Search

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]

[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]

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) 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]

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.

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]

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]

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is crucial in plant metabolism and responses to various abiotic stresses. In the glycolysis pathway, glyceraldehyde-3-phosphate (G3P) is oxidized to 1,3-bisphosphate glycerate (1,3-BPG) through the catalytic action of GAPDH. However, the GAPDH gene family in Quercus rubra has been minimally researched. In this study, we identified 13 GAPDH-encoding genes in Q. rubra through a bioinformatics analysis of genomic data. Evolutionary studies suggest that these QrGAPDH genes are closely related to those in Glycine max and Triticum aestivum. We conducted a comprehensive whole-genome study, which included predictions of subcellular localization, gene structure analysis, protein motif identification, chromosomal placement, and analysis of cis-acting regions. We also examined the expression of GAPDH proteins and genes in various tissues of Q. rubra and under drought stress. The results indicated diverse expression patterns across different tissues and differential expression under drought conditions. Notably, the expression of Qurub.02G290300.1, Qurub.10G209800.1, and Qrub.M241600.1 significantly increased in the leaf, stem, and root tissues under drought stress. This study provides a systematic analysis of QrGAPDH genes, suggesting their pivotal roles in the drought stress response of trees. [ABSTRACT FROM AUTHOR]

Paulownia fortunei (Seem.) Hemsl is a Paulownia Sieb.et tree of the family Scrophulariaceae. It has become an important short-to-medium-term fast-growing multi-purpose tree species in China due to its rapid growth, strong adaptability, and excellent material properties. MYB transcription factors in plants have numerous and diverse functions, playing important roles in various aspects such as plant stress response. To investigate the function of MYB transcription factors in Paulownia fortunei, this study used PCR technology to clone the PfMYB44 gene from Paulownia fortunei. The homology of PfMYB44 and SiMYB44 (Sesamum indicum) was the highest. Expression analysis results showed that PfMYB44 was expressed in the root, stem, young leaf, and mature leaf of Paulownia fortunei, with the highest content in the root. Cold, drought, hot, salt, and ABA treatments could increase the expression level of PfMYB44. Overexpression-PfMYB44 plants were constructed, and physiological and molecular analysis showed that PfMYB44 could positively regulate salt and drought stresses. Under drought stress, the expression levels of AtP5CS, AtCAT1, AtNCED3 and AtSnRK2.4 in transgenic lines were significantly induced. Salt stress induced the expression of AtNHX1, AtSOS1, AtSOS2 and AtSOS3 genes, and the relative expression levels of these genes in transgenic Arabidopsis were higher. In conclusion, the functional study of PfMYB44 laid a certain foundation for the study of Paulownia stress resistance, and was helpful to the study of its stress resistance mechanism and the cultivation of new stress resistance varieties. [ABSTRACT FROM AUTHOR]

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25–30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from −1 to −3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as −7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus' development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989–2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento. [ABSTRACT FROM AUTHOR]

Provenance trials provide a valuable opportunity to evaluate the impact of extreme events on growth and wood properties. In this study, we have evaluated 81 Norway spruce provenances, tested in three provenance trials established in the Romanian Carpathians in 1972. The response to drought of the Norway spruce provenances has been examined using the following tree resilience indices: resistance, recovery, resilience, and relative resilience. The relationship between climate and growth, the correlations between wood traits, and the coordinates of the origin and tree resilience indices were also analysed. In each provenance trial, there were significant differences between provenances and years regarding wood widths and latewood percentage (LWP). Regarding drought extreme events, the years when they occurred in all three provenance trials were 2000 and 2003. Significant differences between provenances for at least one tree resilience index have been found in all provenance trials, for the year 2000. By using subperiods of 25 years, changes in the relationship between climate and growth have been observed. Several provenances with high radial growth and good resistance and/or recovery have been identified. Provenances that performed better in common garden experiments could be used in assisted migration, even in the proximity of the current natural range. [ABSTRACT FROM AUTHOR]

Background: To optimize irrigation water use and productivity, understanding the interactions between plants, irrigation techniques, and fertilization practices is crucial. Therefore, the experiment aims to assess the effectiveness of two application methods of potassium humate combined with chelated zinc under partial root-zone drip irrigation techniques on maize nutrient uptake, yield, and irrigation water use efficiency across two irrigation levels. Methods: Open-field experiments were carried out in two summer seasons of 2021 and 2022 under alternate and fixed partial root-zone drip irrigation techniques to investigate their impacts at two irrigation levels and applied foliar and soil applications of potassium humate or chelated zinc in a sole and combinations on maize. Results: Deficit irrigation significantly increased hydrogen peroxide levels and decreased proline, antioxidant enzymes, carbohydrate, chlorophyll (a + b), and nutrient uptake in both partial root-zone techniques. The implementation of combined soil application of potassium humate and chelated zinc under drought conditions on maize led to varying impacts on antioxidant enzymes and nutritional status, depending on the type of partial root-zone technique. Meanwhile, the results showed that fixed partial root-zone irrigation diminished the negative effects of drought stress by enhancing phosphorus uptake (53.8%), potassium uptake (59.2%), proline (74.4%) and catalase (75%); compared to the control. These enhancements may contribute to improving the defense system of maize plants in such conditions. On the other hand, the same previous treatments under alternate partial root zone modified the defense mechanism of plants and improved the contents of peroxidase, superoxide dismutase, and the uptake of magnesium, zinc, and iron by 81.3%, 82.3%, 85.1%, 56.9%, and 80.2%, respectively. Conclusions: Adopting 75% of the irrigation requirements and treating maize plants with the soil application of 3 g l−1 potassium humate combined with 1.25 kg ha−1 chelated zinc under alternate partial root-zone technique, resulted in the maximum root length, leaf water content, chlorophyll content, yield, and irrigation water use efficiency. [ABSTRACT FROM AUTHOR]

