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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]

Key message: The barley mutant xan-h.chli-1 shows phenotypic features, such as reduced leaf chlorophyll content and daily transpiration rate, typical of wild barley accessions and landraces adapted to arid climatic conditions. The pale green trait, i.e. reduced chlorophyll content, has been shown to increase the efficiency of photosynthesis and biomass accumulation when photosynthetic microorganisms and tobacco plants are cultivated at high densities. Here, we assess the effects of reducing leaf chlorophyll content in barley by altering the chlorophyll biosynthesis pathway (CBP). To this end, we have isolated and characterised the pale green barley mutant xan-h.chli-1, which carries a missense mutation in the Xan-h gene for subunit I of Mg-chelatase (HvCHLI), the first enzyme in the CBP. Intriguingly, xan-h.chli-1 is the only known viable homozygous mutant at the Xan-h locus in barley. The Arg298Lys amino-acid substitution in the ATP-binding cleft causes a slight decrease in HvCHLI protein abundance and a marked reduction in Mg-chelatase activity. Under controlled growth conditions, mutant plants display reduced accumulation of antenna and photosystem core subunits, together with reduced photosystem II yield relative to wild-type under moderate illumination, and consistently higher than wild-type levels at high light intensities. Moreover, the reduced content of leaf chlorophyll is associated with a stable reduction in daily transpiration rate, and slight decreases in total biomass accumulation and water-use efficiency, reminiscent of phenotypic features of wild barley accessions and landraces that thrive under arid climatic conditions. [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]

Today, when desertification is one of the expected ecological disasters in the background of global climate change, investigation of the biological mechanisms of xerophytes stress resistance has become popular. One of the key biochemical mechanisms of plant protection against unfavourable environmental conditions is a large group of compounds with different chemical nature united under the name of antioxidant system. Investigation of the characteristics of the antioxidant system of xerophytes of different habitats of the driest region of Georgia (East Georgia) was the aim of the presented study. The content of low-molecular antioxidants and osmolytes as well as the activity of antioxidant enzymes was studied in leaves of experimental plants. It has been concluded that the distinctive values of the indices of antioxidant system are manifested as the main mechanism of adaptation. There can be several such mechanisms in each species at the same time, which is probably a specific feature. In some cases, these mechanisms are similar in species of one habitat and presumably are related to the living environment; In general, it is possible to single out characteristic strategy of adaptation to stress for each studied species, which includes certain enzymatic and non-enzymatic components of the antioxidant system. [ABSTRACT FROM AUTHOR]

Integrating grain yield, component traits and metabolite profiles aids in selecting drought‐adapted and climate‐smart crop varieties preferred by end users. Understanding the trends and magnitude of grain‐based metabolites is vital for selecting wheat genotypes with higher grain yield, drought tolerance, water use efficiency and product profiles. The aim of this study was to determine the response of newly developed wheat genotypes for grain yield and component traits and metabolites under drought stress to guide selection. One hundred wheat genotypes were preliminarily evaluated for agro‐morphological traits and water use efficiency under drought‐stressed and non‐stressed conditions during the 2022 and 2023 growing seasons using a 5 × 20 alpha lattice design with two replications. Ten high‐yielding genotypes were selected based on grain yield and were validated for agronomic traits and water use efficiency (WUE), and grain samples were assayed to profile their key metabolites under drought‐stressed conditions. Significant differences existed (p < 0.05) among the tested wheat genotypes for yield and yield components, WUE, drought tolerance and major metabolites to discern trait associations. The grain yield of the 10 genotypes ranged from 590.00 g m−2 (genotype LM70 × BW140) to 800.00 g m−2 (BW141 × LM71) under drought‐stressed treatment, whilst under non‐stressed it ranged from 760.06 g m −2 (LM70 × BW140) to 908.33 g m−2 (LM71 × BW162). Grain yield‐based water use efficiency of the assessed genotypes was higher under non‐stressed (0.18 g mm−1) than drought‐stressed (0.17 g mm−1) conditions. The highest drought tolerance index (211.67) and stress susceptibility index (0.77) were recorded for BW162 × LM71, whilst the lowest tolerance index (23.33) and stress susceptibility index (0.09) were recorded in BW141 × LM71. Grain metabolites, including the apigenin‐8‐C‐glucoside (log2Fold = 3.00) and malate (log2Fold = 3.60) were present in higher proportions in the high‐yielding genotypes (BW141 × LM71 and LM71 × BW162) under drought‐stressed conditions, whilst fructose (log2Fold = −0.50) and cellulose (log2Fold = −3.90) showed marked decline in the two genotypes. Based on phenotypic and metabolite profile analyses, genotypes BW141 × LM71 and LM71 × BW162 were selected for being drought‐tolerant, water‐use efficient and recommended for production or breeding. The findings revealed associations between yield components, water use efficiency and grain metabolites to guide the selection of best‐performing and drought‐tolerant wheat varieties. [ABSTRACT FROM AUTHOR]

In regions of South Asia where rainfed maize is grown, effective crop management during drought is essential for maximising yield. A variety of water‐conserving planting practices are used, and more recently, techniques such as foliar supplementation to maintain nutrients during drought have also shown promise. However, specific combinations of these approaches are often untested for optimality. Here, we explore the effects of two maize planting practices (ridge sowing and mulching) to conserve water, in combination with foliar thiourea. Drought stress response of crop was assessed at two experimental sites (L‐I and L‐II), through split‐plot design (main plots: flat sowing + mulch, flat sowing, ridge sowing + mulch [RS + M] and ridge sowing; sub‐plots: unsprayed, water spray, 500 ppm thiourea and 1000 ppm thiourea). Plant performance was assessed via dry matter accumulation, grain growth rate, stomatal parameters, grain yield, stover yield and nitrogen uptake. Rainfall breaks induced three dry spells during the pre‐anthesis and grain‐filling period. RS + M showed maximum drought tolerance by enhancing rainwater and nutrient use (N uptake [88.1 and 115.1 kg ha−1]) and recorded significantly higher periodic dry matter accumulation (149.2 and 156.8 g) along with higher 1000‐grain weight (181.0 and 196.6 g), grain‐filling duration (36.3 and 34.9 days) and leaf health parameters over the flat‐sown treatments. Furthermore, foliar supplementation of thiourea at 1000 ppm caused improved leaf health, likely through activation of a source to sink response (transfer of energy and materials from leaves to other plant organs) that alleviated moisture stress. Ultimately, the combination of RS + M and 1000 ppm thiourea led to the highest grain yields (32.1 and 39.5 qha−1). [ABSTRACT FROM AUTHOR]

Drought stress significantly challenges wheat production globally, and drought priming has emerged as an effective strategy to mitigate yield loss under drought stress events. However, the effect of drought priming on plant nitrogen use efficiency (NUE) remains insufficiently understood. This study investigates the effects of drought priming at the six‐leaf stage on NUE under drought stress during grain filling in four wheat varieties with distinct responses to drought priming. Our results indicate that there is no correlation between inherent drought tolerance and the effects of drought priming among the wheat varieties studied. In priming‐sensitive varieties, drought‐primed plants exhibited significant improvements in grain yield and NUE under drought stress compared to non‐primed plants. Conversely, priming‐insensitive varieties showed no significant differences in yield or NUE between primed and non‐primed plants under similar conditions. Notably, under drought stress, primed plants exhibited higher yield and NUE than non‐primed plants in drought priming positive variety, while the opposite trend was observed in drought priming negative response variety. The enhancement of NUE through drought priming was associated with improved nitrogen uptake efficiency and its allocation to spikes, with abscisic acid accumulation playing a pivotal role. These findings provide valuable insights into the mechanisms by which drought priming enhances NUE under drought stress, contributing to the development of sustainable agricultural practices amid climate change. [ABSTRACT FROM AUTHOR]

