and the higher increase was in the sensitive genotype (5.8-fold and 3.43-fold, respectively). In the tolerant genotype, the enhanced accumulation of total phenolic content (1.75-fold) and radical scavenging action, based on 1,1-diphenyl-2-picrylhydrazyl test (DPPH), (1.69-fold) were simultaneous with ABA accumulation (1.53-fold). In the tolerant genotype, transcriptional analysis presented upregulation of Zeaxanthin epoxidase (ZEP) (1.35-fold), 9-cis-epoxycarotenoid dioxygenase (NCED) (5.16-fold), and Abscisic aldehyde oxidase (AAO) (1.52-fold compared to control conditions) genes in severe stress in comparison with mild stress. The sensitive genotype had a declining trend in total chlorophyll (up to 70%) and carotenoid contents (36%). The main conclusion to be drawn from this investigation is that ABA with its regulatory effects can affect drought tolerance mechanisms to alleviate adverse effects of unsatisfactory environmental conditions. Conclusions: In this paper, we tried to indicate that drought stress induces overexpression of genes triggering ABA-mediated drought responses simultaneously in two genotypes while more increment expression was related to the tolerant genotype. At first thought, it seems that the tolerant genotype compared to the sensitive genotype has a genetically inherent ability to cope with and drop adverse effects of drought stress through over-accumulation of ABA as drought. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to analyze the impact of varying degrees of drought stress treatments on the physiological parameters of Indigofera pseudotinctoria, preliminarily evaluate the drought-resistant physiological responses of these materials, and provide a foundational reference for the selection and genetic improvement of drought-resistant germplasm in I. pseudotinctoria. [Method] 36 wild J. pseudotinctoria germplasm resources collected in Chongqing area were used as experimental materials. Pot cultivation was used to start drought treatment when 1. pseudotinctoria seedlings grew to the 90th day, and measure the content of osmoregulatory substances, relative water content, and antioxidant enzyme activity in the leaves of I. pseudotinctoria under 0 days of stress (control group CK, the relative soil water content was 80%-85% of the field water capacity), 7 days of stress (moderate drought, soil relative moisture content was 40%-50% of the field water capacity), and 14 days of stress (severe drought, soil relative moisture content was 20%-25% of the field water capacity). Drought resistance coefficients, membership functions and cluster analysis were applied for a comprehensive evaluation of drought resistance. [Result] Under drought stress conditions, we observed a wide variation in physiological responses among the 36 1. pseudotinctoria germplasms, leading to significant differences in their drought resistance capabilities. Comparative analysis of mean values for various parameters showed that, in comparison to the control group, osmotic adjustment substances such as malondialdehyde (MDA), soluble protein (SP), and proline (Pro) increased with the severity of drought. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) exhibited a convex trend as drought severity intensified, while relative water content (RWC) decreased with increasing drought stress. Among the seven parameters measured, peroxidase (POD) activity showed the largest coefficient of variation, while relative water content (RWC) displayed the smallest variation. Using membership function analysis, comprehensive D-value assessment, and cluster analysis, we categorized the drought resistance of the 36 1. pseudotinctoria germplasms into two distinct groups: Drought-resistant (comprising 8 germplasms) and sensitive (comprising 28 germplasms). Further examination of physiological indicators between these two groups revealed that drought-resistant germplasms exhibited higher antioxidant enzyme activity and osmotic adjustment substance Pro content compared to their sensitive counterparts. Conclusion] Under drought stress conditions, the physiological responses of the 36 1. pseudotinctoria germplasm resources displayed significant diversity and variation. Among the 36 1. pseudotinctoria germplasms, 8 germplasms were classified as drought-resistance by a comprehensive evaluation analysis. [ABSTRACT FROM AUTHOR]

This paper highlights the evolution and impact of the SWAP model (Soil – Water – Atmosphere – Plant), which was initiated by R.A. Feddes and colleagues fifty years ago, in 1974. Since then, the SWAP model has played a crucial role in the advancement of agrohydrology. This paper highlights some major advances that have been made, especially focussing on the last fifteen years. The domain of the SWAP model deals with the simulation of the soil water balance in both unsaturated and saturated conditions. The model solves the Richards equation using the water retention and hydraulic conductivity functions as described by the Van Genuchten – Mualem equations. Bimodal extensions of the Van Genuchten - Mualem relationships have been implemented, as well as modifications near saturation and addressing hysteresis. An important sink term in the Richards equation is root water uptake. Crop development plays an important role in a robust simulation of root water uptake. That is why a link has been made with the dynamic crop growth model WOFOST. Instead of using a prescribed crop development, a distinction between potential and actual crop development is calculated by reducing the potential photosynthesis as a result of water or oxygen stress. Since the early days of SWAP, empirical and macroscopic concepts have been used to simulate root water uptake. Recently two process-based concepts of root water uptake and oxygen stress have also been implemented. Another important sink-source term in the Richards equation is the interaction with artificial drains. In SWAP, drainage can be simulated by either using prescribed or simulated drain heads and simulation of controlled drainage with subirrigation is possible. Finally, we briefly elaborate on three studies using SWAP: water stresses in agriculture in the Netherlands, regional water productivity in China, and controlled drainage with subirrigation. We finish discussing promising developments for the near future.