Cytokinin oxidase/dehydrogenase (CKX) is the key enzyme that has been observed to catalyze irreversible inactivation of cytokinins and thus modulate cytokinin levels in plants. CKX gene family is known to have few members which are, expanded in the genome mainly due to duplication events. A total of nine MiCKXs were identified in Morus indica cv K2 with almost similar gene structures and conserved motifs and domains. The cis-elements along with expression analysis of these MiCKXs revealed their contrasting and specific role in plant development across different developmental stages. The localization of these enzymes in ER and Golgi bodies signifies their functional specification and property of getting modified post-translationally to carry out their activities. The overexpression of MiCKX4, an ortholog of AtCKX4, displayed longer primary root and higher number of lateral roots. Under ABA stress also the transgenic lines showed higher number of lateral roots and tolerance against drought stress as compared to wild-type plants. In this study, the CKX gene family members were analyzed bioinformatically for their roles under abiotic stresses. [ABSTRACT FROM AUTHOR]

Background: We aimed to gain insight into the response mechanism of alfalfa (Medicago sativa) to drought stress by recognizing and analyzing drought-responsive genes in the roots of different root types of alfalfa. The rhizomatous-rooted M. sativa cv.'Qingshui' (QS), tap-rooted M. sativa cv.'Longdong' (LD), and creeping-rooted M. varia cv. 'Gongnong No. 4' (GN) were used to analyze the transcriptome information and physiological characteristics of the root systems of the cultivars under simulated drought stress using PEG-6000. Results: It was found that aridity caused a significant increase in the content of osmotic stress substances and antioxidant enzyme activity. The content of malondialdehyde (MDA) in QS was lower than that in LD and GN under moisture stress, indicating a stronger accumulation capacity of osmotic regulatory substances. Based on sequencing results, 14,475, 9336, and 9243 upregulated DEGs from QS, LD, and GN were annotated into 26, 29, and 28 transcription factor families, respectively. QS showed more DEGs than LD and GN. KEGG enrichment analysis identified that DEGs were significantly enriched in metabolic pathways such as amino acid biosynthesis, phenylpropanoid biosynthesis, plant hormone signaling transduction, and MAPK pathways. This suggests a strong correlation between these pathways and drought stress. The results also show that genes associated with ABA hormone signaling (MS. gene93372, MS. gene072046, and MS. gene012975) are crucial for plant's adaptation to drought stress. Conclusions: These genes, such as serine/threonine protein kinases and abscisic acid receptors, play a crucial role in plant hormone signaling and MAPK pathways. They could serve as potential candidate genes for drought resistance research in alfalfa, providing a molecular foundation for studying drought resistance. [ABSTRACT FROM AUTHOR]

Background: Drought is a significant abiotic stress that adversely affects plant growth, development, and metabolic processes, thereby reducing plant yield, quality, and production, and threatening global food security. In recent years, nanotechnology has emerged as a promising strategy to overcome the existing environmental challenges and has been tested on some plant species. But it is still awaiting investigation for grapevines. The aim of this study was to investigate the potential of selenium nanoparticles (Se-NPs) to modulate some morphological, physiological, and biochemical parameters in grapevine saplings (5 BB/Crimson Seedless, 41 B/Crimson Seedless, and 1103 P/Crimson Seedless) under drought stress conditions. Results: In the study, Se-NP solutions at different concentrations (0 (control), 1, 10, and 100 ppm) were applied by the spray method to wet the entire green surface of grapevine saplings grown under well-irrigated (90–100% field capacity) and drought stress (40–50% field capacity) conditions. Our results showed that 10 ppm Se-NP concentration had the most positive effect, 1 ppm concentration showed limited effects, and 100 ppm concentration led to toxic effects, especially when combined with drought conditions. Se-NP applications at 10 ppm concentration improved the growth parameters (leaf number, leaf area, root fresh and dry weight, shoot fresh and dry weight, etc.) and increased the SPAD index of grapevine saplings under both normal and drought conditions. Additionally, 10 ppm Se-NP applications improved the relative water content (RWC) and stomatal conductance values, proportional to the increases in protein content. On the other hand, under drought conditions, the drought index, leaf temperature, membrane damage index, hydrogen peroxide (H2O2) content, and malondialdehyde (MDA) levels significantly decreased as a result of 10 ppm Se-NP applications, showing an opposite trend. Furthermore, the levels of proline, total phenolics, and antioxidant enzymes (CAT, SOD, and APX) that rose significantly due to drought stress were reduced by 10 ppm Se-NP applications, which also helped to lessen the oxidative stress caused by the drought. Conclusion: The study concluded that foliar application of Se-NPs at 10 ppm significantly enhances drought tolerance in grapevine saplings by improving antioxidant defense, proline and protein accumulation, and overall growth, while lower concentrations are less effective and higher concentrations can cause phytotoxicity. These findings indicate that Se-NPs applications may hold promise not only for grapevines but also for mitigating drought stress effects and improving productivity in other economically important fruit species, warranting further exploration across diverse crop systems. [ABSTRACT FROM AUTHOR]

