Severe Drought Conditions Research Articles

Assessing the impact of 2022 extreme drought on the Yangtze River basin using downscaled GRACE/GRACE-FO data obtained by partitioned random forest algorithm

ABSTRACT The Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) data have been widely used to monitor and analyze extreme hydrological events globally. However, their coarse spatial resolution limits their application in small- and medium-scale regions. In this study, we proposed a partitioned random forest downscaling (PRFD) strategy to improve the spatial resolution of GRACE/GRACE-FO data and quantitatively assessed the downscaling performance using a closed-loop simulation experiment. Our enhanced approach improved the spatial resolution of GRACE/GRACE-FO data from 1°to 0.1°, and the downscaled data were used to characterize the 2022 extreme drought in the Yangtze River basin (YRB), with particular on a smaller basin (i.e. the Wu River basin, WRB). Our findings show that the PRFD reduced the root mean square error by 39.29% compared to the traditional over RF downscaling (ORFD), and 27.8% of grid points showed significantly accuracy improvements. The downscaled results provided a more detailed depiction of the 2022 extreme drought in the YRB, allowing for precision identification of drought onset, extent and severity, and a more accurate assessment of the drought impacts in the WRB. The extreme drought originated in the northern WRB, gradually extending southward across the basin, with more severe drought conditions in the north than in the south. High temperatures and low precipitation were primary drives, while elevated high human water use also contributed. This study provides a valuable technique for downscaling GRACE/GRACE-FO data and understanding extreme drought in regional-scale areas.

Restoration treatments enhance tree growth and alter climatic constraints during extreme drought.

The frequency and severity of drought events are predicted to increase due to anthropogenic climate change, with cascading effects across forested ecosystems. Management activities such as forest thinning and prescribed burning, which are often intended to mitigate fire hazard and restore ecosystem processes, may also help promote tree resistance to drought. However, it is unclear whether these treatments remain effective during the most severe drought conditions or whether their impacts differ across environmental gradients. We used tree-ring data from a system of replicated, long-term (>20 years) experiments in the southwestern United States to evaluate the effects of forest restoration treatments (i.e., evidence-based thinning and burning) on annual growth rates (i.e., basal area increment; BAI) of ponderosa pine (Pinus ponderosa), a broadly distributed and heavily managed species in western North America. The study sites were established at the onset of the most extreme drought event in at least 1200 years and span much of the climatic niche of Rocky Mountain ponderosa pine. Across sites, tree-level BAI increased due to treatment, where trees in treated units grew 133.1% faster than trees in paired, untreated units. Likewise, trees in treated units grew an average of 85.6% faster than their pre-treatment baseline levels (1985 to ca. 2000), despite warm, dry conditions in the post-treatment period (ca. 2000-2018). Variation in the local competitive environment promoted variation in BAI, and larger trees were the fastest-growing individuals, irrespective of treatment. Tree thinning and prescribed fire altered the climatic constraints on growth, decreasing the effects of belowground moisture availability and increasing the effects of atmospheric evaporative demand over multi-year timescales. Our results illustrate that restoration treatments can enhance tree-level growth across sites spanning ponderosa pine's climatic niche, even during recent, extreme drought events. However, shifting climatic constraints, combined with predicted increases in evaporative demand in the southwestern United States, suggest that the beneficial effects of such treatments on tree growth may wane over the upcoming decades.

Physiological and molecular insights into the effect of a seaweed biostimulant on enhancing fruit yield and drought tolerance in tomato