Key message: PtrANR1 positively regulates plant drought tolerance by increasing proline level and reducing ROS accumulation. PtrANR1 directly activates PtrAUX1 expression to promote root growth and improve plant drought tolerance. Citrus quality and yield are severely declined under drought stress. To date, the effects of MADS-box family transcription factors (TFs) on plant drought resistance have made some progress. However, whether MADS-box family TFs are associated with citrus drought response has remained unclear. The current paper identified a MADS-box family gene PtrANR1 encoding anthocyanidin reductase from trifoliate orange. PtrANR1 exhibits high identities with ANR1 proteins found in various plants. PtrANR1 possesses two conserved domains known as MADS and kertanin-like domains. PtrANR1 is a nuclear protein which has transactivation activity. A significant induction of PtrANR1 transcript was detected in leaves and roots of trifoliate orange treated with PEG6000 and ABA. Under drought stress, Arabidopsis ectopic overexpressing PtrANR1 exhibited obviously elevated contents of proline, ABA and IAA, better developed root, enhanced antioxidant enzyme activities, as well as notably reduced accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS) compared with WT plants. However, opposite change trends of these physiological indices were detected in PtrANR1 homolog silencing lemon. Furthermore, transgenic Arabidopsis displayed significantly increased expression levels in genes associated with ABA, IAA and proline production, IAA polar transport, ROS elimination and drought response. However, these genes exhibited noticeably decreased transcript levels in PtrANR1 homolog silencing lemon. Moreover, PtrANR1 could increase IAA content and promote root growth by binding to GArG-box in the promoter of PtrAUX1 to activate its transcript. These findings indicated that PtrANR1 had a beneficial impact on plant drought resistance through promoting root development, increasing proline accumulation and scavenging of ROS. [ABSTRACT FROM AUTHOR]

This paper highlights the evolution and impact of the SWAP model (Soil – Water – Atmosphere – Plant), which was initiated by R.A. Feddes and colleagues fifty years ago, in 1974. Since then, the SWAP model has played a crucial role in the advancement of agrohydrology. This paper highlights some major advances that have been made, especially focussing on the last fifteen years. The domain of the SWAP model deals with the simulation of the soil water balance in both unsaturated and saturated conditions. The model solves the Richards equation using the water retention and hydraulic conductivity functions as described by the Van Genuchten – Mualem equations. Bimodal extensions of the Van Genuchten - Mualem relationships have been implemented, as well as modifications near saturation and addressing hysteresis. An important sink term in the Richards equation is root water uptake. Crop development plays an important role in a robust simulation of root water uptake. That is why a link has been made with the dynamic crop growth model WOFOST. Instead of using a prescribed crop development, a distinction between potential and actual crop development is calculated by reducing the potential photosynthesis as a result of water or oxygen stress. Since the early days of SWAP, empirical and macroscopic concepts have been used to simulate root water uptake. Recently two process-based concepts of root water uptake and oxygen stress have also been implemented. Another important sink-source term in the Richards equation is the interaction with artificial drains. In SWAP, drainage can be simulated by either using prescribed or simulated drain heads and simulation of controlled drainage with subirrigation is possible. Finally, we briefly elaborate on three studies using SWAP: water stresses in agriculture in the Netherlands, regional water productivity in China, and controlled drainage with subirrigation. We finish discussing promising developments for the near future. • Advances in soil-vegetation-atmosphere transfer modelling in the SWAP model. • Coupling of soil water dynamics with dynamic crop growth model. • Process-based root water uptake and oxygen uptake functions. • Climate-adaptive drainage with subirrigation. [ABSTRACT FROM AUTHOR]

Sexual reproduction through seeds is an effective way to renew plant populations and increase their genetic diversity, but seed germination process is complicated and relatively difficult due to the restriction of environmental conditions. Wetland plants that reproduce sexually through seeds may be affected by changes in moisture and temperature. This study aims to explore the ecological adaptation strategies of seed germination of Lilium concolor var. megalanthum under different hydrothermal conditions. Controlled experiments were conducted to investigate the germination performance of L. concolor var. megalanthum seeds at different temperatures (10°C, 15°C, 20°C, 25°C, and 30°C) and simulated drought stress conditions using PEG-6000 solutions (0%, 5%, 10%, 15%, and 20%). The results showed that temperature, drought stress, and their interaction significantly affected the days to first germination, germination percentage, coefficient of germination rate, germination energy, germination index, and vigor index of seeds (p<0.01). The germination percentage, germination index, and vigor index of seed were significantly higher at 25°C compared to other temperatures (p<0.01). The interaction between low temperature and drought stress significantly delayed the days to first germination. The inhibition of drought stress on seed germination was enhanced by PEG-6000 solution under high temperature. Under the conditions of 25°C and 5% PEG-6000 solution concentration, seeds of L. concolor var. megalanthum exhibited optimal germination parameters. At 10°C and 15°C, the seeds exhibited the highest tolerance to PEG-6000-simulated drought stress. Rehydration germination results showed that extreme temperatures and drought stress conditions inhibit seed germination of L. concolor var. megalanthum without damaging seed structure. The germination pattern of seeds under variable temperature and drought stress conditions reflects their adaptive strategies developed over longterm evolution to cope with the environmental conditions. [ABSTRACT FROM AUTHOR]