Blue honeysuckle (Lonicera caerulea L.) is a deciduous shrub with perennial rootstock found in China. The objectives of this study were to explore the drought tolerance of blue honeysuckle, determine the effect of drought stress on two photosystems, and examine the mechanism of acquired drought tolerance. In this study, blue honeysuckle under four levels of simulated field capacity (100%, 85%, 75%, and 65% RH) was grown in split-root pots for drought stress treatment, for measuring the changes in chlorophyll content, photosynthetic characteristics, and leaf chlorophyll fluorescence parameters. The chlorophyll content of each increased under mild stress and decreased under moderate and severe stress. The net photosynthetic rate, transpiration rate, intercellular carbon dioxide concentration, and stomatal conductance of blue honeysuckle decreased with the increase in water stress. However, the water utilization rate and stomatal limit system increased under mild and moderate stress and decreased under severe stress. The maximum fluorescence (Fm), maximum photochemical efficiency, and quantum efficiency of photosystem II decreased with the decrease in soil water content, and the initial fluorescence increased significantly (p < 0.01). With the decrease in soil water content, the energy allocation ratio parameters decreased under severe drought stress. The main activity of the unit reaction center parameters first increased and then decreased. ABS/CSm, TRo/CSm, ETo/CSm, and REo/CSm gradually declined. After a comprehensive analysis, the highest scores were obtained under adequate irrigation (CK). Overall, we concluded that the water irrigation system of blue honeysuckle should be considered adequate. [ABSTRACT FROM AUTHOR]

In a tropical savanna climate like Thailand, cassava can be planted all year round and harvested at 8 to 12 months after planting (MAP). However, it is not clear how water limitation during the dry season without rain affects carbon assimilation, partitioning, and yield. In this field investigation, six cassava genotypes were planted in the rainy season (August 2021) under continuous irrigation (control) or subjected to drought for 60 days from 3MAP to 5MAP during the dry season (November 2021 to January 2022) with no irrigation and rainfall. After that, the plants were rewatered and continued growing until harvest at 12MAP. After 60 days of stress, there were significant reductions in the mean net photosynthesis rate (Pn), petiole, and root dry weight (DW), and slight reductions in leaf, stem, and tuber DW. The mean starch concentrations were reduced by 42% and 16% in leaves and tubers, respectively, but increased by 12% in stems. At 6MAP after 30 days of rewatering, Pn fully recovered, and stem starch was remobilized resulting in a dramatic increase in the DW of all the organs. Although the mean tuber DW of the drought plants at 6MAP was significantly lower than that of the control, it was significantly higher at 12MAP. Moreover, the mean tuber starch concentration at 12MAP of the drought plants (18.81%) was also significantly higher than that of the controls (16.46%). In the drought treatment, the high-yielding varieties, RY9, RY72, KU50, and CMR38-125-77 were similarly productive in terms of tuber DW and starch concentration while the breeding line CM523-7 produced the lowest tuber biomass and significantly lower starch content. Therefore, for cassava planted in the rainy season in the tropical savanna climate, the exposure to drought during the early growth stage was more beneficial than the continuous irrigation. [ABSTRACT FROM AUTHOR]

The SEVEN IN ABSENTIA (SINA) E3 ubiquitin ligase is widely involved in drought and salt stress in plants. However, the biological function of the SINA proteins in cotton is still unknown. This study aimed to reveal the function of GhSINAT5 through biochemical, genetic and molecular approaches. GhSINAT5 is expressed in several tissues of cotton plants, including roots, stems, leaves and cotyledons, and its expression levels are significantly affected by polyethylene glycol, abscisic acid and sodium chloride. When GhSINAT5 was silenced in cotton plants, drought and salinity stress occurred, and the length, area and volume of the roots significantly decreased. Under drought stress, the levels of proline, superoxide dismutase, peroxidase and catalase in the GhSINAT5-silenced cotton plants were significantly lower than those in the non-silenced control plants, whereas the levels of hydrogen peroxide and malondialdehyde were greater. Moreover, the expression of stress-related genes in silenced plants under drought stress suggested that GhSINAT5 may play a positive role in the plant response to drought and salt stress by regulating these stress response-related genes. These findings not only deepen our understanding of the mechanisms of drought resistance in cotton but also provide potential targets for future improvements in crop stress resistance through genetic engineering. [ABSTRACT FROM AUTHOR]

Cotton is essential for the textile industry as a primary source of natural fibers. However, environmental factors like drought present significant challenges to its cultivation, adversely affecting both production levels and fiber quality. Enhancing cotton's drought resilience has the potential to reduce yield losses and support the growth of cotton farming. In this study, the cotton calcium-dependent protein kinase GhCDPK16 was characterized, and the transcription level of GhCDPK16 was significantly upregulated under drought and various stress-related hormone treatments. Physiological analyses revealed that the overexpression of GhCDPK16 improved drought stress resistance in Arabidopsis by enhancing osmotic adjustment capacity and boosting antioxidant enzyme activities. In contrast, silencing GhCDPK16 in cotton resulted in increased dehydration compared with the control. Furthermore, reduced antioxidant enzyme activities and downregulation of ABA-related genes were observed in GhCDPK16-silenced plants. These findings not only enhanced our understanding of the biological functions of GhCDPK16 and the mechanisms underlying drought stress resistance but also underscored the considerable potential of GhCDPK16 in improving drought resilience in cotton. [ABSTRACT FROM AUTHOR]

