NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 1...NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007.The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part.As a result,relationships between an atmospheric heating source(hereafter called <Q_1>) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper.The results are shown as follows.The flood/drought to the north of Yangtze River(NYR) was mainly related to the <Q_1> over the East Asia summer monsoon region:when the <Q_1> over the Philippines through Western Pacific and the south China was weakened(strengthened),it would probably result in the flood(drought) in NYR;and the precipitation on the south side of Yangtze River(SYR)was related to the <Q_1> over the east Asia and Indian summer monsoon region:when the <Q_1> over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened(weakened),and the <Q_1> over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened(strengthened),it will lead to flood(drought) in SYR.展开更多
By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought duri...By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought during the annually first rainy season in south China. Results show that westem Pacific subtropical high and wind anomalies over the northeast of Lake Baikal and central Indian Ocean are important factors. Wind anomalies over the northem India in January and the northwest Pacific in March may be strong prediction signals. Study also shows that rainfall in south China bears a close relation to the geopotential height filed over the northern Pacific in March.展开更多
In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mit...In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.展开更多
Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance...Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.展开更多
Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food securit...Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food security.This study investi-gates the atmospheric and oceanic mechanisms that modulate JJAS rainfall us-ing composite analysis,probability evaluation of the Z-index,and correlation analysis with leading climate drivers,including sea surface temperatures(SSTs),wind circulation,and outgoing longwave radiation(OLR).The results show that 40.3%of JJAS rainfall is normal,29.5%and 30.2%are dry and wet,respectively.Wet years have sharply increased since 1998,showing a shift in the rainfall patterns.Wind circulation analysis shows that 850 hPa westerly and 200 hPa easterly winds occur during wet years,which enhance the transport of moisture and convection,whereas dry years have their wind patterns in re-verse,suppressing rainfall.The correlation of Sea Surface Temperature with rainfall in JJAS has a very significant negative correlation(-0.8)in central and eastern Pacific SSTs,indicating La Niña enhancing rainfall and El Niño deficit it.Conversely,a significant positive correlation(0.8)in the western Pacific modulating the regional SST anomaly Ethiopian rainfall.The Nino 3.4 Index shows a significant negative relationship(-0.5 to-0.8)with Ethiopia’s JJAS rain,especially in the northeast,central,and eastern regions,the key role of the ENSO in rainfall variability.Moreover,the negative OLR anomaly and high RH,promote cloudiness and precipitation,while dry years are distinguished by the higher OLR anomaly and reduced RH,which suppress convection.These results confirm the leading influence of the El Nino-Southern Oscillation(ENSO)in controlling Ethiopian rainfall variability and suggest that monitor-ing of SST structure,particularly the Nino 3.4 Index,might enhance seasonal rainfall prediction and inform the Ethiopian climatic change strategy.Future studies should incorporate high-resolution modeling,improved observations,advanced statistics,and Machine Learning to better comprehend Ethiopia’s cli-mate extremes.展开更多
Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant va...Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant varieties is a sustainable strategy to mitigate drought,therefore,reliable evaluation systems are essential to identify drought-resistant pepper accessions.In this study,100 pepper accessions were screened for drought resistance under highly controlled conditions at the vegetative stage.Selected accessions exhibited a significantly higher recovery rate after water-deficiency and showed durable resistance under greenhouse conditions.Correlation analysis between drought resistance with morphological and physiological traits showed that the recovery rate was positively correlated with root length and relative water content,and negatively correlated with plant height and leaf area.Gene expression analysis showed that the drought-resistant accession exhibited higher expression levels of drought-responsive genes under drought stress.Among the accessions,anthocyanin-accumulating peppers showed more significant drought resistance compared to other accessions.When the MYB transcription factor An2,the genetic determinant of anthocyanin accumulation,was silenced,drought resistance was significantly reduced.Drought-resistant accessions with favorable adaptive traits identified in this study will be valuable in various breeding programs to generate new pepper cultivars to cope with climate change.展开更多
