Combining proximal and remote sensing to assess 'Calatina' olive water status.

Developing an efficient and sustainable precision irrigation strategy is crucial in contemporary agriculture. This study aimed to combine proximal and remote sensing techniques to show the benefits of using both monitoring methods, simultaneously assessing the water status and response of 'Calatina' olive under two distinct irrigation levels: full irrigation (FI), and drought stress (DS, -3 to -4 MPa). Stem water potential (Ψstem) and stomatal conductance (gs) were monitored weekly as reference indicators of plant water status. Crop water stress index (CWSI) and stomatal conductance index (Ig) were calculated through ground-based infrared thermography. Fruit gauges were used to monitor continuously fruit growth and data were converted in fruit daily weight fluctuations (ΔW) and relative growth rate (RGR). Normalized difference vegetation index (NDVI), normalized difference RedEdge index (NDRE), green normalized difference vegetation index (GNDVI), chlorophyll vegetation index (CVI), modified soil-adjusted vegetation index (MSAVI), water index (WI), normalized difference greenness index (NDGI) and green index (GI) were calculated from data collected by UAV-mounted multispectral camera. Data obtained from proximal sensing were correlated with both Ψstem and gs, while remote sensing data were correlated only with Ψstem. Regression analysis showed that both CWSI and Ig proved to be reliable indicators of Ψstem and gs. Of the two fruit growth parameters, ΔW exhibited a stronger relationship, primarily with Ψstem. Finally, NDVI, GNDVI, WI and NDRE emerged as the vegetation indices that correlated most strongly with Ψstem, achieving high R2 values. Combining proximal and remote sensing indices suggested two valid approaches: a more simplified one involving the use of CWSI and either NDVI or WI, and a more comprehensive one involving CWSI and ΔW as proximal indices, along with WI as a multispectral index. Further studies on combining proximal and remote sensing data will be necessary in order to find strategic combinations of sensors and establish intervention thresholds.

Contrasting drought tolerance traits of woody plants is associated with mycorrhizal types at the global scale.

It is well-known that the mycorrhizal type of plants correlates with different modes of nutrient cycling and availability. However, the differences in drought tolerance between arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) plants remains poorly characterized. We synthesized a global dataset of four hydraulic traits associated with drought tolerance of 1457 woody species (1139 AM and 318 EcM species) at 308 field sites. We compared these traits between AM and EcM species, with evolutionary history (i.e. angiosperms vs gymnosperms), water availability (i.e. aridity index) and biomes considered as additional factors. Overall, we found that evolutionary history and biogeography influenced differences in hydraulic traits between mycorrhizal types. Specifically, we found that (1) AM angiosperms are less drought-tolerant than EcM angiosperms in wet regions or biomes, but AM gymnosperms are more drought-tolerant than EcM gymnosperms in dry regions or biomes, and (2) in both angiosperms and gymnosperms, variation in hydraulic traits as well as their sensitivity to water availability were higher in AM species than in EcM species. Our results suggest that global shifts in water availability (especially drought) may alter the biogeographic distribution and abundance of AM and EcM plants, with consequences for ecosystem element cycling and ultimately, the land carbon sink.

A Bamboo HD-Zip Transcription Factor PeHDZ72 Conferred Drought Tolerance by Promoting Sugar and Water Transport.

Drought drastically affects plant growth, development and productivity. Plants respond to drought stress by enhancing sugar accumulation and water transport. Homeodomain-leucine zipper (HD-Zip) transcription factors (TFs) participate in various aspects of plant growth and stress response. However, the internal regulatory mechanism of HD-Zips in moso bamboo (Phyllostachys edulis) remains largely unknown. In this study, we identified an HD-Zip member, PeHDZ72, which was highly expressed in bamboo shoots and roots and was induced by drought. Furthermore, PeSTP_46019, PeSWEET_23178 and PeTIP4-3 were identified as downstream genes of PeHDZ72 in moso bamboo by DAP-seq. The expressions of these three genes were all induced by drought stress. Y1H, DLR and GUS activity assays demonstrated that PeHDZ72 could bind to three types of HD-motifs in the promoters of these three genes. Overexpression of PeHDZ72 led to a remarkable enhancement in drought tolerance in transgenic rice, with significantly improved soluble sugar and sucrose contents. Meanwhile, the expressions of OsSTPs, OsSWEETs and OsTIP were all upregulated in transgenic rice under drought stress. Overall, our results indicate that drought stress might induce the expression of PeHDZ72, which in turn activated downstream genes PeSTP_46019, PeSWEET_23178 and PeTIP4-3, contributing to the improvement of cellular osmotic potential in moso bamboo in response to drought stress.