Legumes are important grains and forages, providing high-quality proteins, vitamins, and micronutrients to humans and animals. Medicago truncatula is a close relative of alfalfa (Medicago sativa). Caffeic acid O-methyltransferase (COMT), a key gene that is identified to be essential for melatonin synthesis, plays a significant role in plant growth, development, and abiotic stress responses. However, a systematic study on the COMT gene family in M. truncatula has still not been reported. In this study, 63 MtCOMT genes were identified and categorized into three groups. Gene structure and conserved motif analyses revealed the relative conservation of closely clustered MtCOMTs within each group. Duplicated events in MtCOMT members were identified, and segmental duplication was the main mean. Cis-acting element prediction revealed the involvement of MtCOMTs in growth and development and response to light, stress, and plant hormones. RNA-seq data analysis showed that 57 MtCOMTs varied under salt and drought stresses. The RT-qPCR expression patterns showed that MtCOMT9, MtCOMT13, MtCOMT22, MtCOMT24, MtCOMT43, and MtCOMT46 were related to salt and drought responses in M. truncatula. Additionally, Arabidopsis thaliana overexpressing MtCOMT13 displayed superior plant growth phenotypes and enhanced tolerance to salt and drought stresses through higher photosynthetic parameters and activities of antioxidant enzymes, which indicated that MtCOMT13 played an important role in positively regulating plant salt and drought tolerance. These findings contribute to an improved understanding of MtCOMTs' roles in abiotic stress responses in M. truncatula, providing an important theoretical basis and genetic resource for legume species resistance breeding in the future. [ABSTRACT FROM AUTHOR]

The acceleration of the climate crisis and increased demand for water have caused water stress in many agricultural lands worldwide. This issue is of utmost importance as water stress represents one of the most crucial challenges for the agricultural sector and food security, affecting the growth and yield of crops. Developing agricultural strategies to mitigate the adverse effects of water stress and improve crop stress tolerance and crop yield is therefore crucial. This review aimed to analyze the effect of agricultural practices such as elicitation and biostimulation on mitigating the effects of water stress in vegetables. This manuscript provides relevant and recent information about the studied effects on various vegetable species and their responses under water deficit and agricultural and non-agricultural strategies to mitigate water stress, highlighting the use of elicitors and biostimulants. Inclusion criteria were scientific reports and book chapters published from 2000 to 2024, including keywords as follows: water stress + vegetables, water deficit + effects, drought stress management, agricultural strategies for water stress management, eustressors + water stress, elicitors and biostimulants + water stress mitigation. According to the reported literature, it was found that the physiological, biochemical, and molecular responses of vegetables to water stress depended on factors such as the severity and duration of the water deficit, the plant species, and the phenological state of the plants. Traditional agronomic strategies such as tillage, mulching, and intercropping for crop drought management were evaluated. Recently, alternative strategies for mitigating the effects of water stress have gained significant interest, such as the exogenous application of phytohormones and osmoprotectants, nutrient management, and the use of UV-B light, radiation, and acoustic waves, among others, whose eustressive effects (as biostimulants and elicitors) have been demonstrated. Among these eustressors, those of physical origin show great potential for mitigating water stress. To improve the individual potential of eustressors for water stress mitigation, we proposed the combination of practices such as tillage, mulching, application of hormones and osmoprotectants, and physical elicitors and biostimulants such as gamma rays, He-Ne laser, and UV-B. Further exploration is required to establish doses, application conditions, and effects on water stress mitigation and vegetable yield, underscoring the importance and ongoing nature of this research. [ABSTRACT FROM AUTHOR]

The continuous and reliable assessment of crop water status through water indicators enables the sustainable management of water resources, especially in arid or semi-arid climate scenarios exacerbated by climate change. Therefore, the main objective of this study is to determine and compare the sensitivity of indices derived from trunk diameter fluctuations for the accurate and automatic detection of changes in the water status of cherry trees. The water stress indicators examined are maximum daily trunk shrinkage (MDS), trunk growth rate (TGR), early daily trunk shrinkage (EDS), and late daily trunk shrinkage (LDS). During two growing seasons, 'Lapins' sweet cherry trees were subjected to different water stress levels: (i) a control treatment irrigated at 115% of crop evapotranspiration demand to ensure non-limiting water conditions, and (ii) a deficit irrigation treatment, with two irrigation withholding cycles. Vegetative growth was affected by water stress. Trunk daily growth rate and late daily trunk shrinkage exhibited a high variability and did not clearly show differences in plant water status. Both EDS and MDS showed a third-degree polynomial relationship with Ψstem. MDS had a lineal relationship with Ψstem of up to −1.4 MPa; however, further decreases in Ψstem did not necessarily lead to increased MDS. In contrast, EDS became non-linear at −1.8 MPa, making it a more useful plant water indicator than MDS for 'Lapins' sweet cherry trees when detecting severe water stress conditions. The frequencies of both MDS and EDS decreased from 85% to 35% when water stress increased. Therefore, the information provided by MDS and EDS frequencies, along with their daily values, could be useful as irrigation management tools for sweet cherry trees. [ABSTRACT FROM AUTHOR]