The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought ...The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.展开更多
Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of ...Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.展开更多
Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea...Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.展开更多
Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradat...Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradation represents a promising strategy for developing drought-tolerant wheat genotypes.This study evaluates the performance of the photosynthetic apparatus in transgenic wheat line with RNAi-mediated suppression of proline dehydrogenase(ProDH)and in the original(wild-type)genotype,under both drought and recovery conditions.Drought was induced at the flowering stage by lowering soil moisture to 30%field capacity for 7 days,compared with 70%field capacity in control plants.Measurements were taken at the onset and end of drought period and 7 days after subsequent recovery.The results demonstrated that drought-treated transgenic plants exhibited improved responses to both the short-term and prolonged effects of stress.Relative water content and chlorophyll levels in the leaves of the transgenic plants changed to a significantly lesser extent.The CO2 assimilation rate in the leaves of transgenic plants was significantly higher than in the wild type under both drought stress and recovery.The transgenic plants also showed superior water-use efficiency during photosynthesis under both conditions.While superoxide dismutase and ascorbate peroxidase activities in leaf chloroplasts increased similarly in both genotypes under drought,they returned to control levels more rapidly in the transgenic plants during recovery.Drought-induced productivity reduction was also significantly lower in the transgenic plants.These findings suggest that RNAi-mediated suppression of ProDH improved photosynthetic performance and grain yield in wheat under drought conditions.展开更多
Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and...Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and agronomy and drought tolerance.The present study identified structural chromosome variations(SCVs)in a doubled haploid(DH)population and backcross introgression lines(BC5F3)derived from Jinmai 47 and Jinmai 84 using fluorescence in situ hybridization(FISH).There are one simple translocation,10 present/absent variations(PAVs),and one copy number variation(CNV)between Jinmai 47 and Jinmai 84,which distributed in 10 chromosomes.Eight SCVs were associated with 15 agronomic traits.A PAV recombination occurred on chromosome 2A,which was associated with grain number per spike(GNS).The 1BL/1RS translocation and PAV.2D were associated with significant reductions in plant height,deriving from the effects on LI2-LI4,LI2-LI4 and UI,respectively respectively.PAV.2D was also contributed to an increase of 3.13%for GNS,1BL/1RS significantly increased spikelet number,grain length(GL),and grain thickness(GT).The effect of PAV.4A.1 on GL,PAV.6A on spike length(SL)and thousand-grain weight(TGW),PAV.6B on SL,GT and TGW were identified and verified.PAVs on chromosomes 2A,6A,1D,2D,and a CNV on chromosome 4B were associated with the drought tolerance coefficients.Additive and interaction effects among SCVs were observed.Many previously cloned key genes and yield-related QTL were found in polymorphic regions of PAV.2B,PAV.2D,and CNV.4B.Altogether,this study confirmed the genetic effect of SCVs on agronomy and drought tolerance,and identification of these SCVs will facilitate genetic improvement of wheat through marker-assisted selection.展开更多
Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of F...Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of FDs in Inner Mongolia,China,and to assess the roles of key meteorological drivers in driving soil moisture variability,FD events were identified using root-zone soil moisture data during the growing seasons from 1982 to 2022.The results indicate the presence of five FD hotspot regions,located in the southern Alxa Plateau,the Hetao Plain in Bayannur,the northwestern Xilingol Plain,the western Liaohe River Plain,and the northern Da Hinggan Ling.Over 41 years,FDs occurred on average 7.44 events across the study area,with a mean duration of 9.17 pentads(1 pentad equals 5 days).The duration exhibited a significant increasing trend of 0.39 pentads/10 years.FD onsets primarily lasted for 2-3 pentads.During the FD development phase,precipitation and evapotranspiration decreased while temperature,potential evapotranspiration,incoming solar radiation,and vapor pressure deficit increased.The dominant meteorological drivers of FD development exhibited notable spatial heterogeneity across hotspot regions,and vapor pressure deficit consistently was the most influential factor.These findings improve the understanding of climate drivers at different stages of FD development and provide scientific support for early warning and prevention of droughts in Inner Mongolia.展开更多