The responses of eco‐physiological processes such as leaf expansion, plant transpiration and senescence to soil water deficit have been reported to be genotype‐dependent in different crops. To study such responses in soybean (Glycine max. (L.) Merr.), a 2‐year (2017 and 2021) outdoor pot experiment was carried out on the Heliaphen automated phenotyping platform at INRAE in Toulouse (France). Six soybean cultivars (Sultana‐MG 000, ES Pallador‐MG I, Isidor‐MG I, Santana‐MG I/II, Blancas‐MG II and Ecudor‐MG II) belonging to four maturity groups (MG) commonly grown in Europe were subjected to progressive soil water deficit from the reproductive stage R1 for 17 and 23 days in 2017 and 2021, respectively. The fraction of transpirable soil water (FTSW) was used as an indicator of soil water deficit. Non‐linear regression was used to calculate FTSWt, that is, the FTSW threshold for which the rate of the eco‐physiological process in stressed plants starts to diverge from a reference value. According to FTSWt, the three eco‐physiological processes showed significant differences in sensitivity to water deficit: leaf expansion exhibits the highest sensitivity and the widest range (FTSWt: 0.44–0.93), followed by plant transpiration (FTSWt: 0.17–0.56), with leaf senescence showing the narrowest range (FTSWt: 0.05–0.16). Among six cultivars, regarding leaf expansion, Cvs Santana (FTSWt = 0.48 in 2017; FTSWt = 0.44 in 2021), Blancas (FTSWt = 0.51 in 2017; FTSWt = 0.48 in 2021) and Ecudor (FTSWt = 0.46 in 2017; FTSWt = 0.52 in 2021) in late MGs (I/II to II) exhibited higher tolerance to soil drying. Conversely, the cv. Sultana in the earliest MG (000) showed the highest sensitivity (FTSWt = 0.91 in 2017; FTSWt = 0.93 in 2021) to water deficit. However, concerning the FTSWt values for plant transpiration (0.17–0.56 in 2017; 0.19–0.31 in 2021) and senescence (0.05–0.16 in 2017; 0.06–0.16 in 2021), their range did not demonstrate a correlated trend with the MG. In addition, a negative linear correlation was observed between values of FTSWt of normalised leaf expansion at the whole‐plant level (NLE) and specific leaf area (SLA) measured on irrigated plants for both years. This suggests that genotypes with high values of SLA could be associated with higher tolerance of leaf expansion to soil water deficit. Such a non‐destructive phenotyping method under outdoor conditions could bring new information to variety testing process and provide paths for integrating genotypic variability into crop growth models used for simulating soybean eco‐physiological responses to water deficit across the plant, field and even regional scales. [ABSTRACT FROM AUTHOR]

Identifying the genomic regions (quantitative trait loci (QTL)) significantly linked to grain yield under drought stress could expedite the development of novel rice cultivars suited for rainfed areas through marker‐assisted breeding. This study identified QTL regions linked to plant phenology and production traits by evaluating 122 recombinant inbred lines (RILs) of Danteshwari × Daggaddeshi under different environmental conditions. A consistent QTL region associated with grain yield under water stress (60.4 Mbp) was mapped on chromosome 1 between RM428 and RM24 with an LOD score of 4.0. Another QTL region (9.4 Mbp) linked to plant height under all environmental conditions was mapped on chromosome 1 between RM1‐HvSSR1‐87 with a LOD score of 7.5 and phenotypic variance of 25%. A core set of 402 diverse rice accessions was also evaluated under water stress conditions and subjected to genome‐wide association analysis. Twelve markers linked to grain yield under drought were identified, out of which five were significantly associated with grain yield and days to flowering under drought. The markers linked to grain yield were compared between the bi‐parental population and germplasm accessions to identify the common markers. Three markers (RM1, RM259 and RM201) were found to be consistently linked to drought stress across the seasons in both bi‐parental population and germplasm accessions studied and could be potential candidates for application in marker‐assisted selection for improving grain yield under drought stress in rice. [ABSTRACT FROM AUTHOR]

In this study, a novel microwave sensing system, consisting of a microstrip self-resonant spiral coil inductively coupled to an external concentric planar probe loop, is presented and applied to the non-destructive detection of morpho-physiological plant responses to water stress. The optimised set-up of the proposed sensor ensures a highly sensitive spiral coil, which is a fundamental requirement to derive accurate information on plants' behavioural alterations related to water stress conditions. The proposed microwave sensor was tested it on two potted maize cultivars (Zea mays L.), namely " Cinquantino Bianchi " (CB) and " Scagliolo Frassine " (SF). For each cultivar, half of the samples were maintained at 100% (T100) field capacity while the other half was at 25% (T25) from 46 to 74 Days After Sowing (DAS). The frequency (f r) shift and the amplitude peaks variation of the real component of the external planar probe input impedance (ℜ(Z i n p u t )) were obtained daily by positioning the sensor on the stem. These measured data were related to morpho-physiological parameters destructively acquired at four different growth stages. The resulting linear correlation between the stem's freshwater content ( F W C s t e m ) with both f r (r > −0.64) and the amplitude peaks (ℜ (Z i n p u t )) (r > -0.70) provided evidence of the sensor's ability to identify stem dielectric properties' variations between the two water treatments. Concurrently, the sensor response demonstrated the capability to identify changes in the morphology and histology of the stem. Based on preliminary findings, the proposed sensor shows potential for employment in the real-time monitoring of plant water status, contributing to more economically and environmentally sustainable crop management practices. While the current correlations between plant water content and sensor measurements require further refinement to meet the rigorous industrial standards, nevertheless a large-scale adoption can be envisioned by leveraging IoT methodologies. • A novel sensor to non-destructively decode plant water stress responses is proposed. • Stress-induced resonance frequency and amplitude shifts in the stem signal recorded. • Stem dielectric properties were highly responsive to water content variations. • Variety-dependent adjustments of maize stem anatomy to water stress detected. • Sensor offers a valid solution for real-time monitoring of plant water needs. [ABSTRACT FROM AUTHOR]

Numerous abiotic and biotic stresses threaten sustainable agriculture under limited resources. Agriculture productivity is disrupted by these unpredictable environmental fluctuations, posing a serious threat to food security. As a beneficial nutrient, silicon (Si) application enhances biological functions, crop development and productivity. Silicon application has garnered attention for its ability to mitigate various stresses and has shown a highly significant response under conditions such as water scarcity, salinity, metal toxicity, thermal stress and nutrients deprivation. Additionally, it enhances defense mechanisms against fungal, bacterial and pest attacks. High crops production can be achieved by incorporating Si into the agricultural system to replace synthetic fertilizers. This approach can help overcome limitations in crop production posed by limited resources and unpredictable environmental conditions. The environmentally friendly Si application is replacement of synthetic toxic chemicals for sustainable agriculture to get maximum yield under limited resources and unpredictable environmental conditions, as well regulate the genes expression to mitigate the biotic and abiotic stresses. The keys genes involved in different metabolic pathways under Si application have discussed in this study, which will be more beneficial to develop stress resilient crops through CRISPR/CAS technology to overcome the food threat and agriculture sustainability. [ABSTRACT FROM AUTHOR]

This study aimed to explore the role of the trehalose-6-phosphate synthase (TPS) gene family in the adaptation of peas to environmental stress. A comprehensive analysis of the PsTPS gene family identified 20 genes with conserved domains and specific chromosomal locations. Phylogenetic analysis delineated evolutionary relationships, while gene structure analysis revealed compositional insights, and motif analysis provided functional insights. Cis-regulatory element identification predicted gene regulation patterns. Tissue-specific and stress-induced expression profiling highlighted eight genes with ubiquitous expression, with PsTPS15 and PsTPS18 displaying elevated expression levels in roots, nodules, and young stems, and PsTPS13 and PsTPS19 expression downregulated in seeds. Transcriptome analysis identified a differential expression of 20 PsTPS genes, highlighting the significance of 14 genes in response to drought and salinity stress. Notably, under drought conditions, the expression of PsTPS4 and PsTPS6 was initially upregulated and then downregulated, whereas that of PsTPS15 and PsTPS19 was downregulated. Salinity stress notably altered the expression of PsTPS4, PsTPS6, and PsTPS19. Taken together, these findings elucidate the regulatory mechanisms of the PsTPS gene family and their potential as genetic targets for enhancing crop stress tolerance. [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]