Simple Summary: Given that drought stress may particularly threaten plant survival and crop yields, plants have developed sophisticated adaptive strategies including drought tolerance, escape, and avoidance strategies, for dealing with drought stress. Abscisic acid has been widely acknowledged as a principal signaling molecule in plants responding to drought, reducing water loss by prompting stomatal closure while activating various stress-responsive genes. Broad-complex, Tramtrack, and Bric-à-brac (BTB) proteins in plants are important for plant growth and stress responses. The Arabidopsis btb-a2.1/2/3 mutant confers drought tolerance by modulating plant growth parameters, physiology, and gene expression. Overall, AtBTB-A2s negatively regulate drought tolerance by suppressing stomatal closure and weakening ABA signaling. The results revealed the new physiological activity of AtBTB-A2s within Arabidopsis and the possible mechanism that mediates ABA-dependent signaling pathways during drought stress. Drought stress significantly impacts plant growth, productivity, and yield, necessitating a swift fine-tuning of pathways for adaptation to harsh environmental conditions. This study explored the effects of Arabidopsis BTB-A2.1, BTB-A2.2, and BTB-A2.3, distinguished by their exclusive possession of the Broad-complex, Tramtrack, and Bric-à-brac (BTB) domain, on the negative regulation of drought stress mediated by abscisic acid (ABA) signaling. Promoter analysis revealed the presence of numerous ABA-responsive and drought stress-related cis-acting elements within the promoters of AtBTB-A2.1, AtBTB-A2.2, and AtBTB-A2.3. The AtBTB-A2.1, AtBTB-A2.2, and AtBTB-A2.3 transcript abundances increased under drought and ABA induction according to qRT-PCR and GUS staining. Furthermore, the Arabidopsis btb-a2.1/2/3 triple mutant exhibited enhanced drought tolerance, supporting the findings from the overexpression studies. Additionally, we detected a decrease in the stomatal aperture and water loss rate of the Arabidopsis btb-a2.1/2/3 mutant, suggesting the involvement of these genes in repressing stomatal closure. Importantly, the ABA signaling-responsive gene levels within Arabidopsis btb-a2.1/2/3 significantly increased compared with those in the wild type (WT) under drought stress. Based on such findings, Arabidopsis BTB-A2s negatively regulate drought stress via the ABA signaling pathway. [ABSTRACT FROM AUTHOR]

This study aimed to elucidate responses of the bacterial structure and diversity of the rhizosphere in flowering broomcorn millet after rehydration following drought stress. In this study, the broomcorn millet varieties 'Hequ red millet' (A1) and 'Yanshu No.10′ (A2), known for their different drought tolerance levels, were selected as experimental materials. The plants were subjected to rehydration after drought stress at the flowering stage, while normal watering (A1CK and A2CK) served as the control. Soil samples were collected at 10 days (A11, A21, A1CK1, and A2CK1) and 20 days (A12, A22, A1CK2, and A2CK2) after rehydration. High-throughput sequencing technology was employed to investigate the variations in bacterial community structure, diversity, and metabolic functions in the rhizosphere of the broomcorn millet at different time points following rehydration. The findings indicated that the operational taxonomic units (OTUs) of bacteria in the rhizosphere of broomcorn millet were notably influenced by the duration of treatment, with a significant decrease in OTUs observed after 20 days of rehydration. However, bacterial Alpha diversity was not significantly impacted by rehydration following drought stress. The bacterial community in the rhizosphere of broomcorn millet was mainly composed of Actinobacteria and Proteobacteria. After rewatering for 10 to 20 days after drought stress, the abundance of Sphingomonas and Aeromicrobium in the rhizosphere soil of the two varieties of broomcorn millet decreased gradually. Compared with Yanshu No.10, the abundance of Pseudarthrobacter in the rhizosphere of Hequ red millet gradually increased. A Beta diversity analysis revealed variations in the dissimilarities of the bacterial community which corresponded to different rehydration durations. The relative abundance of bacterial metabolic functions in the rhizosphere of broomcorn millet was lower after 20 days of rehydration, compared to measurements after 10 days of rehydration. This observation might be attributed to the exchange of materials between broomcorn millet and microorganisms during the initial rehydration stage to repair the effects of drought, as well as to the enrichment of numerous microorganisms to sustain the stability of the community structure. This study helps to comprehend the alterations to the bacterial structure and diversity in the rhizosphere of broomcorn millet following drought stress and rehydration. It sheds light on the growth status of broomcorn millet and its rhizosphere microorganisms under real environmental influences, thereby enhancing research on the drought tolerance mechanisms of broomcorn millet. [ABSTRACT FROM AUTHOR]

Maize, a vital cereal in global agriculture, faces significant yield challenges due to drought exacerbated by climate change. This study explores the genetic and molecular bases of drought resilience in maize, focusing on the EPF/EPFL gene family known for its role in stomatal regulation. Through a genome-wide analysis across seven grass species, we identified and characterized 16 ZmEPF/EPFL genes in maize. Focusing on their gene structure, expression patterns, and evolutionary relationships. The study integrated genome-wide searches, phylogenetic analysis, gene expression profiling under drought and other abiotic stresses, and qRT-PCR validation to elucidate the functional roles of these genes in drought response. Our results demonstrate that specific ZmEPF/EPFL genes are differentially expressed under varying drought conditions, suggesting their involvement in the plant's adaptive response to water scarcity. Furthermore, interaction analyses reveal that these genes are linked to key processes such as stomatal development and oxidative stress management. This study provides a comprehensive overview of the ZmEPF/EPFL gene family's contribution to stomatal development and drought tolerance, offering insights that could guide future breeding strategies for drought-resistant maize varieties. [ABSTRACT FROM AUTHOR]