Finger millet(Eleusine coracana Gaertn.),a nutritionally rich and drought-resilient C4 cereal,possesses exceptional grain storage longevity(up to 50 years).Here,we report a high-quality genome assembly of the allotetr...Finger millet(Eleusine coracana Gaertn.),a nutritionally rich and drought-resilient C4 cereal,possesses exceptional grain storage longevity(up to 50 years).Here,we report a high-quality genome assembly of the allotetraploid cultivar C142,revealing extensive structural rearrangements between its two subgenomes(subA and subB),which are associated with asymmetric gene expression and subgenome dominance favoring subA.SubB diverged from subA and E.indica approximately 6.8 million years ago.Subsequently,two whole-genome duplication events shaped the current genome architecture,contributing to gene redundancy and adaptive potential.Notably,expansion of stress-related gene families,such as aldo-keto reductases,suggests a role in oxidative stress response and drought adaptation.Using genome-wide association studies,we identify several candidate genes associated with key agronomic traits.Among them,EcMDHAR,encoding monodehydroascorbate reductase,plays a critical role in enhancing drought tolerance.Different EcMDHAR haplotypes exhibit distinct expression profiles,supporting their functional relevance in drought adaptation.This genomic resource not only advances our understanding of polyploid genome evolution in millets,but also provides a foundation for genome-assisted improvement of drought resistance and nutritional quality in finger millet.展开更多
Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of P...Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of Picea crass ifolia(Qinghai spruce)during the growing seasons of2021-2023 under intensifying drought at three altitudes in Qilian Mountains,Northwest China.Our results revealed synchronous seasonal patterns in soluble sugar,starch,and total non-structural carbohydrate within the same year,contrasting with marked altitudinal disparities.As drought progressed(from 2021 to 2023),soluble sugars initially increased(2022)then declined(2023),while starch showed consistent reduction(except leaves).Moreover,the altitude of peak NSCs concentrations shifted from 3200 m in 2021to 2700 m in 2023.In particular,prolonged drought alters the environmental factors affecting NSCs.NSCs demonstrated significant positive correlations with soil temperature during humid 2021,then negatively with air temperature,vapor pressure deficit,and precipitation during 2022's initial drought,whereas under 2023's persistent drought conditions,soil temperature and water content emerged as dominant drivers.Concurrently,the ratio of soluble sugar to starch transitioned from air temperature and precipitation associations(2021-2022)to soil parameter dependence in2023.These findings provide new insights into the seasonal carbon dynamics of Qinghai spruce and the environmental response mechanisms under increasing drought stress,contributing to a better understanding of tree physiological adaptations in drought stress.展开更多
Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding ...Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding stress,exploring both the methodology and physiological mechanisms involved.The optimal seed soaking concentration was determined through a gradient experiment,followed by a multi-cultivar validation test.The physiological mechanism of wood vinegar soaking on seedling emergence was analyzed by measuring the electrical conductivity of the flooding water,the changes in starch and soluble sugar contents in the grains and sprouts,and the dynamics ofα-amylase activity and antioxidant-related enzyme activities in the sprouts.The results showed that soaking rice seeds in a wood vinegar solution at a low concentration significantly enhanced the emergence of rice seedlings under flooding conditions,with a 100-fold dilution having the most pronounced effect,increasing seedling rates by 50.6%-60.0%.Further analysis indicated that wood vinegar treatment enhanced seedling establishment by inducing a significant increase inα-amylase activity,leading to a 74.9%-213.6%increase in soluble sugar content in the sprouts during 2-8 d after flooding stress compared with the control.Additionally,the treatment increased superoxide dismutase and peroxidase activities in the sprouts,mitigating lipid peroxidation of the cell membranes,and notably lower water electrical conductivity was observed in wood vinegar-treated seeds compared with the control.In conclusion,soaking rice seeds in a 100-fold diluted wood vinegar solution improves rice seedling rates under flooding stress by mitigating oxidative damage and maintaining energy supply.This approach is valuable for developing cost-effective seed treatment technologies and offering novel strategies to improve seedling rates and uniformity of direct-seeded rice under flooding conditions.展开更多