The MADS-box gene family constitutes a vital group of transcription factors that play significant roles in regulating plant growth, development, and signal transduction processes. However, research on the MADS-box genes in cassava (Manihot esculenta) has been relatively limited. To gain deeper insights into the functions of the MADS-box genes in cassava development, in this study, we undertook a comprehensive genome-wide identification of the MADS-box gene family in cassava. We identified a total of 86 MADS-box genes with complete domains in the cassava genome, designated as MeMADS01 to MeMADS86. Through bioinformatic analyses, we investigated the basic physicochemical properties, conserved motifs, chromosomal locations, and phylogenetic relationships of the cassava MADS-box genes. The MADS-box gene family of cassava exhibited conservation, as well as species-specific characteristics, with intron loss being a predominant mode of evolution for the MADS-box genes. Expression pattern variations in the MeMADS genes across different tissues offer insights into their potential functions. Time-ordered gene co-expression network (TO-GCN), transcriptome data, and RT-qPCR analysis suggested the responsiveness of the MADS-box genes to drought stress. Meanwhile, MeMADS12 might be involved in regulating flowering under drought conditions via an ABA (abscisic acid)-dependent pathway. These findings provide valuable resources for a deeper understanding of the biological roles of the MADS-box genes in cassava. [ABSTRACT FROM AUTHOR]

This study investigates the effects of nitrogen fertilization, irrigation, and biostimulant application on the growth and nutrient composition of Cichorium spinosum L. The experimental design included two nitrogen rates (NR100 and NR30, 100% and 30% of plant requirements), two irrigation levels (WA100 and WA50, 100% and 50% of water availability,), and foliar application of a nitrogen-rich biostimulant (BS and NoBS, biostimulated or not biostimulated). In comparison to NR100, NR30 reduced agronomical parameters leaf number, leaf area, leaf fresh, and dry weight by 13.53%, 24.93%, 20.76%, and 15.00%, respectively, whereas dry matter content was increased by 7.64%. WA50 also resulted in reduction in the agronomical characteristics by 8.62%, 7.19%, 5.53%, and 5.26, respectively, whereas the dry matter content was not affected. BS positively affected the agronomical characteristics by 7.49%, 8.01%, 7.18%, and 5.56, respectively, whereas the dry matter content was not affected. The effects of nitrogen rates and water availability suggest the more pronounced impact of nitrogen compared to water stress on the agronomical characteristics. Biostimulant application partially mitigated the effects of NR30 but was ineffective against WA50. The nutrient content of the leaves was also affected. NR30 reduced leaf nitrate, calcium, and zinc content, but increased iron, manganese, and copper concentrations. WA50 altered magnesium and zinc levels: it increased the former and decreased the latter. The interaction between nitrogen and water stress notably affected the plants' calcium content, which was higher under the NR100 x WA50 treatment. These findings provide significant insights into the perlite-based cultivation of C. spinosum L., and its resilience against drought stress. Moreover, the beneficial effects of sufficient nitrogen rates on leaf fresh weight of Cichorium spinosum L. outline the importance for improving nutrient solution management schemes. Biostimulant application demonstrated promising results and could, after further research, become a viable solution for maintaining optimal yields under nitrogen stress. [ABSTRACT FROM AUTHOR]

Drought stress, as one of the most common environmental factors, seriously affects seed- ling establishment as well as plant growth and productivity. The growth of Toona ciliata is constrained by soil moisture deficit, and drought stress can reduce its productivity and limit its suitable growing environment. To explore the molecular mechanism of Toona ciliata responding to drought stress, leaves of two-year-old Toona ciliata seedlings were used as experimental materials for transcriptome sequencing and physiological index measurements. Under drought stress, the contents of Chl, MDA, POD, SP, SS, and RWC all change differently. We performed transcriptome sequencing, obtaining 4830 differential genes. The enrichment analysis indicates that the primary effects on the leaves of Toona ciliata under drought stress are related to photosynthesis and responses to plant hormone signal transduction. Transcription factor families associated with drought resistance include the NAC, WRKY, bZIP, bHLH, AP2-EREBP, C3H, GRAS, and FRAI transcription factor families. A weighted gene co-expression network analysis (WGCNA) analysis successfully identified 10 hub genes in response to drought stress in Toona ciliata leaves. Real-time quantitative PCR (RT-qPCR) validated the reliability of the transcriptomic data, and the analysis of its results showed a close correlation with the data obtained from RNA-seq. This study clarifies the transcriptional response of Toona ciliata to drought stress, contributing to the revelation of the molecular mechanisms of drought adaptation. [ABSTRACT FROM AUTHOR]

Copyright of Anadolu Tarım Bilimleri Dergisi is the property of Ondokuz Mayis Universitesi, Ziraat Fakultesi 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.)

The purpose of this study was to determine the agro-morphological, physiological, and transcriptional characteristics of ethyl methane sulfonate (EMS)-mutagenized M3 alfalfa (Medicago sativa L.) mutants grown for 24 days under water deficit conditions following the first cutting at the blooming bud stage. Drought stress generally reduced all agro-morphological parameters measured. Cutting stress significantly reduced total chlorophyll contents of all genotypes, with the exception of mutant X20. Significant changes occurred in the levels of ascorbate peroxidase (APX), lipid peroxidation (TBARS), glutathione reductase (GR), superoxide dismutase (SOD) and crude protein levels. Drought stress considerably elevated GR levels in irrigated control (C1) and unirrigated control (C2) plants. In contrast to the other genotypes studied, mutant X20's crude protein level increased significantly after the first cutting under 24 days of water deficit conditions, compared to the level found before cutting. The expression profiles of Medicago truncatula Response to Desiccation 2 (MtRD2) and Medicago sativa proline dehydrogenase (MsProDH) genes differed based on the plant genotype and duration of drought stress. Drought stress increased MsProDH gene expression in X20, X50, and C2 plants by 4.57, 14.8, and 20.65 times, respectively. The findings of the expression study indicated that the MtRD2 gene may play a key role in stress reduction rather than drought stress per se. The results of this study revealed that cutting and drought are two independent stress variables that should be evaluated separately when evaluating genotype response to both irrigated and unirrigated growing environments in alfalfa. [ABSTRACT FROM AUTHOR]

Drought and heat are recognized as the foremost abiotic stresses influencing plant growth and yield. In response to stressful conditions, plants undergo various physiological and biochemical modifications to enhance their resilience. Among these modifications, root exudates, comprising a diverse range of organic compounds, significantly impact plant resilience to drought and heat stresses. The soil microbiome plays a crucial role in mitigating drought and heat stress by enhancing plant resilience through various mechanisms, including nutrient acquisition, hormone production, and stress signal modulation. Its interaction with root exudates further amplifies these effects, as root exudates serve as key mediators in shaping microbial communities and promoting beneficial interactions. This review enunciates the crucial role of root exudates in conferring drought and heat stress tolerance, offering novel insights into the mechanisms, root structural changes, and physiological and biochemical adaptations. The role of microorganisms and their interaction with root exudates are explored to unveil the intricate network of interactions orchestrated by root exudates in stress adaptation, mitigation and resilience. In addition, this review examines the various physiological, abiotic, and biotic factors that impact the composition and dynamics of root exudates. Deciphering the complex interactions among these elements is essential to understanding the intricacies of plant stress responses. Furthermore, root exudate extraction techniques are briefed. Overall, this review aims to better understand and drive future research focused on integrating the role of root exudates, soil microbiome for improving adaptation, mitigation and resilience of crops to abiotic stresses such as drought and heat. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology 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 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]