Evaluation of barley genotypes for drought adaptability: based on stress indices and comprehensive evaluation as criteria.

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

Diversity in stomatal and hydraulic responses to post-flowering drought in common (Phaseolus vulgaris) and tepary (P. acutifolius) beans.

Plants differ widely in how soil drying affects stomatal conductance (gs) and leaf water potential (ψleaf), and in the underlying physiological controls. Efforts to breed crops for drought resilience would benefit from a better understanding of these mechanisms and their diversity. We grew 12 diverse genotypes of common bean (Phaseolus vulgaris L.) and four of tepary bean (P. acutifolius; a highly drought resilient species) in the field under irrigation and post-flowering drought, and quantified responses of gs and ψleaf, and their controls (soil water potential [ψsoil], evaporative demand [Δw] and plant hydraulic conductance [K]). We hypothesised that (i) common beans would be more "isohydric" (i.e., exhibit strong stomatal closure in drought, minimising ψleaf decline) than tepary beans, and that genotypes with larger ψleaf decline (more "anisohydric") would exhibit (ii) smaller increases in Δw, due to less suppression of evaporative cooling by stomatal closure and hence less canopy warming, but (iii) larger K declines due to ψleaf decline. Contrary to our hypotheses, we found that half of the common bean genotypes were similarly anisohydric to most tepary beans; canopy temperature was cooler in isohydric genotypes leading to smaller increases in Δw in drought; and that stomatal closure and K decline were similar in isohydric and anisohydric genotypes. gs and ψleaf were virtually insensitive to drought in one tepary genotype (G40068). Our results highlight the potential importance of non-stomatal mechanisms for leaf cooling, and the variability in drought resilience traits among closely related crop legumes.

Removal of the C4-domain preserves the drought tolerance enhanced by CsMYB4a and eliminates the negative impact of this transcription factor on plant growth.

The MYB4 transcription factor family regulates plant traits. However, their overexpression often results in undesirable side effects like growth reduction. We have reported a green tea (Camellia sinensis) MYB4 transcription factor (CsMYB4) that represses the phenylpropanoid and shikimate pathways and stunts plant growth and development. In the current study, we observed that in CsMYB4a transgenic tobacco (Nicotiana tabacum) plants, primary metabolism was altered, including sugar and amino acid metabolism, which demonstrated a pleiotropic regulation by CsMYB4a. The CsMYB4a transgenic tobacco plants had improved drought tolerance, which correlated to alterations in carbohydrate metabolism and an increase in proline content, as revealed by metabolic profiling and transcriptomic analysis. To mitigate the undesirable repressive side effects on plant traits, including dwarfism, shrunken leaves, and shorter roots of CsMYB4a transgenic plants, we deleted the C4 domain of CsMYB4a to obtain a CsMYB4a-DC4 variant and then overexpressed it in transgenic plants (CsMYB4a-DC4). These CsMYB4a-DC4 plants displayed a normal growth and had improved drought tolerance. Metabolite analysis demonstrated that the contents of carbohydrates and proline were increased in these transgenic plants. Our findings suggest that  an approriate modification of TFs can generate novel crop traits, thus providing potential agricultural benefits and expanding its application to various crops. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-024-00149-5.

Drought stress enhances plastid-mediated RNA interference for efficient the willow leaf beetle management.

Plastid-mediated RNA interference has emerged as a promising and effective approach for pest management. By expressing high levels of double-stranded RNAs (dsRNAs) in plastid that target essential pest genes, it has been demonstrated to effectively control certain herbivorous beetles and spider mites. However, as plants are sessile organisms, they frequently experience a combination of biotic and abiotic stresses. It remains unclear whether abiotic stress, such as drought stress, influences the accumulation of dsRNAs produced in plastids and its effectiveness in controlling pests. In this study, we aimed to investigate the effects of drought stress on dsACT expression in transplastomic poplar plants and its control efficiency against the willow leaf beetle (Plagiodera versicolora). Our findings revealed that drought stress did not significantly affect the dsRNA contents in transplastomic poplar plants, but it did lead to higher mortality of insect larvae. This increased mortality may be attributed to increased levels of jasmonic acid and cysteine proteinase inhibitor induced by water deficit. These results contribute to understanding of the mechanisms linking water deficit in plants to insect performance and provide valuable insights for implementing appropriate pest control strategies under drought stress conditions.

Identification of Drought Stress-Responsive Genes in Rice by Random Walk with Multi-Restart Probability on MultiPlex Biological Networks.