Satellite hydrology has reached a new era where a variety of earth observing systems,in conjunction with the development of data integrations,can provide a consistent monitoring of groundwater change,wetland dynamics,...Satellite hydrology has reached a new era where a variety of earth observing systems,in conjunction with the development of data integrations,can provide a consistent monitoring of groundwater change,wetland dynamics,and drought evolution in regions where observations on the ground remain sparse or patchy.This synthesis review highlights the physical observables that are most useful to terrestrial hydrology:variable time-dependent gravity,passive and active microwave signals,optical reflectance,thermal infrared measurements,and altimetry,and this has been translated into hydrologic states and water fluxes:terrestrial water storage,ground water storage anomalies,inundation extent and hydroperiod,evapotranspiration,and multi-timescale drought indicators.We call attention to the role of satellite gravimetry in the transformation of basin-scale groundwater evaluation,synthetic aperture radar(SAR),and optical time series in transforming wetland science,however,to the characterization of hydroperiod and connectivity.In the case of drought,we recommend the use of both fast-responsive(soil moisture,evapotranspiration,thermal stress,and vegetation condition)in conjunction with slowly integrating storage anomalies to detect onset,intensification,and recovery,as well as rely on to diagnose the spread of deficits through the hydrologic system.In all these themes,we recognize the central action of enabling approaches that include multi-sensor fusion,data assimilation,and hybrid machine learning schemes in reducing ambiguity,scale gaps,and producing products of decision interest,and also highlighting ongoing issues in the quantification of uncertainty,consistency across long periods of time,and the separation of climate influence on human management of water.Research and operational priorities come as our final deduction to develop satellite hydrology to more trustworthy,explanation-seeking,and operationalizing monitoring designs of water security and ecosystem resilience.展开更多
Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promis...Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promise in augmenting cultivated apple resistance to abiotic stress.Although Alfin-like(ALs)proteins have demonstrated pivotal roles in dicotyledonous plants'response to abiotic stresses,knowledge about AL genes in apple rootstocks is limited,and their functions remain largely elusive.In this study,we identified and characterized 10 MpAL gene members in the apple rootstock genome,confirming their localization within the nucleus.Our investigation revealed the significant regulation of MpALs'expression under drought and abscisic acid(ABA)stresses in M.prunifolia.In this study,one of the members,MpAL1,was selected for further exploration in Arabidopsis and apple to explore its potential function in response to drought and ABA stresses.The results showed that overexpression-MpAL1 transgenic apple calli grew significantly better than WT and MpAL1-RNAi lines,which regulates the accumulation of H_(2)O_(2)and O_(2).-levels.Additionally,transgenic Arabidopsis plants overexpressing MpAL1 exhibited positively regulating antioxidant enzymes activities under stress treatments.Further study showed that silencing MpAL1 in apple plants showed obvious chlorosis in leaves,and accumulation of reactive oxygen species under drought stress.Moreover,our detailed analysis established that MpAL1 regulates several drought and ABA-responsive genes,exerting an influence on their expression in transgenic apple.Collectively,our findings identify MpAL1 as a positive regulator that increases drought stress in apple,shedding light on its potential significance in bolstering drought resistance in this fruit crop.展开更多
Accurate prediction of flood events is important for flood control and risk management.Machine learning techniques contributed greatly to advances in flood predictions,and existing studies mainly focused on predicting...Accurate prediction of flood events is important for flood control and risk management.Machine learning techniques contributed greatly to advances in flood predictions,and existing studies mainly focused on predicting flood resource variables using single or hybrid machine learning techniques.However,class-based flood predictions have rarely been investigated,which can aid in quickly diagnosing comprehensive flood characteristics and proposing targeted management strategies.This study proposed a prediction approach of flood regime metrics and event classes coupling machine learning algorithms with clustering-deduced membership degrees.Five algorithms were adopted for this exploration.Results showed that the class membership degrees accurately determined event classes with class hit rates up to 100%,compared with the four classes clustered from nine regime metrics.The nonlinear algorithms(Multiple Linear Regression,Random Forest,and least squares-Support Vector Machine)outperformed the linear techniques(Multiple Linear Regression and Stepwise Regression)in predicting flood regime metrics.The proposed approach well predicted flood event classes with average class hit rates of 66.0%-85.4%and 47.2%-76.0%in calibration and validation periods,respectively,particularly for the slow and late flood events.The predictive capability of the proposed prediction approach for flood regime metrics and classes was considerably stronger than that of hydrological modeling approach.展开更多