Fruit photosynthesis occurs in an internal microenvironment seldom encountered by a leaf (hypoxic and extremely CO2-enriched) due to its metabolic and anatomical features. In this study, the anatomical and photosynthetic traits of fully exposed green fruits of Quercus coccifera L. were assessed during the period of fruit production (summer) and compared to their leaf counterparts. Our results indicate that leaf photosynthesis, transpiration and stomatal conductance drastically reduced during the summer drought, while they recovered significantly after the autumnal rainfalls. In acorns, gas exchange with the surrounding atmosphere is hindered by the complete absence of stomata; hence, credible CO2 uptake measurements could not be applied in the field. The linear electron transport rates (ETRs) in ambient air were similar in intact leaves and pericarps (i.e., when the physiological internal atmosphere of each tissue is maintained), while the leaf NPQ was significantly higher, indicating enhanced needs for harmless energy dissipation. The ETR measurements performed on leaf and pericarp discs at different CO2/O2 partial pressures in the supplied air mixture revealed that pericarps displayed significantly lower values at ambient gas levels, yet they increased by ~45% under high CO2/O2 ratios (i.e., at gas concentrations simulating the fruit's interior). Concomitantly, NPQ declined gradually in both tissues as the CO2/O2 ratio increased, yet the decrease was more pronounced in pericarps. Furthermore, net CO2 assimilation rates for both leaf and pericarp segments were low in ambient air and increased almost equally at high CO2, while pericarps exhibited significantly higher respiration. It is suggested that during summer, when leaves suffer from photoinhibition, acorns could contribute to the overall carbon balance, through the re-assimilation of respiratory CO2, thereby reducing the reproductive cost. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) and other reactive nitrogen species (RNS) are considered to be signaling molecules in higher plants involved in the regulation of growth and development processes. However, the molecular mechanisms of their formation, removal, and participation in plant responses to adverse environmental stimuli remain largely unclear. Therefore, the aim of this study was to assess the influence of selected single stresses and combined stresses (i.e., Rhopalosiphum padi L. aphid infestation, drought, aphid infestation, and drought) and post-stress recovery on the contents of NO and peroxynitrite anion (ONOO−), as well as the levels of mRNA and protein nitration (i.e., the 8-nitroguanine and protein 3-nitrotyrosine amounts, respectively), in maize seedlings (Zea mays L.). Moreover, the expression patterns of the two tested genes (nos-ip, encoding nitric oxide synthase-interacting protein, and nr1, encoding nitrate reductase 1) involved in NO metabolism in maize plants were quantified. We identified significant intervarietal, time-course, and stress-dependent differences in the levels of the quantified parameters. Under the investigated stress conditions, the aphid-resistant Waza cv. seedlings were characterized by a higher and earlier NO accumulation and mRNA nitration level and an increased expression of the two target genes (nos-ip and nr1), compared to the aphid-susceptible Złota Karłowa cv. seedlings. Conversely, the Złota Karłowa plants responded with a greater elevation in the content of ONOO− and protein 3-nitrotyrosine than the Waza cv. plants The multifaceted role of NO and its derivatives in maize plants challenged by single and combined stresses, as well as during post-stress recovery, is discussed. [ABSTRACT FROM AUTHOR]

Drought and salinity are significant challenges to global food security. This study investigated the interactive impacts of Piriformospora indica inoculation with salinity and drought stresses on rice. Two greenhouse experiments were conducted. The first experiment evaluated two P. indica inoculation levels and three salinity levels (0-, 50-, and 100-mM sodium chloride), while the subsequent experiment assessed two inoculation levels under three drought intensities (25%, 50%, and 100% of available water content). P. indica spores were inoculated following optimized seed disinfection and germination processes. The shoot and root biomass under salinity stress were consistently higher in inoculated plants compared to controls. Sodium concentrations in shoots and roots exhibited an overall upward trend, with the trend being less pronounced in inoculated plants due to increased potassium uptake. Under salinity stress, nitrogen, magnesium, and calcium concentrations significantly increased in inoculated plants. With increasing salinity, there was a significant increase in catalase enzyme activity and soluble carbohydrate concentrations across all treatments, with a greater increase in inoculated plants. Plants under drought stress experienced reduced root and shoot biomass, but inoculated plants maintained higher biomass. Increasing drought stress led to decreased nitrogen, magnesium, and calcium concentrations in all treatments, with the reduction being less severe in inoculated plants. Catalase enzyme activity and carbohydrate increased with rising drought stress, with the increase being more pronounced in inoculated plants compared to non-inoculated ones. By promoting plant growth, nutrient uptake, and stress tolerance, P. indica inoculation has a significant potential to enhance crop productivity in extreme climate conditions. [ABSTRACT FROM AUTHOR]

Background: Drought stress is a major limiting factor that affects forage yields, and understanding the drought resistance mechanism of plants is crucial for improving crop yields in arid areas. Alfalfa (Medicago sativa L.) is the most important legume plant, mainly planted in arid and semi-arid areas. However, the adaptability of alfalfa to drought stress and its physiological and molecular mechanisms of drought resistance remains unclear. Results: In this study, we analyzed the physiological and transcriptome responses of alfalfa cultivars with different drought resistances (drought-sensitive Gannong No. 3 (G3), drought-resistant Gannong No. 8 (G8), and strong drought-resistant Longdong (LD)) under drought stress at 0, 6, 12, and 24 h. LD had higher catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities and a higher soluble protein content, lower malondialdehyde (MDA) content, a lower O2·− production rate, and a lower H2O2 content than G8 and G3 (P < 0.05). The functional enrichment analysis, temporal expression pattern analysis, and weighted gene co-expression network analysis (WGCNA) of the differentially expressed genes (DEGs) showed phenylpropanoid biosynthesis, flavonoid biosynthesis, starch and sucrose metabolism, glycolysis/gluconeogenesis, glutathione metabolism, and biosynthesis of amino acid responses to drought stress in alfalfa. The differential expression of genes during phenylpropanoid biosynthesis, starch and sucrose metabolism, and the glutathione metabolism pathway was further studied, and it was speculated that PAL, COMT, 4CL, CCR, CAD, HXK, INV, SUS, WAXY, AGP, GST, and APX1 played important roles in the alfalfa drought stress response. Conclusions: The aim of this study was to enhance alfalfa drought resistance by overexpressing positively regulated genes and knocking out negatively regulated genes, providing genetic resources for the subsequent molecular-assisted breeding of drought-resistant alfalfa crops. [ABSTRACT FROM AUTHOR]