Tomato is one of the most widely grown vegetable crops in Europe. This study describes an approach for treating tomato plants with an extract of Ascophyllum nodosum (ANF) prior to a stress event, which prepares the plants at the molecular level to respond more effectively to stress conditions, through a process known as molecular priming. Solanum lycopersicum L. cv. Micro-Tom, a dwarf tomato variety, was pre-treated with ANF via foliar spray during the flowering phase and subsequently subjected to drought conditions. ANF-treated plants exhibited enhanced growth, fruit yield, and stress tolerance under both moderate and severe drought conditions compared to untreated plants. Transcriptomic studies in leaves revealed that the priming treatment preserved the photosynthetic machinery, inducing stress-protective genes involved in ascorbate, peroxidase, GABA, glutathione, and flavanol biosynthesis. Simultaneously, the treatment repressed key senescence-related genes associated with ethylene biosynthesis, as well as several WRKY and NAC transcription factors. Metabolome analysis demonstrated that ANF induces drought tolerance by promoting the accumulation of stress-protective primary and secondary metabolites, such as GABA, proline, maltose, ascorbic acid, quercetin, and biotin, which can act as osmoprotectants and free radical scavengers during drought. Combined transcriptome and metabolome analyses suggest that ANF treatment represses the senescence process, maintains photosynthetic activity, and induces the accumulation of protective metabolites and amino acids, promoting plant survival and growth under drought. Overall, this research provides new insights into the molecular mechanisms underlying biostimulant-based molecular priming and offers a knowledge-based approach for the accurate application of this ANF molecular priming agent to increase crop productivity and mitigate yield loss during drought, contributing to food security in the era of climate change.

Future response of ecosystem water use efficiency to CO2 effects in the Yellow River Basin, China

Abstract. Ecosystem water use efficiency (WUE) is pivotal for understanding carbon–water cycle interplay. Current research seldom addresses how WUE might change under future elevated CO2 concentrations, limiting our understanding of regional ecohydrological effects. We present a land–atmosphere attribution framework for WUE in the Yellow River basin (YRB), integrating the Budyko model with global climate models (GCMs) to quantify the impacts of climate and underlying surface changes induced by CO2. Additionally, we further quantitatively decoupled the direct and secondary impacts of CO2 radiative and biogeochemical effects. Attribution results indicate that WUE in the YRB is projected to increase by 0.36–0.84 gC kg−1H2O in the future, with climate change being the predominant factor (relative contribution rate of 77.9 %–101.4 %). However, as carbon emissions intensify, the relative importance of land surface changes becomes increasingly important (respective contribution rates of −1.4 %, 14.9 %, 16.9 %, and 22.1 % in SSP126, SSP245, SSP370, and SSP585). Typically, WUE is considered a reflection of an ecosystem's adaptability to water stress. Thus, we analyzed the response of WUE under different scenarios and periods and various drought conditions. The results show a distinct “two-stage” response pattern of WUE to drought in the YRB, where WUE increases under moderate–severe drought conditions but decreases as drought intensifies across most areas. Furthermore, GCM projections suggest that plant adaptability to water stress may improve under higher-carbon-emission scenarios. Our findings enhance the understanding of regional ecohydrological processes and provide insights for future predictions of drought impacts on terrestrial ecosystems.

Sustainable Land Use Formation Features on Agricultural Land in Kazakhstan

The research aims to analyse the state of agricultural land in the Republic of Kazakhstan with the classification of scientifically based factors affecting the sustainability of land use. This study considers the systems of agricultural land management, noted the pace of development, and forms relationships on land redistribution to increase sustainable land use. It has been established that 80% of the country’s territory consists of agricultural land, of which only 43% is used for its main purpose. The development of livestock and crop production system in conditions of severe drought in 2022 is assessed on the example of climatic conditions of Balkhash district of Almaty region. The practical significance of the work lies in the efficiency of agricultural production, considering all modern technological requirements and finding a dynamic balance between inputs and the corresponding increase in output.

Drought and Salinity Stresses Response in Three Korean Native Herbaceous Plants and Their Suitability as Garden Plants