The development and quality of tea plants (Camellia sinensis (L.) O. Ktze.) are greatly hampered by drought stress (DS), which affects them in a number of ways, includingby interfering with their metabolism of nitrogen (N). Arbuscular mycorrhizal fungi (AMF) are known to enhance water and nutrient absorption inplants, but their specific effects on tea plant N metabolism under DS and the associated regulatory mechanisms remain unclear. This study aimed to evaluate the impact of Claroideoglomus etunicatum inoculation on N assimilation in tea plants (C. sinensis cv. Fuding Dabaicha) under well-watered (WW) and DS conditions, and to explore potential molecularmechanisms. After 8 weeks of DS treatment, root my corrhizal colonization was significantly inhibited, and the biomass of tea shoots and roots, as well as the contents of various amino acids (AAs) were reduced. However, AMF inoculation significantly increased the contents of tea polyphenols and catechins in leaves by 13.74%-36.90% under both WW and DS conditions. Additionally, mycorrhizal colonization notably increased N content by 12.65%-35.70%, various AAs by 11.88%-325.42%, and enzymatic activities associated with N metabolism by 3.80%-147.62% in both leaves and roots. Gene expression analysis revealed a universal upregulation of Nassimilation-relatedgenes (CsAMT1;2,CsAMT3;1,CsGS1,CsNADHGOGAT, CsTS2,CsGGT1, andCsADC) inAMF-colonized tea roots, regardless of water status. UnderDS condition, AMF inoculation significantly upregulated the expressions of CsNRT1;2,CsNRT1;5,CsNRT2;5,CsNR,CsGS1,CsGDH1,CsGDH2,CsTS2,CsGGT1, CsGGT3, and CsSAMDC in tea leaves. These findings suggest that AMF improved tea plant adaptability toDS by enhancingNabsorption and assimilation, accompanied by the synthesis and accumulation of various AAs, such as Glu, Gln, Asp, Lys, Arg,GABA andPro. This is achieved throughtheupregulationofNmetabolism-relatedgenes and the activation of related enzymes in tea plants under DS condition. These findings provide valuable insights into the role of AMF in regulating tea plantNmetabolism and enhancing stress tolerance. [ABSTRACT FROM AUTHOR]

Sugar beet (Beta vulgaris L) is an important sugar and cash crop, but its production is often severely affected by drought. Dehydration-responsive element-binding protein (DREB) family transcription factors are known to play important roles in drought tolerance. However, the sugar beet BvDREB gene family has never been reported. In this study, we identified the sugar beet BvDREB gene family at the genome-wide level and analyzed its structure and expression patterns to reveal the biological functions of these genes in response to drought stress. Thirty BvDREB genes were identified and divided into six subfamilies. A comprehensive analysis of the evolutionary tree, cis-acting elements, drought stress transcriptome data, real-time quantitative PCR results and potential interacting proteins of BvDREB revealed that all the BvDREB genes are responsive to drought stress and have different expression patterns under short- and long-term drought stress conditions. They play an important role in drought tolerance through regulating the ABA signal pathway, proline biosynthesis and hormone levels. This study provides important data for further functional characterization of the BvDREB genes and also lays the foundation for molecular screening and breeding of drought tolerance in sugar beet and other crop varieties. [ABSTRACT FROM AUTHOR]

Global warming is contributing to an increase in the frequency of extreme climate events, leading to more frequent droughts that pose significant abiotic stressors affecting the growth and yield of sugar beet. To address the detrimental effects of drought stress on sugar beet seedlings, this study simulated a drought environment and examined the impact of arbuscular mycorrhizal fungi (AMF) symbiosis on seedling growth. The findings revealed that AMF inoculation under drought conditions enhanced the photosynthesis rate and increased the content of photosynthetic pigments in the leaves of sugar beet. Additionally, it effectively mitigated cell membrane damage in the seedlings, elevated the levels of osmoregulatory substances, and enhanced antioxidant enzyme activities in both leaves and roots. The inoculation of AMF regulates the physiological processes associated with sugar beet growth, alleviates the adverse effects of drought stress, and promotes seedling development. Consequently, AMF can be regarded as a valuable bioregulator in sugar beet cultivation under drought conditions, providing significant practical benefits for improving sugar beet yield. [ABSTRACT FROM AUTHOR]

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Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Background: ADP-glucose pyrophosphorylase (AGPase) is the key rate-limiting enzyme in starch biosynthesis pathway, and has been identified as a potential target for manipulation strategies aimed at improving crop yield and quality. Objective: To identify the AGPase gene family members in soybean, and explore the potential implications of GmAGPS2 in drought stress tolerance. Methods: The genome-wide identification and sequence analysis of soybean AGPase gene family was carried out by bioinformatics methods. The GmAGP gene expression was analyzed using transcriptome data and quantitative real-time PCR (qRT-PCR). Furthermore, transgenic yeast strains overexpressing GmAGPS2 were generated, and their growth was observed under drought stress. Results: In this study, we searched for AGPase genes (GmAGP) in the soybean genome and identified a total of 14 GmAGP genes. The GmAGP proteins had a unique conserved NTP_transferase domain and were mainly located in the chloroplast and cytosol. Evolutionarily, the GmAGP proteins can be clustered into two distinct subgroups; within the same subgroup, they displayed a similar distribution pattern of conserved motifs. The GmAGP genes exhibited an uneven distribution on 10 chromosomes, and segmental duplication contributed to AGPase gene family expansion in soybean. The GmAGP genes presented different tissue expression pattern, in which GmAGPL6, GmAGPL9, and GmAGPL10 mainly exhibited tissue-specific expression pattern. The promoter of GmAGP genes had multiple cis-acting elements related to phytohormones and stress responses, and 8 GmAGP genes contained drought-responsive cis-acting elements. qRT‒PCR analysis demonstrated a significant upregulation expression of GmAGPL6, GmAGPL10, and GmAGPS2 in response to drought stress. Further functional analysis indicated that GmAGPS2 gene could improve yeast growth under drought stress conditions and enhance the drought tolerance of yeast. Conclusion: These results will contribute to further elucidation of the function of GmAGP genes, and offer important candidate genes for the genetic improvement of starch and yield-related traits and the breeding of high drought stress tolerance varieties in soybean. [ABSTRACT FROM AUTHOR]

The biological and organic fertilizers application under drought stress can reduce the adverse effects of this global issue and improve plant growth and development parameters. Therefore, this study was conducted in two crop years of 2020-2021 and 2021-2022 in the climatic conditions of Chalus city, Iran. The split-factorial experiment was conducted in the form of a basic randomized complete block design with 3 replications. The main factor included irrigation deficit at three levels (100, 80, and 60% of water requirement) and the secondary factors included biological fertilizer (control, mycorrhizal fungus, and Enterobacter) and organic fertilizer (no use, 16, and 24 tons per hectare) in a factorial manner. The results of the mean comparison showed that the highest seed yield was observed in the second year under 100% irrigation and application of 24 t/h of organic fertilizer and mycorrhiza at the rate of 126.1 g/m2; Subsequently, theco application of 80% water requirement and 24 t/h of organic fertilizer and Enterobacter treatments in the second year caused the highest amount of 124.3 g/m2. Generally, the 60% water requirement reduced grain yield compared to other water requirements levels. According to the results of this study, the organic and biological fertilization under drought stress conditions can significantly improve the quantitative and qualitative yield of mung bean. Therefore, it is recommended that the organic and biological fertilizers can be applied in drylands to mitigate drought stress conditions, and improve the growth, yield and quality of mung beans. [ABSTRACT FROM AUTHOR]