Drought is a major stress that hinders plant growth and causes water stress, posing a significant threat to global food security. While nanotechnology, particularly the use of nanoparticles such as TiO2, offers a promising solution by enhancing plants' resilience to drought stress, improving nutrient absorption, and promoting growth under adverse conditions, its application in viticulture remains underexplored. The objective of this research was to investigate the effects of titanium dioxide nanoparticles (TiO2-NPs; 100, 10, 1, and 0 ppm (control)) on various physiological, biochemical, and morphological parameters in grapevine saplings. Three different rootstock varieties, 41 B/Crimson Seedless (CS), 1103 P/CS, and 5 BB/CS, were included in the experiment to assess how rootstock variety influences the response of grapevine saplings to TiO2-NPs under drought stress (40–50%) and well-irrigated (90–100%) conditions. Young vines grown in pots under greenhouse conditions were used in this study. Applications of 10 ppm TiO2-NPs improved growth parameters and the SPAD index and enhanced stomatal conductance, relative water content, and protein content in grapevine saplings under both drought and well-irrigated conditions. Conversely, oxidative stress parameters, including the membrane damage index, hydrogen peroxide, drought index, and lipid peroxidation levels, were significantly reduced following 10 ppm TiO2-NP applications under drought conditions. Furthermore, total phenolic content, proline content, and ascorbate peroxidase, catalase, and superoxide dismutase activities, which increased significantly with drought stress, were reduced to lower levels, paralleling the alleviation of drought-induced oxidative stress. Our results suggest that the primary role of TiO2 nanoparticles in enhancing drought tolerance is due to their beneficial effects in alleviating damage caused by drought stress. This finding applies not only to grapevines but may also be relevant for other agricultural crops. [ABSTRACT FROM AUTHOR]

Ginkgo biloba, usually referred to as a "living fossil," is widely planted in many countries because of its medicinal value and beautiful appearance. Owing to ginkgo's high resistance to drought stress, ginkgo seedlings can even survive withholding water for several days without exhibiting leaf wilting and desiccation. To assess the physiological and transcriptomic mechanisms involved in the drought stress and re-watering responses of Ginkgo biloba, ginkgo seedlings were subjected to drought treatment for 15 d (D_15 d) and 22 d (D_22 d) until they had severely wilted, followed by re-watering for 3 d (D_Re3 d) to restore normal growth. Variations in physiological characteristics (relative water content, malondialdehyde (MDA) content, stomatal aperture, and antioxidant enzyme activity) during drought and re-watering were assessed. In total, 1692, 2031, and 1038 differentially expressed genes (DEGs) were upregulated, while 1691, 2820, and 1910 were downregulated in D_15 d, D_22 d, and D_Re3 d, respectively, relative to the control. Three pathways, namely, plant hormone signal transduction, plant–pathogen interaction, and the plant MAPK signaling pathway, were enriched during drought stress and re-watering. The DEGs involved in plant hormone signal transduction pathways (those of IAA, CTK, GA, ABA, ETH, BR, SA, and JA) and the major differentially expressed transcription factors (TFs; MYB, bHLH, AP2/ERF, NAC, WRKY, and bZIP) were identified. Quantitative real-time PCR revealed six TFs as positive or negative regulators of drought stress response. These phenotype-related physiological characteristics, DEGs, pathways, and TFs provide valuable insights into the drought stress and re-watering responses in G. biloba. [ABSTRACT FROM AUTHOR]

Drought stress inhibits oat growth and yield. The application of fulvic acid (FA) can improve the drought resistance of oats, but the corresponding molecular mechanism of FA-mediated drought resistance remains unclear. Here, we studied the effects of FA on the drought tolerance of oat leaves through physiological, transcriptomic, and metabolomics analyses, and identified FAinduced genes and metabolites related to drought tolerance. Physiological analysis showed that under drought stress, FA increased the relative water and chlorophyll contents of oat leaves, enhanced the activity of antioxidant enzymes (SOD, POD, PAL, CAT and 4CL), inhibited the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and dehydroascorbic acid (DHA), reduced the degree of oxidative damage in oat leaves, improved the drought resistance of oats, and promoted the growth of oat plants. Transcriptome and metabolite analyses revealed 652 differentially expressed genes (DEGs) and 571 differentially expressed metabolites (DEMs) in FA-treated oat leaves under drought stress. These DEGs and DEMs are involved in a variety of biological processes, such as phenylspropanoid biosynthesis and glutathione metabolism pathways. Additionally, FA may be involved in regulating the role of DEGs and DEMs in phenylpropanoid biosynthesis and glutathione metabolism under drought stress. In conclusion, our results suggest that FA promotes oat growth under drought stress by attenuating membrane lipid peroxidation and regulating the antioxidant system, phenylpropanoid biosynthesis, and glutathione metabolism pathways in oat leaves. This study provides new insights into the complex mechanisms by which FA improves drought tolerance in crops. [ABSTRACT FROM AUTHOR]