Native garden plants significantly contribute to the conservation of biodiversity and ecosystem functions in urban environments. This study aimed to identify the physiochemical differences among native herbaceous plants subjected to drought or salinity stress and to assess their potential as garden plants adaptable to outdoor conditions and global climate change. Physiological parameters, such as chlorophyll (SD; −86.7% and −61.5%, SS: −85% and −76.5%) and carotenoid (SD; −84.5% and −58.3%, SS; −80.5% and −76%), decreased in Melica grandiflora and Carex forficula in severe drought or salinity treatment. In contrast, Carex boottiana maintained high water-use efficiency (SD: +97.5%, SS: +262.9%) under severe drought or salinity conditions, with no significant changes observed in chlorophyll (SD: +9.5%, SS: −3.7%) or carotenoid levels (SD: +35.2%, SS: +0.3%) compared to the WW or UT conditions. Biochemical analyses indicated that C. boottiana exhibited lower or slightly higher levels of malondialdehyde in SS (−22.5%) and reactive oxygen species such as O2− (SD: +9.9%; SS: −9.4%) than those observed in the other species under severe stress conditions. Principal component analysis revealed clear differences in tolerance levels among the native species. C. boottiana demonstrated high adaptability to both drought and salinity stress, indicating its potential as a sustainable and resilient garden material for urban landscapes facing severe climatic challenges.

Past Groundwater Drought in the North American Cordillera

AbstractGroundwater level records in North America are relatively short (<60 years), preventing long‐term analysis of historical changes in groundwater levels associated with drought. In this study, tree ring widths are used to reconstruct groundwater levels in three regions in the North American Cordillera: Central British Columbia (BC), Canada, the Southern Interior Region of BC, and the San Luis Valley in Colorado, USA. Periods with severe drought conditions, identified using regime shift and threshold analyses were: 1890–1900 and 1950–1970 in Colorado, around 1920–1940 in the BC Interior, and 1935–1945 in Central BC. The groundwater level reconstructions are correlated with several climate indices and have similar regime shifts as identified in streamflow and drought records. The groundwater level reconstructions are strongly related to winter snowpack, suggesting that the observed trend of declining snowpack in recent years may lead to declining groundwater availability in these regions.

An Innovative TOPSIS–Mahalanobis Distance Approach to Comprehensive Spatial Prioritization Based on Multi-Dimensional Drought Indicators

This research explores a new methodological framework that blends the TOPSIS (technique for order of preference by similarity to ideal solution) and Mahalanobis Distance methods, allowing for the prioritization of nine major watersheds in China based on the integration of multi-dimensional drought indicators. This integrated approach offers a robust prioritization model by accounting for spatial dependencies between indices, a feature not commonly addressed in traditional multi-criteria decision-making applications in drought studies. This study utilized three drought indices—the Standardized Precipitation Evapotranspiration Index (SPEI), Vegetation Health Index (VHI), and Palmer Drought Severity Index (PDSI). Over years of significant drought prevalence, three types of droughts occurred simultaneously across various watersheds in multiple years, particularly in 2001, 2002, 2006, and 2009, with respective counts of 16, 17, 19, and 18 concurrent episodes. The weights derived from Shannon’s entropy emphasize the importance of the Potential Drought Severity Index (PDSI) in evaluating drought conditions, with PDSI-D (drought duration) assigned the highest weight of 0.267, closely followed by VHI-D (Vegetation Health Index under drought conditions) at 0.232 and SPEI-F (drought frequency) at 0.183. The results demonstrated considerable spatial variability in drought conditions across the watersheds, with Watersheds 1 and 4 exhibiting the highest drought vulnerability in terms of meteorological and agricultural droughts, while Watersheds 6 and 3 showed significant resilience to hydrological drought after 2012. In particular, the severe meteorological drought conditions at Watershed 1 highlight the urgent need for rainwater harvesting and strict water use policies, and in contrast, the conditions at Watershed 4 show the need for the modernization of irrigation to mitigate agricultural drought impacts. This integrated framework allows for targeted drought management solutions that directly relate to the specific contexts of the watersheds, while being more conducive to planning and prioritizing resource allocations for regions facing the highest drought vulnerability.