Drought stress significantly impairs rice germination, seedling growth, and productivity, particularly in Northeast India, where climatic changes have led to reduced rainfall. This study explores the synergistic effects of two phenolic acids, Salicylic Acid (SA) and Gallic Acid (GA), in alleviating drought stress in Kola Joha rice (Oryza sativa L.), a cultivar with a Geographical Indication tag from Assam. The experiment, conducted under controlled laboratory conditions, applied a 15% PEG solution to induce drought stress, with different treatments including exogenous application of SA and GA. The results demonstrated that both SA and GA improved germination parameters, seedling growth and seed vigor index under drought conditions. The combined treatment of SA and GA showed the best performance, enhancing root and shoot length, water content, and biomass, while mitigating the negative effects of drought stress. The study suggests that the use of these natural growth regulators can offer an effective strategy for improving rice productivity in water-scarce environments and highlights their potential for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Albizia odoratissima is a deciduous tree species belonging to the family Leguminosae. It is widely distributed in the southern subtropical and tropical areas of China and has important ecological and economic value. The growth and metabolic processes of A. odoratissima are affected by drought stress, but the molecular mechanisms remain unknown. Therefore, this study investigated the physicochemical properties, gene expression, and metabolites of A. odoratissima seedlings under drought stress. The results show that, in leaves of A. odoratissima seedlings, drought stress reduced the moisture content, chlorophyll content, photosynthetic efficiency, superoxide dismutase (SOD) activity, and gibberellin (GA) and indoleacetic acid (IAA) contents while increasing the catalase (CAT) and peroxidase (POD) activities and malondialdehyde (MDA), proline, soluble sugar, and soluble protein contents. Within the CK5 (Day 5 of control group) vs. T5 (Day 5 of drought treatment), CK10 vs. T10, CK15 vs. T15, and CK20 vs. T20 groups (CK: control group; T: drought treatment), a total of 676 differentially expressed genes (DEGs) were upregulated and 518 DEGs were downregulated, and a total of 228 and 143 differential accumulation metabolites (DAMs) were identified in the CK10 vs. T10 and CK20 vs. T20 groups. These were mainly involved in the amino acid and alkaloid metabolism pathways in the leaves of the A. odoratissima seedlings. In the amino acid and alkaloid biosynthesis pathways, the relative expression levels of the AoproA (Aod04G002740, ORTHODONTIC APPLIANCE), AoOAT (Aod07G015970, ORNITHINE-OXO-ACID TRANSAMINASE), and AoAOC3 (Aod12G005010/08G003360/05G023920/08G003000/08G003010, AMINE OXIDASE COPPER CONTAINING 3) genes increased, which concurrently promoted the accumulation of arginine, proline, piperine, cadaverine, and lysine. Furthermore, some key transcription factors in the response to drought were identified in the leaves using the weighted gene co-expression network analyses (WGCNA) method. These findings reveal that A. odoratissima seedlings respond to drought stress by improving the capacities of the antioxidant system and secondary metabolism. [ABSTRACT FROM AUTHOR]

Betaine aldehyde dehydrogenases (BADHs) are key enzymes in the biosynthesis of glycine betaine, which is an important organic osmolyte that maintains cell structure and improves plant tolerance to abiotic stresses, especially in halotolerant plants. Improving the drought tolerance of crops will greatly increase their yield. In this study, a novel BADH gene named SgBADH from Suaeda glauca was induced by drought stress or abscisic acid. To explore the biological function of SgBADH, the SgBADH gene was transformed into Arabidopsis. Then, we found SgBADH-overexpressing Arabidopsis seedlings showed enhanced tolerance to drought stress. SgBADH transgenic Arabidopsis seedlings also had longer roots compared with controls under drought stress, while SgBADH-overexpressing Arabidopsis exhibited increased glycine betaine accumulation and decreased malondialdehyde (MDA) under drought stress. Our results suggest that SgBADH might be a positive regulator in plants during the response to drought. [ABSTRACT FROM AUTHOR]

Water deficiency and potential drought periods could be important ecological factors influencing cultivation areas and productivity once different crops are established. The principal supply of vegetable oil for oil crops is oil palm, and new challenges are emerging in the face of climatic changes. This study investigated the photosynthetic performance of 12 genotypes of Elaeis exposed to drought stress under controlled conditions. The assay included genotypes of Elaeis guineensis, Elaeis oleifera, and the interspecific O×G hybrid (E. oleifera × E. guineensis). The principal results showed that the E. guineensis genotype was the most efficient at achieving photosynthesis under drought stress conditions, followed by the hybrid and E. oleifera genotypes. The physiological parameters showed good prospects for vegetal breeding with different O×G hybrids, mainly because of their ability to maintain the equilibrium between CO2 assimilation and stomatal aperture. We validated 11 genes associated with drought tolerance, but no differences were detected. These results indicate that no allelic variants were represented in the RNA during sampling for the validated genotypes. In conclusion, this study helps to define genotypes that can be used as parental lines for oil palm improvement. The gas exchange data showed that drought stress tolerance could define guidelines to incorporate the available genetic resources in breeding programs across the early selection in nursery stages. [ABSTRACT FROM AUTHOR]

Caffeic acid O-methyltransferase (COMT), as a multifunctional enzyme involved in various physiological and biochemical processes in lignin metabolism, plays an important role in a plant's response to stress. In this study, we isolated COMT family members from the walnut genome by bioinformatics and analyzed their physicochemical properties and their expression under drought stress to provide gene resources for drought resistance in walnut. The results showed that 33 COMT genes were identified from walnuts and distributed on different chromosomes. The molecular weight of proteins varies greatly. According to the phylogenetic tree, the family can be divided into seven subgroups, which are relatively conservative in evolution and closely related to Arabidopsis thaliana. Promoter analysis showed that the promoter of the walnut COMT gene contains rich cis-elements of plant hormone response and stress response, and the real-time fluorescence scale name can be significantly induced by drought stress. Compared with wild-type Arabidopsis, overexpression JrCOMT19 significantly increased the enzyme activity (SOD, POD, and CAT) and proline content. Meanwhile, overexpression of JrCOMT19 significantly increased the lignin content and expression of related genes. Therefore, JrCOMT plays an important role in responding to drought in walnuts, and overexpression JrCOMT19 can improve the resistance to drought stress by increasing lignin content, antioxidant enzyme activity, and osmotic substance content. [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]

Hydrologic stress is increasing in Fremont cottonwood (Populus fremontii) forests across the southwestern United States because of increased temperature and streamflow diversion. The spatial variability of this stress is large yet poorly understood. Along the Yampa and Green Rivers in Colorado and Utah, vapour pressure deficit and flow diversions increase downstream. To investigate effects of this gradient on cottonwoods, we measured the percent live canopy and height of randomly selected trees at three sites: Deerlodge Park on the Yampa River (DLP), Island Park on the upper Green (ILP) and Canyonlands National Park on the lower Green (CAN). From these same trees, we took increment cores to understand differences in tree growth in each forest over time. We then related tree metrics to local water availability, streamflow and climatic data. Cottonwoods at CAN were shorter and had lower percent live canopy and growth rate than similarly aged trees upstream. CAN trees that grew higher above the water surface also tended to have lower tree growth, height and live canopy percentage. Furthermore, the correlation between tree growth and maximum vapour pressure deficit showed a much stronger negative shift since 1990 at CAN than at the other sites. All of these differences suggest higher hydrologic stress at CAN, which we attribute to the combined effects of peak flow declines from Flaming Gorge Reservoir, flow diversion and the higher and increasing vapour pressure deficit at CAN. Further research on the variability of hydrologic stress on cottonwoods could help managers anticipate and mitigate the effects of drought stress in these iconic forests. [ABSTRACT FROM AUTHOR]