Drought stress is one of the main factors affecting the growth and secondary metabolism of plants. Iris domestica, rich in isoflavones, is a common herbal medicine in China. In this study, the effects of drought stress and rehydration on resistance physiological characteristics and the secondary metabolism of two-year-old I. domestica during the vegetative and reproductive growth period were investigated. The results showed that the dry weight and fresh weight of rhizomes and roots under severe drought stress were significantly decreased, while those under moderate drought stress were not significantly changed. Meanwhile, the SOD activities, POD activities, MDA content and Pro content increased to resist drought at D1 and D2. In the vegetative growth period, the changes in isoflavone concentration and the expression levels of genes in isoflavone synthesis were more dramatic. Isoflavone accumulation was promoted, to some extent, in the reproductive growth period under the D1 drought treatment. In the actual production process, different measures, namely short-term stress regulation in the vegetative growth period and moderate drought stress (13.44% < soil water content ≤ 16.8%) in the reproductive growth period, need to be adopted to regulate isoflavone biosynthesis. [ABSTRACT FROM AUTHOR]

Background: Opuntia ficus-indica (L.) Miller is dominantly growing on degraded soils in arid and semi-arid areas. The plants might establish a strong association with arbuscular mycorrhizal fungi (AMF) to adapt to nutrient, drought, and herbivore insect stress. The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels (SWA) on the biomass, nutrient concentration, nutritional composition, and nutrient digestibility of the spiny and spineless O. ficus-indica by inducing resistance to cochineal stress. One mother Opuntia ficus-indica cladode was planted in a single pot in each field with 24 kg mixed soil. AMF inoculums were cultured in sorghum plants in a greenhouse and were inoculated in the planted cladodes. The planted cladodes were arranged using a completely randomized design (CRD) with three factors: AMF (present and absent); O. ficus-indica type (spiny and spineless) and four water treatments with 0–25% of plant available soil water (SWA), 25–50% of SWA, 50–75% of SWA, and 75–100% of SWA. Results: Drought stress reduced the below and above-ground biomass, cladode nutrient content, nutritional composition, and in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD). AMF colonization significantly increased biomass production with significant changes in the macro and micro-nutrient concentrations of O. ficus-indica. AMF inoculation significantly increased the IVDMD and IVOMD of both O. ficus-indica types by improving the biomass, organic matter (OM), crude protein (CP), and reduced fiber and ash contents. AMF-inoculated cladodes improved the nutrient concentrations of the cladodes. AMF caused an increase in biomass production, increased tolerance to cochineal stress, and improved nutrient concentration, nutritional composition, and nutrient digestibility performance of O. ficus-indica plants. Conclusions: AMF improved the performance of the O. ficus-indica plant to resist drought and cochineal stress and increased the biomass, nutrient concentration, nutritional composition, and nutrient digestibility. The potential of O. ficus-indica to adapt to cochineal stress is controlled by the macro and micro-nutrient concentration brought by the AMF association. [ABSTRACT FROM AUTHOR]

Water is an important constraint on alfalfa (Medicago sativa) production in arid and semiarid areas, and alternate irrigation in root areas has water-saving potential for alfalfa production. To investigate the impact of alternate partial root-zone irrigation (APRI) on the rhizosphere soil microorganisms of alfalfa, this study subjected alfalfa plants to different irrigation methods and irrigation levels. The growth status and rhizosphere soil microbial community diversity of alfalfa plants under alternate root-zone watering treatment were analyzed through laboratory experiments and high-throughput sequencing. The results showed that at soil moisture levels of 80% field moisture capacity (FMC) and 60% FMC, APRI had no significant impact on the biomass or nodule number of alfalfa. However, 40% FMC significantly reduced the individual plant dry weight, chlorophyll content, and nodule number of the alfalfa plants. APRI increased the relative abundance of Actinomycetes in the alfalfa rhizosphere soil. Moreover, at 60% FMC, the MBC and MBN of rhizosphere, relative abundance of Actinobacteria and unclassified K fungi and Chao 1 index of bacteria significantly increased under APRI treatment. While relative abundance of Ascomycetes and Proteobacteria in the alfalfa rhizosphere significantly reduced under 60% FMC + APRI treatment. In summary, under the same irrigation conditions, APRI did not significantly affect the growth of alfalfa in the short term. And 60%FMC + APRI treatment did significantly affect the groups, structure and diversity of the rhizosphere soil microbial communities. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging has emerged as a pivotal technology in agricultural research, offering a powerful means to non-invasively monitor stress factors, such as drought, in crops like potato plants. In this context, the integration of attention-based deep learning models presents a promising avenue for enhancing the efficiency of stress detection, by enabling the identification of meaningful spectral channels. This study assesses the performance of deep learning models on two potato plant cultivars exposed to water-deficient conditions. It explores how various sampling strategies and biases impact the classification metrics by using a dual-sensor hyperspectral imaging systems (VNIR -Visible and Near-Infrared and SWIR—Short-Wave Infrared). Moreover, it focuses on pinpointing crucial wavelengths within the concatenated images indicative of water-deficient conditions. The proposed deep learning model yields encouraging results. In the context of binary classification, it achieved an area under the receiver operating characteristic curve (AUC-ROC—Area Under the Receiver Operating Characteristic Curve) of 0.74 (95% CI: 0.70, 0.78) and 0.64 (95% CI: 0.56, 0.69) for the KIS Krka and KIS Savinja varieties, respectively. Moreover, the corresponding F1 scores were 0.67 (95% CI: 0.64, 0.71) and 0.63 (95% CI: 0.56, 0.68). An evaluation of the performance of the datasets with deliberately introduced biases consistently demonstrated superior results in comparison to their non-biased equivalents. Notably, the ROC-AUC values exhibited significant improvements, registering a maximum increase of 10.8% for KIS Krka and 18.9% for KIS Savinja. The wavelengths of greatest significance were observed in the ranges of 475–580 nm, 660–730 nm, 940–970 nm, 1420–1510 nm, 1875–2040 nm, and 2350–2480 nm. These findings suggest that discerning between the two treatments is attainable, despite the absence of prominently manifested symptoms of drought stress in either cultivar through visual observation. The research outcomes carry significant implications for both precision agriculture and potato breeding. In precision agriculture, precise water monitoring enhances resource allocation, irrigation, yield, and loss prevention. Hyperspectral imaging holds potential to expedite drought-tolerant cultivar selection, thereby streamlining breeding for resilient potatoes adaptable to shifting climates. [ABSTRACT FROM AUTHOR]