Unlocking Wheat Drought Tolerance: The Synergy of Omics Data and Computational Intelligence

ABSTRACTCurrently, approximately 4.5 billion people in developing countries consider bread wheat (Triticum aestivum L.) as a staple food crop, as it is a key source of daily calories. Wheat is, therefore, ranked the second most important grain crop in the developing world. Climate change associated with severe drought conditions and rising global mean temperatures has resulted in sporadic soil water shortage causing severe yield loss in wheat. While drought responses in wheat crosscut all omics levels, our understanding of water‐deficit response mechanisms, particularly in the context of wheat, remains incomplete. This understanding can be significantly advanced with the aid of computational intelligence, more often referred to as artificial intelligence (AI) models, especially those leveraging machine learning and deep learning tools. However, there is an imminent and continuous need for omics and AI integration. Yet, a foundational step to this integration is the clear contextualization of drought—a task that has long posed challenges for the scientific community, including plant breeders. Nonetheless, literature indicates significant progress in all omics fields, with large amounts of potentially informative omics data being produced daily. Despite this, it remains questionable whether the reported big datasets have met food security expectations, as translating omics data into pre‐breeding initiatives remains a challenge, which is likely due to data accessibility or reproducibility issues, as interpreting omics data poses big challenges to plant breeders. This review, therefore, focuses on these omics perspectives and explores how AI might act as an interface to make this data more insightful. We examine this in the context of drought stress, with a focus on wheat.

Transcriptional analysis of maize elite inbred line Jing24 and the function of ZmMAPKKK21 in the response to drought stress

Drought, one of the most devastating abiotic stresses to affect agricultural production worldwide, causes significant crop yield loss. In China, the yield and value of maize, a drought-sensitive staple crop, is significantly affected by drought. Jing24 (J24) is an elite, robust, and drought-resistant maize inbred line, but the underlying genetic basis for this resistance is imperfectly understood. We characterized the overall performance of three maize varieties (J24, B73, and X178) under moderate and severe drought conditions at seedling and flowering stages. RNA-Seq analysis revealed more genes to respond to drought treatment in J24 than either B73 or X178, and that some drought-responsive genes were common to each line in leaf and root tissues. Gene ontology analysis of common differentially expressed genes in J24 and X178 revealed membrane and transporter related genes to be significantly enriched in roots, whereas genes associated with photosynthesis and membrane were most-enriched in leaves. Because expression of ZmMAPKKK21 was significantly up-regulated in the root of J24 in the moderate drought treatment, we obtained transgenic Arabidopsis plants overexpressing ZmMAPKKK21 that showed a substantial reduction in ABA sensitivity but increase in drought tolerance. Maize plants in which ZmMAPKKK21 was knocked out were more sensitive to water deficiency and have a smaller root system and a lower survival rate after rewatering than wild type plants. These results suggest that ZmMAPKKK21 is a positive regulator for drought response in J24, which provides insights into the molecular mechanism of the strong drought resistance of J24.

Metarhizium anisopliae (MetA1) seed priming improves photosynthesis, growth, plant defense and yield of wheat under drought stress

Drought stress mitigation by endophytic microorganisms has the potential to enhance crop resilience. This research investigated the effects of M. anisopliae isolate MetA1 (MA) on drought tolerance in wheat plants by evaluating physiological, morphological, biochemical, and yield characteristics of two wheat genotypes, one being drought-susceptible (BR20) and another having drought withstanding capacities (BR28) in a pot experiment under moderate and severe drought conditions. Under drought conditions, root colonization by M. anisopliae ranged from 33.33 to 66.67%. M. anisopliae treated plants increased the plant photosynthetic capacities by increasing photosynthetic pigments, Phi2, gH+, vH+, LEF, ECSt, leaf thickness and decreasing PhiNO, PhiNPQ, NPQt and leaf angle mostly for both genotypes, which contributed significant improvement of plant biomass in drought conditions. Exceptionally, the seed primed with M. anisopliae noticeably improved root length (by up to 17.6%) under drought conditions corroborated with the plant's drought mitigating approach. The stress induced malondialdehyde and hydrogen peroxide levels were dropped significantly by improving enzymatic antioxidants, such as peroxidase, ascorbate peroxidase, superoxide dismutase, catalase, and glutathione S-transferase in both M. anisopliae -primed genotypes. Also, proline content increased in the leaves of M. anisopliae treated plant which indicates better osmotic adjustment. Finally, M. anisopliae seed priming increased yield and yield characteristics of both genotypes in drought as well as non-drought situations with 1000-grain weight improving by up to 41.77% under severe drought. The study proposes a further investigation of M. anisopliae's effect in field settings and its applicability to other crops. Collectively, these findings emphasize the practical potential of M. anisopliae seed priming in boosting wheat production under water-limited circumstances, presenting a realistic technique for minimizing the effect of drought on global food security.