Exploring drought stress-responsive genes in rice is essential for breeding drought-resistant varieties. Rice drought resistance is controlled by multiple genes, and mining drought stress-responsive genes solely based on single omics data lacks stability and accuracy. Multi-omics correlation analysis and biological molecular network analysis provide robust solutions. This study proposed a random walk with a multi-restart probability (RWMRP) algorithm, based on the Restarted Random Walk (RWR) algorithm, to operate on rice MultiPlex biological networks. It explores the interactions between biological molecules across various levels and ranks potential genes. RWMRP uses eigenvector centrality to evaluate node importance in the network and adjusts the restart probabilities accordingly, diverging from the uniform restart probability employed in RWR. In the random walk process, it can be better to consider the global relationships in the network. Firstly, we constructed a MultiPlex biological network by integrating the rice protein-protein interaction, gene pathway, and gene co-expression network. Then, we employed RWMRP to predict the potential genes associated with rice tolerance to drought stress. Enrichment and correlation analyses resulted in the identification of 12 drought-related genes. We further conducted quantitative real-time polymerase chain reaction (qRT-PCR) analysis on these 12 genes, ultimately identifying 10 genes responsive to drought stress.

PEG treatment is unsuitable to study root related traits as it alters root anatomy in barley (Hordeum vulgare L.).

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

Transcriptome Regulation Mechanisms Difference between Female and Male Buchloe dactyloides in Response to Drought Stress and Rehydration.

Drought, a pervasive global challenge, significantly hampers plant growth and crop yields, with drought stress being a primary inhibitor. Among resilient species, Buchloe dactyloides, a warm-season and dioecious turfgrass, stands out for its strong drought resistance and minimal maintenance requirements, making it a favored choice in ecological management and landscaping. However, there is limited research on the physiological and molecular differences in drought resistance between male and female B. dactyloides. To decipher the transcriptional regulation dynamics of these sexes in response to drought, RNA-sequencing analysis was conducted using the 'Texoka' cultivar as a model. A 14-day natural drought treatment, followed by a 7-day rewatering period, was applied. Notably, distinct physiological responses emerged between genders during and post-drought, accompanied by a more pronounced differential expression of genes (DEGs) in females compared to males. Further, KEGG and GO enrichment analysis revealed different DEGs enrichment pathways of B. dactyloides in response to drought stress. Analysis of the biosynthesis and signaling transduction pathways showed that drought stress significantly enhanced the biosynthesis and signaling pathway of ABA in both female and male B. dactyloides plants, contrasting with the suppression of IAA and JA pathways. Also, we discovered BdMPK8-like as a potential enhancer of drought tolerance in yeast, highlighting novel mechanisms. This study demonstrated the physiological and molecular mechanisms differences between male and female B. dactyloides in response to drought stress, providing a theoretical basis for the corresponding application of female and male B. dactyloides. Additionally, it enriches our understanding of drought resistance mechanisms in dioecious plants, opening avenues for future research and genetic improvement.

Overexpression of OsRbohH Enhances Heat and Drought Tolerance through ROS Homeostasis and ABA Mediated Pathways in Rice (Oryza sativa L.).

Respiratory burst oxidase homologs (Rbohs) are the primary producers of reactive oxygen species (ROS), which have been demonstrated to play critical roles in plant responses to abiotic stress. Here, we explored the function of OsRbohH in heat and drought stress tolerance by generating overexpression lines (OsRbohH-OE). OsRbohH was highly induced by various abiotic stress and hormone treatments. Compared to wild-type (WT) controls, OsRbohH-OE plants exhibited enhanced tolerance to heat and drought, as determined by survival rate analyses and total chlorophyll content. Histochemical staining revealed that OsRbohH-OE accumulated less ROS. This is consistent with the observed increase in catalase (CAT) and peroxidase (POD) activities, as well as a reduced electrolyte leakage rate and malondialdehyde (MDA) content. Moreover, OsRbohH-OE exhibited enhanced sensitivity to exogenous abscisic acid (ABA), accompanied by altered expression levels of ABA synthesis and catabolic genes. Further analysis indicated that transgenic lines had lower transcripts of ABA signaling-related genes (OsDREB2A, OsLEA3, OsbZIP66, and OsbZIP72) under heat but higher levels under drought than WT. In conclusion, these results suggest that OsRbohH is a positive regulator of heat and drought tolerance in rice, which is probably performed through OsRbohH-mediated ROS homeostasis and ABA signaling.

The Small Auxin-Up RNA 50 (SAUR50) Gene from Ammopiptanthus nanus Negatively Regulates Drought Tolerance.