Drought stress (DS) adversely affects a plant’s development and growth by negatively altering the plant’s physio-biochemical functions. Previous investigations have illustrated that seed priming with growth regulators is an accessible, affordable, and effective practice to elevate a plant’s tolerance to drought stress. Melatonin (MT) is derived from the precursor tryptophan and can improve germination, biomass, and photosynthesis under stress conditions. The current study examined the effect of melatonin seed priming on two wheat cultivars (Fakhar-e-Bhakkar and Akber-19) cultivated under severe drought conditions (35% FC). There were 6 levels of melatonin (i.e., M0 = control, M1 = 1 mg L− 1, M2 = 2 mg L− 1, M3 = 3 mg L− 1, M4 = 4 mg L− 1 and M5 = mg L− 1) which were used for seed priming. Our results confirmed that seed priming with M2 = 2 mgL− 1 concentration of MT alleviates the negative effects of DS by boosting the germination rate by 54.84% in Akber-19 and 33.33% in Fakhar-e-Bhakkar. Similarly, leaf-relative water contents were enhanced by 22.38% and 13.28% in Akber-19 and Fakhar-e-Bhakkar, respectively. Melatonin pre-treatment with 2 mgL− 1 significantly enhanced fresh and dry biomass of shoot and root, leaf area, photosynthetic pigments, osmoprotectants accumulation [total soluble proteins (TSP), total free amino acids (TFAA), proline, soluble sugars, glycine betaine (GB)] and lowered the amount of malondialdehyde (MDA) and hydrogen peroxide (H2O2) production by elevating antioxidants [Ascorbic acid, catalase (CAT), Phenolics, peroxidase (POD) and superoxide dismutase (SOD)] activity under drought stress (DS). Meanwhile, under control conditions (NoDS), the melatonin treatment M1 = 1 mgL− 1 effectively enhanced all the growth-related physio-biochemical attributes in both wheat cultivars. In the future, more investigations are suggested on different crops under variable agroclimatic conditions to declare 2 mgL− 1 melatonin as an efficacious amendment to alleviate drought stress. [ABSTRACT FROM AUTHOR]

Drought is increasingly becoming a production constraint in wheat world-wide. Arbuscular mycorrhizal fungi (AMF)-bread wheat symbiosis has been shown to improve the tolerance under drought stress. The objective of this study was to determine the effects of AMF inoculation on yield attributes (spike number per plant, spike weight per plant, number of grains per spike, grain weight per spike and 1000 grain weight) and protein quantity and quality in two bread wheat cultivars (PAN3497 and SST806) grown under drought stress. Plant growth was significantly reduced due to drought stress in both cultivars. Shoot dry weight was significantly increased (23%) due to AMF inoculation in SST806. AMF inoculation caused a further significant increase of protein content in both cultivars (10.70% and 13.42% in PAN3497 and SST806, respectively). Low molecular weight (LMW) glutenin was significantly decreased in PAN3497 under drought stress. However, the monomeric proteins were significantly increased by drought and/or a combination of drought and AMF inoculation in both cultivars. In cultivar SST806, significant reduction of polymeric protein was observed due to application of both AMF (6%) and a combination of AMF with drought stress (4%). Regarding the two-dimensional separation of the gluten proteins, drought had the largest effect on protein spots, with AMF causing up-regulation of only some spots. SST806 was generally more drought tolerant than PAN3497. [ABSTRACT FROM AUTHOR]

Olive trees are known as one of the most iconic crops in the world. Considering the increasing water deficit worldwide, implementing some profitable and empirical strategies can be inevitable upon exposure to drought stress. Therefore, the present study aimed at clarifying the beneficial role of exogenously foliar application of Fe2O3 modified carbon nitride nanostructures (control, FeSO4, C3N4 and Fe2O3/g-C3N4) to "Shengeh" olive cultivars grown at different watering levels (100, 75, and 50% ET) in two experimental years (2022 and 2023) and the pomological attributes, physiological and biochemical changes happening in the treated leaves and fruits were discussed. The results indicated that drought stress caused a significant decline in pomological attributes in this experiment, and treatments could remarkably make up for this damage. Overall, Fe2O3/g-C3N4 outperformed as compared FeSO4 and C3N4 alone, which were also efficacious in conferring tolerance to the water deficit stress. Conversely, severe drought stressed-olive fruits showed higher oil content percent in the fresh matter and water use efficiency (WUE) in oil by 30% and 52.5%, respectively, as an average of results of two years, and after Fe2O3/g-C3N4, these features in olive plants subjected to severe drought improved by an average of 35% over two years. Ca2+ and K+ in olive plants under severe drought stress declined by 50% and 83% in 2022 and 46% and 24% in 2023, while Na+ increased in the plants exposed to 50%ET stress by 48% and 57% in two successive experimental years respectively. The application of Fe2O3/g-C3N4 remarkably improved the contents of Ca2+ and K+ by 101.5% and 369%, respectively, as an average of two years. Conversely, this beneficial treatment led to a significant decline in Na+ levels by 30% in 2022 and 2% in 2023 under stressful conditions. Moreover, it decreased the 'osmolytes' content, caused a smaller decline in chlorophyll levels, and resulted in higher relative water content occurring in the treated olive leaves. The reduction of oxidative markers was a result of the increased enzymatic activity after the use of Fe2O3/g-C3N4. Therefore, this treatment is a promising strategy to achieve improved resistance in olive plants in the future. [ABSTRACT FROM AUTHOR]