Drought-Induced Alterations in Carbon and Water Dynamics of Chinese Fir Plantations at the Trunk Wood Stage.

Over the past three decades, China has implemented extensive reforestation programs, primarily utilizing Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) in southern China, to mitigate greenhouse gas emissions and counter extreme climate events. However, the effects of drought on the carbon sequestration capacity of these forests, particularly during the trunk wood stage, remain unclear. This study, conducted in Huitong, Hunan, China, from 2008 to 2013, employed the eddy covariance method to measure carbon dioxide (CO2) and water fluxes in Chinese fir forests, covering a severe drought year in 2011. The purpose was to elucidate the dynamics of carbon and water fluxes during a drought year and across multi-normal year averages. The results showed that changes in soil water content (-8.00%), precipitation (-18.45%), and relative humidity (-5.10%), decreases in air temperature (-0.09 °C) and soil temperature (-0.79 °C), and increases in vapor pressure deficit (19.18%) and net radiation (8.39%) were found in the drought year compared to the normal years. These changes in environmental factors led to considerable decreases in net ecosystem exchange (-40.00%), ecosystem respiration (-13.09%), and gross ecosystem productivity (-18.52%), evapotranspiration (-12.50%), and water use efficiency (-5.83%) in the studied forests in the drought year. In this study, the occurrence of seasonal drought due to uneven precipitation distribution led to a decrease in gross ecosystem productivity (GEP) and evapotranspiration (ET). However, the impact of drought on GEP was greater than its effect on ET, resulting in a reduced water use efficiency (WUE). This study emphasized the crucial role of water availability in determining forest productivity and suggested the need for adjusting vegetation management strategies under severe drought conditions. Our results contributed to improving management practices for Chinese fir plantations in response to changing climate conditions.

Examine the Role of Indo-Pacific Sea Surface Temperatures in Recent Meteorological Drought in Sudan

Drought poses a serious threat to Sudan, causing water shortages, crop failures, hunger, and conflict. The relationships between Indo-Pacific teleconnections and drought events in Sudan are examined based on the Standardized Precipitation Index (SPI), anomalies, Empirical Orthogonal Function (EOF), correlation, composite analysis, sequential Mann–Kendall test, and MK-trend test during the period of 1993–2022. The results of the SPI-1 values indicate that the extreme drought in Sudan in 2004 was an exceptional case that affected the entire region, with an SPI-1 value of −2 indicating extremely dry conditions. In addition, Sudan experienced moderate to severe drought conditions for several years (1993, 2002, 2008, 2009 and 2015). The Empirical Orthogonal Function showed that the first EOF mode (42.2%) was the dominant variability mode and had positive loading over most of the country, indicating consistent rainfall variation in the central, eastern, and western regions. Correlation analysis showed a strong significant relationship between June–September rainfall and Indian Ocean sea surface temperature (SST) (r ≤ 0.5). Furthermore, a weak positive influence of the Indian Ocean Dipole (IOD) on JJAS precipitation was observed (r ≤ 0.14). Various time lags in the range of ±12 months were examined, with the highest correlation (0.6) found at 9 month among the time lags of ±12 months. This study contributes to a better understanding of drought dynamics and provides essential information for effective drought management in Sudan. Further research is needed to explore the specific mechanisms driving these interactions and to develop tailored strategies to mitigate the impacts of drought events in the future.

Physio-biochemical mechanism of melatonin seed priming in stimulating growth and drought tolerance in bread wheat

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.