Drought stress, which is becoming more prevalent due to climate change, is a significant abiotic factor that adversely impacts crop production and yield stability. Cultivated soybean (Glycine max), a versatile crop for humans and animals, exhibits sensitivity to drought, resulting in reduced growth and development under drought conditions. However, few genetic studies have assessed wild soybean's (Glycine soja) response to drought stress. In this work, we conducted a genome-wide association study (GWAS) and analysis of wild soybean accessions to identify loci responsible for drought tolerance at the vegetative (n = 187) and the germination stages (n = 135) using the available resequencing data. The GWAS analysis of the leaf wilting score (LWS) identified eight single-nucleotide polymorphisms (SNPs) on chromosomes 10, 11, and 19. Of these, wild soybeans with both SNPs on chromosomes 10 (adenine) and 11 (thymine) produced lower LWS, indicating that these SNPs have an important role in the genetic effect on LWS for drought tolerance at the vegetative stage. At the germination stage, nine SNPs associated with five phenotypic measurements were identified on chromosomes 6, 9, 10, 13, 16, and 17, and the genomic regions identified at the germination stage were different from those identified for the LWS, supporting our previous finding that there may not be a robust correlation between the genes influencing phenotypes at the germination and vegetative stages. This research will benefit marker-assisted breeding programs aimed at enhancing drought tolerance in soybeans. [ABSTRACT FROM AUTHOR]

Apple is an important horticultural crop, but various adverse environmental factors can threaten the quality and yield of its fruits. The ability of apples to resist stress mainly depends on the rootstock. Malus baccata (L.) Borkh. is a commonly used rootstock in Northeast China. In this study, it was used as the experimental material, and the target gene MbWRKY53 was screened through transcriptome analysis and Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) after cold and drought treatment. Bioinformatics analysis revealed that this transcription factor (TF) belonged to the WRKY TF family, and its encoded protein was localized in the nucleus. RT-qPCR showed that the gene was more easily expressed in roots and young leaves and is more responsive to cold and drought stimuli. Functional validation in Arabidopsis thaliana confirmed that MbWRKY53 can enhance plant tolerance to cold and drought stress. Furthermore, by analyzing the expression levels of genes related to cold and drought stress in transgenic Arabidopsis lines, it was inferred that this gene can regulate the expression of stress-related genes through multiple pathways such as the CBF pathway, SOS pathway, Pro synthesis pathway, and ABA-dependent pathways, enhancing the adaptability of transgenic Arabidopsis to cold and drought environments. [ABSTRACT FROM AUTHOR]

Drought is a major factor affecting crops, thus efforts are needed to increase plant resilience to this abiotic stress. The overlapping signaling pathways between drought and cell wall integrity maintenance responses create a possibility of increasing drought resistance by modifying cell walls. Here, using herbaceous and woody plant model species, Arabidopsis and hybrid aspen, respectively, we investigated how the integrity of xylan in secondary walls affects the responses of plants to drought stress. Plants, in which secondary wall xylan integrity was reduced by expressing fungal GH10 and GH11 xylanases or by affecting genes involved in xylan backbone biosynthesis, were subjected to controlled drought while their physiological responses were continuously monitored by RGB, fluorescence, and/or hyperspectral cameras. For Arabidopsis, this was supplemented with survival test after complete water withdrawal and analyses of stomatal function and stem conductivity. All Arabidopsis xylan-impaired lines showed better survival upon complete watering withdrawal, increased stomatal density and delayed growth inhibition by moderate drought, indicating increased resilience to moderate drought associated with modified xylan integrity. Subtle differences were recorded between xylan biosynthesis mutants (irx9, irx10 and irx14) and xylanaseexpressing lines. irx14 was the most drought resistant genotype, and the only genotype with increased lignin content and unaltered xylem conductivity despite its irx phenotype. Rosette growth was more affected by drought in GH11- than in GH10-expressing plants. In aspen, mild downregulation of GT43B and C genes did not affect drought responses and the transgenic plants grew better than the wild-type in drought and well-watered conditions. Both GH10 and GH11 xylanases strongly inhibited stem elongation and root growth in well-watered conditions but growth was less inhibited by drought in GH11-expressing plants than in wild-type. Overall, plants with xylan integrity impairment in secondary walls were less affected than wild-type by moderately reduced water availability but their responses also varied among genotypes and species. Thus, modifying the secondary cell wall integrity can be considered as a potential strategy for developing crops better suited to withstand water scarcity, but more research is needed to address the underlying molecular causes of this variability. [ABSTRACT FROM AUTHOR]