Drought is a major abiotic stress factor that reduces agricultural productivity. Understanding the molecular regulatory network of drought response in winter rape is of great significance for molecular Brassica rapa. In order to comprehensively analyze the network expression of DEGs and DEMIs in winter rape under drought stress, in this study we used Longyou 7 as the experimental material to identify DEGs and DEMIs related to drought stress by transcriptome and miRNA sequencing. A total of 14–15 key differential mRNA genes related to drought stress and biological stress were screened out under different treatments in the three groups. and 32 differential miRNAs were identified through targeted regulatory relationships, and the mRNA expression of 20 target genes was negatively regulated by the targeting regulatory relationship. It is mainly enriched in starch and sucrose metabolism, carbon metabolism and other pathways. Among them, gra-MIR8731-p3_2ss13GA18GA regulated the expression of multiple mRNAs in the three treatments. miRNA is mainly involved in the drought resistance of Chinese cabbage winter rape by regulating the expression of target genes, such as starch and sucrose metabolism, amino acid biosynthesis, and carbon metabolism. These miRNAs and their target genes play an indispensable role in winter rapeseed drought stress tolerance regulation. [ABSTRACT FROM AUTHOR]

Drought stress seriously threatens plant growth. The improvement of plant water use efficiency (WUE) and drought tolerance through stomatal regulation is an effective strategy for coping with water shortages. Epidermal patterning factor (EPF)/EPF-like (EPFL) family proteins regulate stomatal formation and development in plants and thus contribute to plant stress adaptation. Here, our analysis revealed the presence of 14 PeEPF members in the Populus euphratica genome, which exhibited a relatively conserved gene structure with 1–3 introns. Subcellular localisation prediction revealed that 9 PeEPF members were distributed in the chloroplasts of P. euphratica, and 5 were located extracellularly. Phylogenetic analysis indicated that PeEPFs can be divided into three clades, with genes within the same clade revealing a relatively conserved structure. Furthermore, we observed the evolutionary conservation of PeEPFs and AtEPF/EPFLs in certain domains, which suggests their conserved function. The analysis of cis-acting elements suggested the possible involvement of PeEPFs in plant response to multiple hormones. Transcriptomic analysis revealed considerable changes in the expression level of PeEPFs during treatment with polyethylene glycol and abscisic acid. The overexpression of PeEPF2 resulted in low stomatal density in transgenetic lines. These findings provide a basis for gaining insights into the function of PeEPFs in response to abiotic stress. [ABSTRACT FROM AUTHOR]

Background: The frequency and severity of abiotic stress events, especially drought, are increasing due to climate change. The plant root is the most important organ for water uptake and the first to be affected by water limitation. It is therefore becoming increasingly important to include root traits in studies on drought stress tolerance. However, phenotyping under field conditions remains a challenging task. In this study, plants were grown in a hydroponic system with polyethylene glycol as an osmotic stressor and in sand pots to examine the root system of eleven spring barley genotypes. The root anatomy of two genotypes with different response to drought was investigated microscopically. Results: Root diameter increased significantly (p < 0.05) under polyethylene glycol treatment by 54% but decreased significantly (p < 0.05) by 12% under drought stress in sand pots. Polyethylene glycol treatment increased root tip diameter (51%) and reduced diameter of the elongation zone (14%) compared to the control. Under drought stress, shoot mass of plants grown in sand pots showed a higher correlation (r = 0.30) with the shoot mass under field condition than polyethylene glycol treated plants (r = -0.22). Conclusion: These results indicate that barley roots take up polyethylene glycol by the root tip and polyethylene glycol prevents further water uptake. Polyethylene glycol-triggered osmotic stress is therefore unsuitable for investigating root morphology traits in barley. Root architecture of roots grown in sand pots is more comparable to roots grown under field conditions. [ABSTRACT FROM AUTHOR]

Global water scarcity and extreme weather intensify drought stress, significantly reducing cotton yield and quality worldwide. Drought treatments are conducted using a population of chromosome segment substitution lines generated from E22 (G. hirsutum) and 3–79 (G. barbadense) as parental lines either show superior yields or fiber quality under both control and drought conditions. Fourteen datasets, covering 4 yields and 4 quality traits, are compiled and assessed for drought resistance using the drought resistance coefficient (DRC) and membership function value of drought resistance (MFVD). Genome‐wide association studies, linkage analysis, and bulked segregant analysis are combined to analyze the DR‐related QTL. A total of 121 significant QTL are identified by DRC and MFVD of the 8 traits. CRISPR/Cas9 and virus‐induced gene silencing techniques verified DRR1 and DRT1 as pivotal genes in regulating drought resistant of cotton, with hap3‐79 exhibiting greater drought resistance than hapE22 concerning DRR1 and DRT1. Moreover, 14 markers with superior yield and fiber quality are selected for drought treatment. This study offers valuable insights into yield and fiber quality variations between G. hirsutum and G. barbadense amid drought, providing crucial theoretical and technological backing for developing cotton varieties resilient to drought, with high yield and superior fiber quality. [ABSTRACT FROM AUTHOR]