Drought stress is a primary abiotic stress that causes significant losses to forestry and agricultural production. Therefore, exploring drought-responsive genes and their regulatory mechanism is crucial for plant molecular breeding for forestry and agriculture production safety. Small auxin-up RNA (SAUR) proteins are essential in plant growth and development but show functional diversity in stress response. In this study, the transcriptome sequencing data of Ammopiptanthus nanus seedlings revealed that the expression of AnSAUR50 was continuously downregulated under drought stress. Hence, the AnSAUR50 gene was cloned and functionally analyzed in drought response. The results showed that the coding sequence of AnSAUR50 was 315 bp in length and encoded 104 amino acids. The AnSAUR50 protein showed high conservation, possessed a SAUR-specific domain, and localized in the nucleus and cell membrane. The heterologous expression of the AnSAUR50 gene enhanced the drought sensitivity of the transgenic Arabidopsis with a lower survival rate, biomass, and higher malondialdehyde content and relative electrolyte leakage. Moreover, transgenic plants showed shorter root lengths and bigger stomatal apertures, resulting in facilitating water loss under drought stress. The study indicates that AnSAUR50 negatively regulates drought tolerance by inhibiting root growth and stomatal closure, which provides insights into the underlying function and regulatory mechanism of SAURs in plant stress response.

Assessing the Impact of Drought Stress on Hemp (Cannabis sativa L.) Fibers.

Drought can significantly impact fiber crop cultivation due to the plants' specific water requirements and their extended vegetative period. The purpose of the research was to examine how drought stress affects the quality and chemical composition of hemp (Cannabis sativa L.) fibers. A three-year pot experiment was conducted in a plant growth facility, using controlled drought stress for hemp plants. Soil moisture levels were maintained at three levels, where 45% field water capacity was the control and 35% and 25% FWC were drought. A comprehensive suite of fiber quality characterization techniques, including linear density measurement, tenacity assessment, Fourier Transform Infrared Spectroscopy (FTIR), and Wide-Angle X-ray Diffraction (WAXD), was employed to evaluate the impact of drought stress on fiber properties. The chemical composition of hemp fibers was thoroughly analyzed, quantifying the content of cellulose, hemicellulose, pectin, and lignin. The findings indicate that drought conditions significantly influence linear density, wax and fat content, as well as the crystallinity of the fibers.

Regulation of drought stress on nutrient cycle and metabolism of rhizosphere microorganisms in desert riparian forest.

Microbial communities in desert riparian forest ecosystems have developed unique adaptive strategies to thrive in harsh habitats shaped by prolonged exposure to abiotic stressors. However, the influence of drought stress on the functional and metabolic characteristics of soil rhizosphere microorganisms remains unknown. Therefore, this study aimed to investigate the effects of drought stress on soil biogeochemistry and metabolism and analyze the relationship between the biogeochemical cycle processes and network of differentially-expressed metabolites. Using metagenomics and metabolomics, this study explored the microbial functional cycle and differential metabolic pathways within desert riparian forests. The predominant biogeochemical cycles in the study area were the Carbon and Nitrogen cycles, comprising 78.90 % of C, N, Phosphorus, Sulfur and Iron cycles. Drought led to increased soil C fixation, reduced C degradation and methane metabolism, weakened denitrification, and decreased N fixation. Furthermore, drought can disrupt iron homeostasis and reduce its absorption. The differential metabolic pathways of drought stress include flavonoid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and starch and sucrose degradation. Network analysis of functional genes and metabolism revealed a pronounced competitive relationship between the C cycle and metabolic network, whereas the Fe cycle and metabolic network promoted each other, optimizing resource utilization. Partial least squares analysis revealed that drought hindered the expression and metabolic processes and functional genes, whereas the rhizosphere environment facilitated metabolic expression and the functional genes. The rhizosphere effect primarily promoted metabolic processes indirectly through soil enzyme activities. The integrated multi-omics analysis further revealed that the effects of drought and the rhizosphere play a predominant role in shaping soil functional potential and the accumulation of metabolites. These insights deepen our comprehension of desert riparian forest ecosystems and offer strong support for the functionality of nutrient cycling and metabolite dynamics.

Nanostructure-assisted drought tolerance in olive trees (Olea europaea L.): the role of Fe2O3-graphitic carbon.

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

Drought-dependent regulation of cell coupling in Arabidopsis leaf epidermis requires plasmodesmata protein NHL12.