Main conclusion: The PcHsp70-5 enhances drought stress tolerance in transgenic Arabidopsis thaliana by upregulating stress tolerance genes and antioxidant enzyme activities. Heat shock proteins (HSPs) constitute a class of evolutionarily conserved proteins synthesized by organisms in response to various adverse environmental stimuli such as elevated temperatures, drought, hormonal fluctuations, high salt concentrations, and mechanical stress. However, research on HSPs has predominantly focused on model plants and crops, whereas their functions in desert plants have not been well investigated. This study analyzed the transcriptome of Pugionium cornutum and identified the complete ORFs of 25 genes of the PcHsp70 family genes. Their expression levels under drought stress were investigated using existing RNA-seq data. PcHsp70-5 genes exhibited high expression levels in both roots and leaves under drought stress. Consequently, the PcHsp70-5 genes were cloned and transformed into Arabidopsis thaliana for further analysis of their roles in drought stress response. Real-time fluorescence quantitative PCR (qRT-PCR) analysis demonstrated that both, drought stress and ABA, induced PcHsp70-5 expression. Under drought conditions, transgenic Arabidopsis plants exhibited markedly enhanced growth compared to wild-type plants, as evidenced by improved survival rates, root length, fresh weight, chlorophyll content, and reduced levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in leaves, indicating that PcHsp70-5 overexpression mitigated growth inhibition and oxidative damage induced by drought stress. Subsequent research revealed that PcHsp70-5 overexpression significantly augmented the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and increased the proline content in transgenic Arabidopsis under drought conditions, alongside a significant increase in the expression levels of genes related to stress tolerance. This suggests that PcHsp70-5 enhances drought stress tolerance in transgenic Arabidopsis by upregulating stress tolerance genes and antioxidant enzyme activities. [ABSTRACT FROM AUTHOR]

Introduction: Water shortage has become a global problem and has caused many problems in agriculture and food supply for the growing world. Barley (Hordeum vulgare L.) as the fourth mostly-cultivated cereal, is one of the most strategic crop plants which is produced almost all over the world as a source of and important staple food and animal feed (Thabet et al., 2020). Food uncertainty is a comprehensive obstacle becomes more serious hazard all over the world in particular in developing countries for the sake of overpopulation and dwindling accessibility of croplands, water and other resources related to agricultural scopes. Water scarcity, results in plenty of disturbances in plant functions like cell division and elongation, water and nutrients relations, photosynthesis, enzymes activity, stomata movement, assimilate partitioning, respiration, oxidative damage, growth, and productivity, as several types of researches show that water shortage in the soil cause many disorders in plant tissues, which in turn leads to a punctual diminish in the photosynthesis rate (Todorova et al., 2022). In such a trouble circumstances, most of the plants are not capable to absorb abundant water, which is required for optimized growth (Danish et al., 2020). Materials and methods: To investigate the impact of different irrigation regimes as well as foliar application of methyl jasmonate on growh, physiological and biochemical characteristics of barley varieties, an experimental research using factorial split plot design in 3 replications was carried out in experimental farm of the faculty of agriculture at the University of Zanjan in 2021-2022 cultivation season. In this experiment, irrigation regimes as the main factor, including complete irrigation as the control, withholding water in flowering stage, withholding water in grain filling period and complete dry farming, varieties as the secondary factor including Bahman, Sahand, Jolgeh, Abidar as well as Ansar, and foliar application of methyl jasmonate including without spraying (control) and spraying 50 μmol of methyl jasmonate were investigated. Results showed that the effect of irrigation regime had significant impact on almost all of the characteristics except chlorophyll a/b. Results and discussion: Varieties showed considerable difference from the aspect of height, concentration of soluble sugar and grain yield. Effect of Methyl jasmonate on the relative water content (RWC), photosynthetic pigments, soluble sugar content, proline content, Malondialdehyde (MDA) and grain yield was significant. The highest grain yield (4762 kg ha-1) was detected when variety of Jolgeh was irrigated normally and was sprayed by 50 μmol of Methyl jasmonate and the lowest grain yield (432 kg ha-1) was seen when variety of Bahman was dry-farmed without foliar application of methyl jasmonate. Conclusion: The current study illustrated that barley can be grown in drought stress conditions if the right management is set on its cultivation. Methyl jasmonate showed a significant impact on the growth characteristics, biochemical and physiological attributes of the barley, despite the fact that drought had substantial adverse effects on the studied parameters of barley. However, drought resulted in different properties in barley varieties. [ABSTRACT FROM AUTHOR]

Sesamum indicum L. (sesame) is a traditional oilseed crop grown extensively in tropical and subtropical areas. In recent years, it has received more attention due to the health-promoting properties of its seed oil. Although production increased globally, its productivity is very low in different regions due to the harmful effects of biotic and abiotic stresses. Therefore, studying the environmental stress response mechanisms for improving productivity and yield is crucial in sesame research. Drought is a major abiotic stress that adversely affects sesame productivity worldwide. Sesame is typically a drought-tolerant crop; however, intense and prolonged drought limits its growth and impairs flower production, ultimately affecting the yield and sometimes resulting in plant mortality. Different varieties of sesame exhibit contrasting responses to drought stress, indicating the existence of different molecular mechanisms. The paper discusses the advancement in screening methodologies for drought tolerance, inheritance, biochemical and molecular aspects, transgenic approaches, and quantitative trait loci (QTL) associated with drought stress tolerance in sesame with the aid of citation network analysis (CNA). [ABSTRACT FROM AUTHOR]

Drought stress (DS) is a recurrent and severe meteorological challenge affecting agricultural regions globally, leading to significant shifts in plant species distribution and substantial reductions in crop yields. The seasonal occurrence, intensity, and duration of DS vary in response to changing climatic conditions. Plants deploy various physio-biochemical and anatomical alterations to combat such conditions, including stomatal closure, modified root growth and architecture, shifts in metabolic pathways, and altered physiological responses. Moreover, metabolic shifts and physio-chemical adaptations under DS often shorten plant life cycles, reducing yields. Nevertheless, the impact of DS on plants depends on the soil water gradient, precipitation duration and degree, plant species, and developmental stage. This review elucidates the complex effects of DS on trait variations, highlighting the current knowledge on advances in genetic engineering, breeding, and agronomic approaches and exploring potential strategies to increase yield and develop drought-resistant crops. [ABSTRACT FROM AUTHOR]

A key element in the effective recovery of plants after drought is slowing down of their senescence accelerated during the drought. Therefore, in this paper the relationships between hydrogen peroxide content and effective recovery during rehydration after water stress were analyzed. The study focused on two DH lines of winter triticale with different regeneration potential, as shown by different numbers of lateral stems with ears, grown during rehydration after water stress. During rehydration, the GZDH27 line grows two to three lateral stems with ears, whereas the GZDH88 line grows a single lateral stem with ear. The two DH lines of winter triticale showed comparable responses to the drought stress but their responses to rehydration after the drought stress were clearly different. Results revealed, that the increased accumulation of hydrogen peroxide, which was induced during the drought, can be maintained during rehydration, thus stimulating plant senescence. In the line GZDH88, rehydration did not slow down drought-induced senescence. This was manifested by higher levels of hydrogen peroxide, accompanied by lower levels of chlorophyll in the flag leaves of GZDH88 plants, as the result of which only one lateral stem was formed during rehydration. However, development of one lateral stems during rehydration in the GZDH88 line allowed for smaller yield loss than in the GZDH77 line, that developed of three lateral stems during rehydration. The efficient production of carbohydrates and their effective allocation into the ears of the lateral stems required considerable energy expenditure in the GZDH27 line. Our results indicate that growing three lateral stems with ears during rehydration does not guarantee limitation of grain yield loss. However, to reach the final conclusion, it is important to evaluate a greater number of triticale genotypes under drought stress and rehydration during various stages of a plants development. [ABSTRACT FROM AUTHOR]