The flash droughts across the south-central United States in 2022: Drivers, predictability, and impacts

A rare subseasonal-to-seasonal phenomenon – two consecutive flash drought events interrupted by a period of recovery – occurred across eastern Oklahoma, Arkansas, and southern Missouri, spanning the summer and early fall of 2022. These flash drought events (the first in June–July, the second in August–September) led to severe (D2) and extreme (D3) drought conditions via the United States Drought Monitor across much of the region following the first period of rapid drought intensification, and extreme (D3) and exceptional (D4) drought conditions by the end of the second event. A notable driver of both flash drought events included a persistent upper-level ridge either centered over or shifted west and upstream of the flash drought region, leading to broad-scale subsidence and reduced mid-level moisture which acted to limit precipitation development and increase evaporative demand. In addition, several heatwave events developed during the warm season in 2022 and either (1) acted to drive flash drought development via increased evaporative demand or (2) were enhanced by land surface desiccation and land-atmosphere feedbacks following rapid drought intensification. Furthermore, S2S composite forecasts predicted drought development for both events. However, only 20% of the ensembles predicted rapid drought development associated with flash drought for the first event and 16% of the ensembles predicted rapid drought development during the second event. This result highlights a key challenge in S2S prediction of rapidly developing drought conditions versus that of more conventional and slower drought development. The ensembles that did predict rapid drought intensification were associated with the forecasting of positive 500 hPa geopotential height anomalies over the south-central United States (first event) or an amplified wave pattern centered over the west-central United States (second event). Lastly, the compounding effects of two flash droughts in a single warm season led to substantial impacts on agricultural, environmental, and hydrologic sectors across the region.

Satellite observations indicate that chia uses less water than other crops in warm climates

Many parts of the world face severe and prolonged drought conditions, stressing the sustainability of water resources and agriculture. Transitioning to water-efficient crops is one strategy that can help adapt to water scarcity. An emerging drought-tolerant crop of interest is chia (Salvia hispanica). Yet, no study has compared its large-scale water use dynamics to those of widely established crops across the globe. Here, we use satellite data over multiple years to assess the water use efficiency of chia, alfalfa, corn, and soybean globally. Results show that chia consumed 13-38% less water than alfalfa, corn, and soy and assimilated 14-20% more carbon per amount of water used. Substituting 10% of Southwest United States alfalfa cultivation with chia would save 184 million liters of water per growing season, equivalent to the annual water consumption of 1,300 households. Future research shall explore the economic, societal, and environmental ramifications of substituting alfalfa with chia in dry areas worldwide. These insights can guide decision-makers in promoting sustainable agriculture and water resource management.

Genotype-specific morphophysiological adaptations and proline accumulation uncover drought adaptation complexity in hemp (Cannabis sativa and Cannabis indica)

Hemp, which has a wide range of industrial applications, has been marginalized due to its association with marijuana. This stigma has hindered research into improving its resilience to various stressors, resulting in underutilization and neglect. As cultivation expands globally, particularly in hot, dry regions of Africa, understanding drought stress mechanisms in hemp is crucial. This study investigates the drought adaptation mechanisms of three CBD flower hemp genotypes: Cannabis indica (MP) from Switzerland, Cannabis sativa (AQ) from South Africa, and Cannabis sativa (ZB) from Zimbabwe. Conducted under well-watered (WW-75% field capacity [FC]), mild drought (MD-40% FC), and severe drought (SD-0% FC) conditions, the research examines morphophysiological adaptations and proline accumulation in these genotypes, assessed 55 days after transplanting. Results revealed genotype-specific responses to watering regimes. MP demonstrated controlled water use and inherent drought tolerance, maintaining high assimilation rates (A) and superior photosynthetic performance (ΦPSII) under drought conditions. ZB maintained proline levels during drought recovery, suggesting optimized resource allocation and alternative stress-responsive mechanisms, while exhibiting effective morning water use and high non-photochemical quenching (NPQ) for photoprotection. AQ showed conservative water use strategies beneficial in water-limited environments. These findings provide a foundation for breeding programs aimed at developing robust and resilient hemp varieties suited to specific environmental conditions.

Moderate alternate wetting and drying irrigation enhances drought-resistance abilities by improving structural mesophyll conductance of water-saving and drought-resistant rice under severe drought.