The cytoplasms of most plant cells are connected by membrane-lined cell wall channels, the plasmodesmata (PD). Dynamic regulation of sugar, hormone and protein diffusion through PD is essential for plant development and stress responses. Understanding this regulation requires knowledge of factors and mechanisms that control PD permeability through the modulation of callose levels in the cell wall around PD openings. We investigated PD regulation in leaf epidermis cells in relation to drought stress in Arabidopsis thaliana. Upon finding PD-mediated cell wall permeability decreased by drought stress and the hormone ABA, we tested several PD-associated genes with drought-responsive expression for their involvement in this response. Mutants of NHL12 showed relatively low PD permeability that was unaffected by drought or ABA treatment. Overexpression of NHL12 in Nicotiana benthamiana epidermis cells increased PD permeability. Moreover, we show that NHL12 can potentially interact with the callose synthase-regulator NHL3 and we explored the effect of NHL12 abundance and/or lower interface permeability on ABA signaling genes. Our results indicate that NHL12 is a drought-responsive negative regulator of PD callose levels and, thereby, interface permeability. Results are discussed with regard to PD function during drought stress and the regulation of intercellular transport.

Nanobiotechnology-mediated regulation of reactive oxygen species homeostasis under heat and drought stress in plants.

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

Physiological and Molecular Mechanisms of Rice Tolerance to Salt and Drought Stress: Advances and Future Directions.

Rice, a globally important food crop, faces significant challenges due to salt and drought stress. These abiotic stresses severely impact rice growth and yield, manifesting as reduced plant height, decreased tillering, reduced biomass, and poor leaf development. Recent advances in molecular biology and genomics have uncovered key physiological and molecular mechanisms that rice employs to cope with these stresses, including osmotic regulation, ion balance, antioxidant responses, signal transduction, and gene expression regulation. Transcription factors such as DREB, NAC, and bZIP, as well as plant hormones like ABA and GA, have been identified as crucial regulators. Utilizing CRISPR/Cas9 technology for gene editing holds promise for significantly enhancing rice stress tolerance. Future research should integrate multi-omics approaches and smart agriculture technologies to develop rice varieties with enhanced stress resistance, ensuring food security and sustainable agriculture in the face of global environmental changes.

The zinc-finger transcription factor ZFP8 negatively regulates the drought stress response in Arabidopsis thaliana by inhibiting the transcriptional activity of ABF2.

Drought stress limits plant growth and development. To cope with drought stress, abscisic acid (ABA) accumulates in plants. Although ABA-dependent drought tolerance pathways have been widely investigated, the feedback mechanisms and the negative regulatory roles within these pathways remain largely unknown. Here we characterize the roles of a C2H2 transcription factor, ZFP8, whose expression is repressed by ABA in the tolerance of drought stress. ZFP8-overexpressing plants were hyposensitive to ABA and exhibited less dehydration tolerance while ABA or drought-induced marker genes were more highly expressed in zfp8, suggesting that ZFP8 functions as a negative regulator in the ABA-mediated drought response. A transcriptome assay showed that ZFP8 positively regulates gene expression for cellular function and negatively regulates hormone and stress response gene expression. Moreover, we found that ZFP8 can interact with ABF2, one of the basic leucine zipper (bZIP) family transcription factor members, to inhibit its transcription activity. In conclusion, our results demonstrate a novel negative regulation pathway of ZFP8, which contributes to plants' ability to fine-tune their drought responses.

Root Endophyte-Manipulated Alteration in Rhizodeposits Stimulates Claroideoglomus in the Rhizosphere to Enhance Drought Resistance in Peanut.

Drought dramatically affects plant growth and yield. A previous study indicated that endophytic fungus Phomopsis liquidambaris can improve the drought resistance of peanuts, which is related with the root arbuscular mycorrhizal fungi (AMF) community; however, how root endophytes mediate AMF assembly to affect plant drought resistance remains unclear. Here, we explored the mechanism by which endophytic fungus recruits AMF symbiotic partners via rhizodeposits to improve host drought resistance. The results showed that Ph. liquidambaris enhanced peanut drought resistance by enriching the AMF genus Claroideoglomus of the rhizosphere. Furthermore, metabolomic analysis indicated that Ph. liquidambaris significantly promoted isoformononetin and salicylic acid (SA) synthesis in rhizodeposits, which were correlated with the increase in Claroideoglomus abundance following Ph. liquidambaris inoculation. Coinoculation experiments confirmed that isoformononetin and SA could enrich Claroideoglomus etunicatum in the rhizosphere, thereby improving the drought resistance. This study highlights the crucial role of fungal consortia in plant stress resistance.