Long-term drought stress has irreversible effects on potato growth and reduces yield. Uniconazole can alleviate the growth inhibition and plant damage resulting from drought stress. In the current study, the effects of drought stress on the leaf physiology and yield of two potato varieties (Kexin No. 1, drought-tolerant, and Atlantic, drought-sensitive) and the ability of uniconazole to promote growth and productivity under drought conditions were studied. The results showed that uniconazole could effectively alleviate the degradation of chlorophyll under drought stress, and drought significantly inhibited the photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) of the leaves of the two potato varieties. Exogenous uniconazole effectively alleviated the inhibitory effect of drought on the photosynthetic parameters of potato leaves. Compared with drought treatment, uniconazole treatment reduced malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2−) production in the leaves of Kexin No. 1 and Atlantic plants and increased the activity of antioxidant enzymes, alleviating the loss of yield factors caused by drought stress. In addition, the antioxidant enzyme activity and nonenzymatic antioxidant activity of both varieties increased in response to drought stress. Drought + uniconazole treatment further increased the contents of the osmotic adjustment substances soluble protein and proline and ascorbate-glutathione (ASA-GSH) cycle products and substrates, including ascorbic acid (ASA), dehydroascorbate (DHA), glutathione (GSH) and oxidized glutathione (GSSG). Drought + uniconazole treatment also increased the ratio of ASA/DHA and GSH/GSSG in the two potato varieties under drought stress. This enhancement elevated the levels of reducing power and antioxidant capacity in the leaves, thus reducing the impacts of reactive oxygen species on the cell membrane. The drought-tolerant variety Kexin No. 1 exhibited a greater recovery than did the drought-sensitive variety Atlantic. These results provide a valuable reference for understanding the mechanism of drought resistance in potato plants and the effectiveness of uniconazole in alleviating drought-induced stress. [ABSTRACT FROM AUTHOR]

Abstract Background Accumulation of coumarins plays key roles in response to immune and abiotic stress in plants, but the genetic adaptation basis of controlling coumarins in perennial woody plants remain unclear. Results We detected 792 SNPs within 334 genes that were significantly associated with the phenotypic variations of 15 single-metabolic traits and multiple comprehensive index, such as principal components (PCs) of coumarins metabolites. Expression quantitative trait locus mapping uncovered that 337 eQTLs associated with the expression levels of 132 associated genes. Selective sweep revealed 55 candidate genes have potential selective signature among three geographical populations, highlighting that the coumarins biosynthesis have been encountered forceful local adaptation. Furthermore, we constructed a genetic network of seven candidate genes that coordinately regulate coumarins biosynthesis, revealing the multiple regulatory patterns affecting coumarins accumulation in Populus tomentosa. Validation of candidate gene variations in a drought-tolerated population and DUF538 heterologous transformation experiments verified the function of candidate genes and their roles in adapting to the different geographical conditions in poplar. Conclusions Our study uncovered the genetic regulation of the coumarins metabolic biosynthesis of Populus, and offered potential clues for drought-tolerance evaluation and regional improvement in woody plants.

IntroductionGiven the expected population growth in the coming years and the necessity to provide food for people, legumes, especially chickpeas (Cicer arietinum. L), hold significant importance in terms of economics, nutrition, soil improvement, and crop rotation. Legumes are considered one of the most important sources of protein in most developing countries. Researchers believe that early cultivation of chickpeas leads to better performance due to the longer vegetative growth period and concurrent reproductive phase with appropriate rainfall and desirable moisture. On the other hand, studies show that spring planting of chickpeas leads to a reduction in all growth factors due to the simultaneous sensitive growth stages with water deficit and drought stress. This study was conducted to grouping of candidate chickpea genotypes in response to water deficit based on their yield performance and components at different planting dates. Materials and MethodsThis study was conducted at the research farm station of the Faculty of Agriculture, Ferdowsi University of Mashhad, in the year 2018-19. In this research, six genotypes and two cultivars were evaluated in a randomized complete block design with four replications as a split-plot design. Seeds were obtained from the seed bank collection of Research Center for Plant Sciences, Ferdowsi University of Mashhad. Planting was done in two dates in 5 March and 13 April with a density of 40 plants per square meter. Also, irrigations were done only at two stages; the first stage was irrigated with the purpose of achieving the emergence and the second irrigation at the time of 50% flowering with 20 mm in both stages. To measure traits such as emergence time, flowering time (50% of plants in flowering stage) and biomass, plant height, number of pods per plant, percentage of fertile pods, and 100-seed weight at the end of the growth stage and harvest time, five plants were randomly selected from each plot, and the desired traits were examined and recorded. At the time of full maturity and drying of the plants, after removing half a square meter margin from each plot, biological and seed yield were measured, and for calculating biological yield, the dry weight of seeds was added to the dry weight of plant residues. Results and DiscussionThe results indicated a significant superiority in all traits for the first planting date (5 March) compared to the second planting date (13 April). Significant differences were observed among the different genotypes in terms of emergence percentage, days to maturity, plant height, days to flowering, biological yield, podding, and seed yield. Genotype MCC352 had the highest number of pods per plant (34 pods), and genotype MCC427 had the highest number of days to flowering. Genotype MCC537 was superior in plant height and biological yield, but genotype MCC696 was superior in days to maturity and seed yield, indicating that these two genotypes had better responses to environmental conditions. Based on cluster analysis of chickpea genotypes in the first planting date, eight genotypes were classified into four clusters. Cluster 1 included genotypes MCC352, MCC537, MCC552, MCC80, and Jam cultivar. Cluster 2 included Samin cultivar. Cluster 3 included genotype MCC427, and cluster 4 included genotype 696MCC. Cluster 1 had the highest coefficients in terms of emergence percentage and days to maturity, and cluster 2 had the highest coefficients of days to maturity and days to flowering. Similarly, in the second planting date, eight chickpea genotypes were classified into three clusters. Cluster 1 included genotypes MCC696, MCC537, MCC552, MCC80, and Jam cultivar. Cluster 2 included genotypes MCC352 and MCC427. Cluster 3 included Samin cultivar. Cluster 1 had the highest coefficients in terms of emergence percentage and days to maturity, and cluster 2 had the highest coefficients of days to maturity and emergence percentage. Furthermore, the Principal Component Analysis of the studied genotype traits showed that in the first planting date (5 March), PC1 (43.4%) and PC2 (25.7%) accounted for a total of 69.1% of the variance, while in the second planting date, PC1 (36.8%) and PC2 (27%) accounted for a total of 63.3% of the variance. Overall, the studied genotypes had better performance and yield components in the first planting date. ConclusionsIn general, it can be concluded that delayed planting and exposure to drought stress during the critical growth stages of the plant at the end of the season resulted in a decrease in chickpea yield and its components. It was observed that planting chickpea on time to avoid late drought stress at flowering and podding stages would lead to a better yield and its components.

Abstract The impact of climate change on agricultural production is apparent due to declining irrigation water availability vis-à-vis rising drought stress, particularly affecting summer crops. Growing evidence suggests that zinc (Zn) supplementation may serve as a potential drought stress management strategy in agriculture. Field studies were conducted using soybean (Glycine max var. Saba) as a model crop to test whether foliar application of zinc oxide nanoparticles (ZnO-NPs) or conventional Zn fertilizer (ZnSO4) would mitigate drought-related water stress and improve soybean yield. Each fertilizer was foliar applied twice at a two-week interval during the flowering stage. Experiments were concurrently conducted under non-drought conditions (70% field capacity) for comparison. Results showed drought significantly reduced relative water content, chlorophyll-a, and chlorophyll-b in untreated control plants by 35.7%, 47.7%, and 41.4%, respectively, compared to non-drought conditions (p

Abstract Background Cotton serves as a primary source of natural fibers crucial for the textile industry. However, environmental elements such as drought have posed challenges to cotton cultivation, resulting in adverse impacts on both production and fiber quality. Improving cotton’s resilience to drought could mitigate yield losses and foster the expansion of cotton farming. Rab7 protein, widely present in organisms, controls the degradation and recycling of cargo, and has a potential role in biotic and abiotic tolerance. However, comprehensive exploration of the Rab7 gene family in Gossypium remains scarce. Results Herein, we identified a total of 10, 10, 20, and 20 Rab7 genes through genome-wide analysis in Gossypium arboreum, Gossypium raimondii, Gossypium hirsutum, and Gossypium barbadense, respectively. Collinearity analysis unveiled the pivotal role of whole genome or segmental duplication events in the expansion of GhRab7s. Study of gene architecture, conserved protein motifs, and domains suggested the conservation of structure and function throughout evolution. Exploration of cis-regulatory elements revealed the responsiveness of GhRab7 genes to abiotic stress, corroborated by transcriptome analysis under diverse environmental stresses. Notably, the greatly induced expression of GhRab7B3-A under drought treatment prompted us to investigate its function through virus-induced gene silencing (VIGS) assays. Silencing GhRab7B3-A led to exacerbated dehydration and wilting compared with the control. Additionally, inhibition of stomatal closure, antioxidant enzyme activities and expression patterns of genes responsive to abiotic stress were observed in GhRab7B3-A silenced plants. Conclusions This study sheds light on Rab7 members in cotton, identifies a gene linked to drought stress, and paves the way for additional investigation of Rab7 genes associated with drought stress tolerance.