Global warming causes heat and drought stress in plants, which affects crop production. In addition to osmotic stress and protein inactivation, reactive oxygen species (ROS) overaccumulation under heat and drought stress is a secondary stress that further impairs plant performance. Chloroplasts, mitochondria, peroxisomes, and apoplasts are the main ROS generation sites in heat- and drought-stressed plants. In this review, we summarize ROS generation and scavenging in heat- and drought-stressed plants and highlight the potential applications of plant nanobiotechnology for enhancing plant tolerance to these stresses. [ABSTRACT FROM AUTHOR]

The prevalence of drought events worldwide emphasizes the importance of screening and cultivating drought-adapted crops. In this study, 206 germplasm resources were used as materials, dry weight as target trait, and two genotyping methods as criteria to evaluate drought adaptability at the seedling establishment stage. The results showed a significant decrease in average dry weight of the tested germplasm resources (from 746.90 mg to 285.40 mg) and rich variation in the responses of dry weight among each genotype to drought (CV=61.14%). In traditional evaluation method, drought resistance coefficient (DC), geometric mean productivity index (GMP), mean productivity index (MP), stress susceptibility index (SSI), stress tolerance index (STI), and tolerance index (TOL) also exhibited diversity in tested genotypes (CV>30%). However, these indices showed varying degrees of explanation for dry weight under stress and nonstress environments and failed to differentiate drought adaptability among genotypes clearly. In new evaluation method, four stress indices were developed to quantify barley seedling production and stability capacities. Compared to traditional stress indices, the stress production index (SI) explained dry weight more comprehensively under stress conditions (R² = 0.98), while the ideal production index (II) explained dry weight better under non-stress conditions (R² = 0.89). Furthermore, the potential index (PI) and elasticity index (EI) eliminated disparities in traditional stress indices and comprehensively clarified the contribution of elasticity and potential to production capacity under drought stress. Ultimately, through grading evaluation and cluster analysis, the tested germplasm resources were effectively categorized, and 11 genotypes were identified as suitable for cultivation in arid areas. Overall, the comprehensive evaluation method based on the newly developed stress indices surpasses the traditional method in screening drought adaptability of crops and serves as a vital tool for identifying high-stability and high-production capacities genotypes in various environments, which is expected to provide practical guidance for barley planting and breeding in arid areas. [ABSTRACT FROM AUTHOR]

Enhancing crop drought tolerance is crucial for food security amid climate change. This study examines how 5‐aminolevulinic acid (ALA) and hydrogen sulfide (H2S) can improve drought resilience in tomato plants, which are essential for sustainable food production. Drought stress was induced using 12% PEG‐6000. Plants were pre‐treated with 25 mg L−1 ALA and 0.1 mg L−1 hypotaurine (HT), followed by 0.2 mM sodium hydrosulfide (NaHS) treatment to assess the effects on plant physiological effects over 10 days. Drought stress reduced plant dry weight, chlorophylls (a and b), Fv/Fm, leaf water potential, and relative water content, while increasing glycine betaine (GB) and proline levels. Additionally, drought stress elevated NADPH oxidase (NOX) and glycolate oxidase (GOX) activities, inducing oxidative stress and membrane damage. ALA and NaHS enhanced plant growth, photosynthesis, proline, GB, ALA content, ATP synthase, and ATPase activities, while mitigating NOX and GOX activities, thereby reducing O2·−$$ {\mathrm{O}}_2^{\cdotp -} $$ and H2O2 radicals. ALA alone boosted L‐DES activity, promoting H2S accumulation. However, ALA + HT reduced H2S levels, compromising ALA's efficacy. NaHS with ALA + HT reinstated positive effects by restoring H2S levels. Biochemical assays confirmed ALA and NaHS promoted H2S accumulation, bolstering antioxidants, mitigating lipid peroxidation, suggesting their drought resilience potential in tomatoes. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of salicylic acid and zinc sulfate on quality and quantity characters of green cumin (Cuminum cyminum) under different irrigation regimes, a field study was conducted at Fatholmobin Agro industry, Kashan, Iran. A split factorial experiment based on randomized complete block design with three replications was used. The main plots considered irrigation regimes (irrigation after 70, 100 and 130 mm cumulative evaporation from class A evaporation pan), and sub-plots considered two level of salicylic acid application (control and 1 mM) and three levels of zinc sulfate (control, 30 and 60 Kg.ha-1) as factorial. The results showed that with the increase in the irrigation interval, the yield and yield components decreased and the percentage of cumin essential oil increased. The grain yield in irrigation after 70, 100 and 130 mm cumulative evaporation treatments was 2659, 19525 and 1009 kg/ha, respectively. The application of salicylic acid and zinc sulfate both under control conditions and moisture stress led to an increase in yield and yield components. Although by delay in irrigation from 70 to 100 mm cumulative evaporation from class A evaporation pan, the grain yield decreased by 6%, with the combined application of 60 kg/ha of zinc sulfate and salicylic acid while reducing the effects of drought, the essential oil yield increased by 6.5 kg/ha. It was concluded that by irrigation the cumin after 100 mm cumulative pan evaporation with combined use of 60Kg.ha-1 zinc sulfate and 1 mM salicylic acid, water could be saved by 21.5% while increasing the yield of essential oil, the yield of seeds may decrease slightly under these conditions. [ABSTRACT FROM AUTHOR]