Water-saving and drought-resistant rice (WDR) coupled with alternate wetting and drying irrigation (AWDI) possesses a high photosynthetic potential due to higher mesophyll conductance (gm) under drought conditions. However, the physiological and structural contributions to the gm of leaves and their mechanisms in WDR under AWDI are still unclear. In this study, WDR (Hanyou 73) and drought-sensitive rice (Huiliangyou 898) were selected as materials. Three irrigation patterns were established from transplanting to the heading stage, including conventional flooding irrigation (W1), moderate AWDI (W2), and severe AWDI (W3). A severe drought with a soil water potential of -50 kPa was applied for a week at the heading stage across all treatments and cultivars. The results revealed that severe drought reduced gas exchange parameters and gm but enhanced antioxidant enzyme activities and malondialdehyde content in the three treatments and both cultivars. The maximal photosynthetic rate (Amax) of HY73 in the W2 treatment was greater than that in the other combinations of cultivars and irrigation patterns. The contribution of leaf structure (54%) to gm (gm-S, structural gm) was higher than that of leaf physiology (46%) to gm (gm-P, physiological gm) in the W2 treatment of Hanyou 73. Additionally, gm-S was significantly and linearly positively correlated with gm under severe drought. Moreover, both the initial and apparent quantum efficiencies were significantly and positively with gm in rice plants (p < 0.05). These results suggest that the improvements in photosynthesis and yield in the WDR combined with moderate AWDI can mainly be attributed to the enhancement of gm-S under severe drought conditions. Quantum efficiency may be a potential factor in regulating photosynthesis by cooperating with the gm of rice plants under severe drought conditions.

Harnessing Virtual Insights: A Computational Study on the Molecular Characterization of a Drought‐Inducible RNA‐Binding Protein for Enhancing Drought Tolerance in Mungbean (Vigna radiata L.)

AbstractAbiotic stresses, particularly drought and salinity, significantly impact agricultural crop yields, with mung bean (Vigna radiata L.) being no exception. This annual green legume, vital to agricultural systems in Asia, is generally resilient to limited water supply; however, severe drought conditions at critical growth stages can drastically diminish both its quality and yield. Drought stress negatively affects various morpho‐physicochemical properties, impeding plant growth and highlighting the need for sustainable approaches to enhance mung bean's drought tolerance through improved farming practices. In this study, we focused on identifying and understanding the molecular mechanisms underlying drought tolerance in mung beans. We retrieved the target gene sequence from the NCBI database, but found no direct sequence similarity, which led to the use of homology modeling. The structure of a known protein (PDB ID: 5T9P) was identified as the most suitable template. Motif prediction using the Motif Search tool highlighted specific motifs relevant to drought stress responses. To investigate potential drought‐tolerance mechanisms, we screened ABA agonists using Density Functional Theory (DFT) analysis. Molecular docking and MD simulations revealed the interactions between these ligands and the modeled protein, shedding light on how they might influence drought tolerance. We performed molecular dynamics (MD) simulations to assess the stability and conformational dynamics of the modeled protein across different time scales. Our findings underscore the potential of ABA agonists to modulate physiological responses and enhance drought resistance. This research offers valuable insights into the conformational dynamics of drought‐related proteins in mung beans, elucidating the molecular underpinnings of drought response mechanisms. By advancing our understanding of these processes, our findings provide novel strategies for improving breeding approaches aimed at enhancing crop resilience against water scarcity and other abiotic stresses. This work promises to mitigate the detrimental effects of drought on mung bean yields and supports sustainable agricultural practices, thereby contributing to global food security.

Utilizing the vegetation health index to assess agricultural drought in the Constantine Region of Algeria

This research employs remote sensing techniques to map agricultural drought in the Constantine region of Algeria during the years 2021 to 2023. Using Landsat images processed through the Google Earth Engine platform, three indices (NDVI, VHI, and SPI) were calculated. The findings indicate deterioration in both climatic conditions and vegetation health. Specifically, NDVI and SPI exhibit decreases, while VHI shows an increase, signaling heightened water stress. The inverse relationship between NDVI and VHI underscores the connection between water availability and vegetation health. Additionally, a detailed analysis reveals severe drought conditions in the Southwestern part of the region. This study showcases the value of utilizing remote sensing technology on the Google Earth Engine platform for monitoring climate and vegetation patterns over space and time. These insights can help in forecasting the effects of climate change on agriculture and inform the adoption of suitable strategies to ensure food security.