Leaf mustard (Brassica juncea L. Czern & Coss), an important vegetable crop, experiences pronounced adversity due to seasonal drought stress, particularly at the seed germination stage. Although there is partial comprehension of drought-responsive genes, the role of long non-coding RNAs (lncRNAs) in adjusting mustard's drought stress response is largely unexplored. In this study, we showed that the drought-tolerant cultivar 'Weiliang' manifested a markedly lower base water potential (−1.073 MPa vs −0.437 MPa) and higher germination percentage (41.2% vs 0%) than the drought-susceptible cultivar 'Shuidong' under drought conditions. High throughput RNA sequencing techniques revealed a significant repertoire of lncRNAs from both cultivars during germination under drought stress, resulting in the identification of 2,087 differentially expressed lncRNAs (DELs) and their correspondingly linked 12,433 target genes. It was noted that 84 genes targeted by DEL exhibited enrichment in the photosynthesis pathway. Gene network construction showed that MSTRG.150397, a regulatory lncRNA, was inferred to potentially modulate key photosynthetic genes (Psb27, PetC, PetH, and PsbW), whilst MSTRG.107159 was indicated as an inhibitory regulator of six drought-responsive PIP genes. Further, weighted gene co-expression network analysis (WGCNA) corroborated the involvement of light intensity and stress response genes targeted by the identified DELs. The precision and regulatory impact of lncRNA were verified through qPCR. This study extends our knowledge of the regulatory mechanisms governing drought stress responses in mustard, which will help strategies to augment drought tolerance in this crop. [ABSTRACT FROM AUTHOR]

The impact of biochar application on plant performance under drought stress necessitates a comprehensive understanding of biochar–soil interaction, root growth, and plant physiological processes. Therefore, pot experiments were conducted to assess the effects of biochar on plant responses to drought stress at the seedling stage. Two contrasting maize genotypes (drought-sensitive KN5585 vs. -tolerant Mo17) were subjected to biochar application under drought stress conditions. The results indicated that biochar application decreased soil exchangeable Na+ and Ca2+ contents while increased soil exchangeable K+ content (2.7-fold) and electrical conductivity (4.0-fold), resulting in an elevated leaf sap K+ concentration in both maize genotypes. The elevated K+ concentration with biochar application increased root apoplastic pH in the drought-sensitive KN5585, but not in the drought-tolerant Mo17, which stimulated the activation of H+-ATPase and H+ efflux in KN5585 roots. Apoplast alkalinization of the drought-sensitive KN5585 resulting from biochar application further inhibited root growth by 30.7%, contributing to an improvement in water potential, a reduction in levels of O2–, H2O2, T-AOC, SOD, and POD, as well as the down-regulation of genes associated with drought resistance in KN5585 roots. In contrast, biochar application increased leaf sap osmolality and provided osmotic protection for the drought-tolerant Mo17, which was associated with trehalose accumulation in Mo17 roots. Biochar application improved sucrose utilization and circadian rhythm of Mo17 roots, and increased fresh weight under drought stress. This study suggests that biochar application has the potential to enhance plant drought tolerance, which is achieved through the inhibition of root growth in sensitive plants and the enhancement of osmotic protection in tolerant plants, respectively. Biochar application decreased soil exchangeable Na+ and Ca2+, but increased soil exchangeable K+ and electrical conductivity. Biochar increased apoplastic pH, but reduced root growth, stress damage and stress response during drought for the drought-sensitive KN5585. Biochar improved osmotic protection, trehalose accumulation, and fresh weight during drought for the drought-tolerant Mo17. [ABSTRACT FROM AUTHOR]

S. scabra is an important forage and extremophilic plant native to the Brazilian Caatinga semiarid region. It has only recently been subjected to omics-based investigations, and the generated datasets offer insights into biotechnologically significant candidates yet to be thoroughly examined. INSs (inositol and its derivatives) and RFO (raffinose oligosaccharide family) pathways emerge as pivotal candidates, given their critical roles in plant physiology. The mentioned compounds have also been linked to negative impacts on the absorption of nutrients in mammals, affecting overall nutritional intake and metabolism. Therefore, studying these metabolic pathways is important not just for plants but also for animals who depend on them as part of their diet. INS and RFO pathways in S. scabra stood out for their abundance of identified loci and enzymes. The enzymes exhibited genomic redundancy, being encoded by multiple loci and various gene families. The phylogenomic analysis unveiled an expansion of the PIP5K and GolS gene families relative to the immediate S. scabra ancestor. These enzymes are crucial for synthesizing key secondary messengers and the RFO precursor, respectively. Transcriptional control of the studied pathways was associated with DOF-type, C2H2, and BCP1 transcription factors. Identification of biological processes related to INS and RFO metabolic routes in S. scabra highlighted their significance in responding to stressful conditions prevalent in the Caatinga environment. Finally, RNA-Seq and qPCR data revealed the relevant influence of genes of the INS and RFO pathways in the S. scabra response to water deprivation. Our study deciphers the genetics and transcriptomics of the INS and RFO in S. scabra, shedding light on their importance for a Caatinga-native plant and paving the way for future biotechnological applications in this species and beyond. [ABSTRACT FROM AUTHOR]