Millet, a vital and nutritionally dense cereal extensively cultivated in Sub-Saharan Africa, plays a key role in ensuring food security. This study investigates the starch synthase (SS) gene family, which is crucial for starch biosynthesis and influences various plant functions and stress responses. While the specific roles of SS genes in millet under drought conditions are not fully elucidated, this research provides a thorough analysis of the SS gene family in millet. A total of twelve millet SS genes (SiSSs) were identified and classified into four subfamilies (I–IV) through gene structure and phylogenetic analysis. The SiSS genes were unevenly distributed across millet chromosomes, with cis-acting elements associated with plant growth and stress defense being identified. Quantitative PCR (qPCR) revealed dynamic and varied expression patterns of SiSSs in different tissues under drought stress. Millet plants subjected to drought conditions showed higher tissue starch content and increased starch synthase activity compared to controls. Importantly, the expression levels of the twelve SiSSs were positively correlated with both starch content and synthase activity, suggesting their significant role in drought tolerance. This study enhances our understanding of the millet SS gene family and highlights the potential of these genes in breeding programs aimed at developing drought-resistant millet varieties. Further research is recommended to validate these findings and delve deeper into the mechanisms underlying drought tolerance. [ABSTRACT FROM AUTHOR]

The North Western Himalayan region, particularly the Kashmir valley, harbors a rich diversity of rice landraces, yet systematic studies on climate resilience are lacking. The present study was aimed at investigating the root traits and their interplay with shoot morphological and physiological traits under drought stress using seven indica and three japonica rice varieties released by SKUAST-Kashmir and their possible role in adaptive capacity to different environments. Significant variability was observed in root and shoot traits across the varieties. Root traits exhibited a wide phenotypic range, including rooting depth, fresh and dry weight, diameter, length, volume, surface area, and length density. Associations between root and shoot traits were identified, with notable correlations such as shoot weight with root shoot ratio, shoot length with root dry weight, diameter, and surface area, and tiller number with various root traits. Additionally, physiological traits like canopy temperature depression showed significant correlations with root depth and surface area. Principal component analysis (PCA) analysis grouped japonica type varieties together with a notable outlier, Chenab, due to its superior root traits among indica varieties. These findings emphasize the substantial contribution of root traits to productivity and advocate for their integration into varietal development processes. In view of the increasing evidences in crop plants about their role of root traits in defining plant productivity and reproductive fitness, study of root traits could provide valuable insights into the patterns of crop adaptation to diverse areas and growing environments. [ABSTRACT FROM AUTHOR]

Soluble inorganic pyrophosphatase (s-PPase), a pyrophosphate hydrolase, is crucial for various physiological processes including plant growth and development, metabolic functions, and responses to abiotic stresses. However, research on s-PPase in woody plants is limited. To investigate the potential role of soluble inorganic pyrophosphatase in Eucommia ulmoides Oliver (E. ulmoides) in drought stress, the E. ulmoides soluble inorganic pyrophosphatase 5 (EuSIP5) cDNA sequence was amplified via RT-PCR. A bioinformatic analysis suggested that EuSIP5 may be an unstable amphipathic protein predominantly localized in the cytoplasm. In E. ulmoides, the highest expression of the EuSIP5 gene was detected in the leaves and pericarp of male plants from April to October, and in the leaves in July and September. Under drought conditions, the expression of EuSIP5 in E. ulmoides leaves was significantly greater than that in the control. An overexpression vector containing EuSIP5 was constructed and introduced into Nicotiana tabacum L. cv. Xanthi (N. tabacum L.). Compared with that in wild-type (WT) plants, wilting in N. tabacum L. EuSIP5-overexpressing (OE) plants was delayed by 4 days under drought stress. Additionally, the expression levels of the drought-related genes DET2, CYP85A1, P5CS, ERF1, F-box, and NCED1 were elevated in the leaves of transgenic N. tabacum L. Moreover, the activities of the protective enzymes peroxidase, superoxide dismutase, and catalase were significantly greater, whereas the malondialdehyde content was lower in the transgenic plants than in the WT plants. These findings suggest that the introduction of the EuSIP5 gene into N. tabacum L. enhances drought-related gene expression, increases antioxidant capacity, and reduces oxidative stress damage, thereby improving drought resistance. [ABSTRACT FROM AUTHOR]

When applied under abiotic stress conditions, triacontanol (TRIA) is effective in regulating the physicochemical processes in plants through mechanisms of defence such as abscisic acid (ABA) signalling. However, TRIA's role in relation to ABA and stomatal opening is unclear. Therefore, the objective of this study was to evaluate the effects of TRIA and ABA and their combinations on different variables related to stomatal regulation in Solanum lycopersicum, which is subjected to drought stress, and on the leaf epidermis. The negative effects of stress and responses triggered by ABA were reversed in plants treated with TRIA. TRIA increased stomatal conductance and photosynthetic activity in the early hours, and it was determined that TRIA produced larger stomata than did the other treatments. Moreover, the chloroplasts of plants treated with TRIA were significantly smaller and more numerous than those of the control, which could improve CO2 diffusion efficiency and may be related to the regulation of stomatal opening and photosynthesis. Finally, the abaxial epidermis tests reaffirmed the inhibitory effects of TRIA on ABA on stomatal opening. These results confirm the important role of TRIA in regulating various processes in plants and processes triggered by ABA, such as those related to stomatal regulation. [ABSTRACT FROM AUTHOR]