Societal Impact Statement Research efforts in plant biology have often been focused on sequenced and well‐studied ‘model’ organisms. Despite the advent of relatively inexpensive genome sequencing, most plant taxonomic groups are underrepresented, with few species that ‘represent’ the diversity of whole genera. This study describes an economical guide to sequencing a non‐model organism, which may be useful in reducing the cost of sequencing more species within genera and across plant life. This method was used to develop Kalanchoë blossfeldiana as a resource for comparing C3 and the water‐conserving mode of photosynthesis known as Crassulacean acid metabolism (CAM) within the same plant. Summary Despite the increasing number of well‐studied plant species with well‐annotated genomes across plant life, there are few densely sampled genera with more than a couple of genome sequences representing the diversity of whole genera. Here, we develop an economic approach to full‐genome sequencing that could be used to sequence many species within a genus. We made use of the Nanopore rapid sequencing kit to assist in plant genome assembly, dramatically reducing the cost. Here we applied this method to cost‐effectively develop genomic resources for Kalanchoë blossfeldiana, a commercially important ornamental, in which Crassulacean Acid Metabolism (CAM), a water‐conserving mode of photosynthesis can be induced. We present a physiological and biochemical characterisation of Kalanchoe blossfeldiana with its nuclear and chloroplastic genome and a comparative C3, CAM dusk transcriptome. We apply this approach to a complex tetraploid genome, making use of a relative species for chromosomal scaffolding to reduce assembly ploidy, we provide a resource for future gene expression studies. We highlight its limitations, e.g. the need for deeper sequencing to accurately resolve genome structure and haplotypes without using a relative species for scaffolding. The study demonstrates the merits of K. blossfeldiana as a comparative system for studying C3 and CAM within a plant and has identified substantial changes in the dusk transcriptome between young C3 and mature CAM K. blossfeldiana leaves in response to age‐induced CAM, and shows that in the absence of abiotic stress, CAM induction still involves the engagement of drought and abscisic acid (ABA) response pathways.

The growth and yield of tea plants are seriously limited by drought stress. Fatty acid desaturases (FADs) contribute to the mediation of membrane fluidity in response to different stresses, although the role of ω-3 FAD (Omega-3 fatty acid desaturase)-mediated damage induced by drought stress in tea plants is poorly understood. In this study, drought stress significantly promoted the synthesis of C18:3 (linolenic acid) and the expression level of CsFAD3. Yeast experiments further demonstrated that CsFAD3 can convert C18:2 to C18:3, and that the 35S:GFP-CsFAD3 fusion protein was localized in the endoplasmic reticulum of Nicotiana benthamiana cells. CsFAD3-silenced tea leaves exhibited poor drought tolerance, with a lower Fv/Fm and a higher malondialdehyde (MDA) content than the control plants. However, transgenic 35S:CsFAD3 Arabidopsis plants showed the opposite phenotypes. In addition, the jasmonic acid (JA) content and the expression levels of CsLOX2, CsLOX4, CsAOS, CsAOC3 and CsOPR2 were significantly reduced in CsFAD3-silenced leaves under drought stress. However, no substantial difference in the salicylic acid (SA) content was detected under normal or drought conditions. An analysis of Atcoi1 (JA receptor) or Atnpr1 (SA receptor) mutant Arabidopsis plants in 35S:CsFAD3 backgrounds further revealed that knockout of Atcoi1 impaired the drought-tolerant phenotypes of CsFAD3 overexpression lines. Therefore, this study demonstrated that CsFAD3 plays a crucial role in drought tolerance by mediating JA pathways.

Abstract Background Precision phenotyping of short-term transpiration response to environmental conditions and transpiration patterns throughout wheat development enables a better understanding of specific trait compositions that lead to improved transpiration efficiency. Transpiration and related traits were evaluated in a set of 79 winter wheat lines using the custom-built “DroughtSpotter XXL” facility. The 120 l plant growth containers implemented in this phenotyping platform enable gravimetric quantification of water use in real-time under semi-controlled, yet field-like conditions across the entire crop life cycle. Results The resulting high-resolution data enabled identification of significant developmental stage-specific variation for genotype rankings in transpiration efficiency. In addition, for all examined genotypes we identified the genotype-specific breakpoint in transpiration in response to increasing vapour pressure deficit, with breakpoints ranging between 2.75 and 4.1 kPa. Conclusion Continuous monitoring of transpiration efficiency and diurnal transpiration patterns enables identification of hidden, heritable genotypic variation for transpiration traits relevant for wheat under drought stress. Since the unique experimental setup mimics field-like growth conditions, the results of this study have good transferability to field conditions.

Abstract Drought stress imposes a serious challenge to cultivate wheat, restricting its growth. Drought reduces the capability of plant to uptake essential nutrients. This causes stunted growth, development and yield. Traditional ways to increase wheat growth under drought stress have shortcomings. Using plant-growth-promoting rhizobacteria (PGPR) has proved feasible and eco-friendly way to enhance wheat growth even under the drought stress. Combining PGPR in consortiums further boosts up their effects. In this study, we have checked the efficacy of drought-tolerant Bacillus halotolerans, Pseudomonas sihuiensis and Bacillus atrophaeus in combination. These strains were allowed to grow on PEG 6000 with concentrations (-0.15, -0.49, -0.73 and − 1.2) Mega Pascal (MPa) alone and in combination. Furthermore, Fourier transmission infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used. Their biochemical traits such as solubilization of K, P and Zn and the synthesis of siderophore, indole acetic acid (IAA), protease, amylase, hydrogen cyanide (HCN) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase were done. In addition to this, we investigated the optimum folic acid concentration i.e 150 ppm for wheat against drought stress. We conducted a pot experiment to check the growth-enhancing and drought-mitigating effects of consortium and folic acid alone and in combination. As a result, we found a significantly increased wheat biomass, relative water content (RWC), chlorophyll content, antioxidants including glutathione reductase and total soluble sugars and protein content under all treatments. However, the combined treatment of bacterial consortium and folic acid showed maximum potential to boost wheat growth and survival even under drought. We also investigated the minerals uptake by wheat after the treatments and found maximum nutrient uptake under the co-effect of folic acid and bacterial consortium We believe this is the first study that has investigated the optimal dose of folic acid for wheat. Our research is also novel in that we seek to investigate the effects of folic acid along with a bacterial consortium comprising Bacillus halotolerans, Pseudomonas sihuiensis and Bacillus atrophaeus on wheat grown under the drought stress.

The investigations were made on Moringa oleifera, a miraculous plant having an excellent nutritive and pharmaceutical importance, under saline and drought conditions. The effect of salt stress on morphological parameters under 200 mM NaCl concentrations including height of plant, number of leaves, root length along with their biomass were examined with the interval of 30 and 60 days, which significantly resulted in a decreased height of plant, number of leaves and their biomass. Hence, growing Moringa oleifera under highly saline conditions may not be recommended but it can be grown under moderate saline conditions. Growth, total biomass and physical parameters of the investigated plant were also analyzed under drought conditions. Treatment set was irrigated with 20% less than the total field capacity while control was irrigated with 100% according to total field capacity. Some growth parameters were measured after 30 and 60 days including stem height, number of leaves, root length and fresh and dry weights of stem, root and leaves. Drought stress surprisingly gave good results after 60 days of an increased tolerance with growing age, hence it showed that. It is a potential plant species to be planted in arid and semi-arid areas because of its drought loving nature.