基金National Natural Science Foundation of China(41275080)China Meteorological Administration Special Public Welfare Research Fund(GYHY201306022)Open Research Fund Program of Plateau Atmosphere and Environment Key Laboratory of Sichuan Province(PAEKL-2010-C3)
文摘NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007.The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part.As a result,relationships between an atmospheric heating source(hereafter called <Q_1>) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper.The results are shown as follows.The flood/drought to the north of Yangtze River(NYR) was mainly related to the <Q_1> over the East Asia summer monsoon region:when the <Q_1> over the Philippines through Western Pacific and the south China was weakened(strengthened),it would probably result in the flood(drought) in NYR;and the precipitation on the south side of Yangtze River(SYR)was related to the <Q_1> over the east Asia and Indian summer monsoon region:when the <Q_1> over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened(weakened),and the <Q_1> over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened(strengthened),it will lead to flood(drought) in SYR.
基金Natural Science Foundation of China (40275028)Research Fund for the Science of Tropicaland Marine Meteorology
文摘By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought during the annually first rainy season in south China. Results show that westem Pacific subtropical high and wind anomalies over the northeast of Lake Baikal and central Indian Ocean are important factors. Wind anomalies over the northem India in January and the northwest Pacific in March may be strong prediction signals. Study also shows that rainfall in south China bears a close relation to the geopotential height filed over the northern Pacific in March.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3209800)the National Natural Science Foundation of China(Grant No.52279011).
文摘In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.
文摘Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.
文摘Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food security.This study investi-gates the atmospheric and oceanic mechanisms that modulate JJAS rainfall us-ing composite analysis,probability evaluation of the Z-index,and correlation analysis with leading climate drivers,including sea surface temperatures(SSTs),wind circulation,and outgoing longwave radiation(OLR).The results show that 40.3%of JJAS rainfall is normal,29.5%and 30.2%are dry and wet,respectively.Wet years have sharply increased since 1998,showing a shift in the rainfall patterns.Wind circulation analysis shows that 850 hPa westerly and 200 hPa easterly winds occur during wet years,which enhance the transport of moisture and convection,whereas dry years have their wind patterns in re-verse,suppressing rainfall.The correlation of Sea Surface Temperature with rainfall in JJAS has a very significant negative correlation(-0.8)in central and eastern Pacific SSTs,indicating La Niña enhancing rainfall and El Niño deficit it.Conversely,a significant positive correlation(0.8)in the western Pacific modulating the regional SST anomaly Ethiopian rainfall.The Nino 3.4 Index shows a significant negative relationship(-0.5 to-0.8)with Ethiopia’s JJAS rain,especially in the northeast,central,and eastern regions,the key role of the ENSO in rainfall variability.Moreover,the negative OLR anomaly and high RH,promote cloudiness and precipitation,while dry years are distinguished by the higher OLR anomaly and reduced RH,which suppress convection.These results confirm the leading influence of the El Nino-Southern Oscillation(ENSO)in controlling Ethiopian rainfall variability and suggest that monitor-ing of SST structure,particularly the Nino 3.4 Index,might enhance seasonal rainfall prediction and inform the Ethiopian climatic change strategy.Future studies should incorporate high-resolution modeling,improved observations,advanced statistics,and Machine Learning to better comprehend Ethiopia’s cli-mate extremes.
基金supported by Cooperative Research Program for Agriculture Science and Technology Development(Grant No.RS-2020-RD009069)Rural Development Administration and the National Research Foundation of Korea(Grant No.RS-2021-NR059647),Republic of Korea.
文摘Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant varieties is a sustainable strategy to mitigate drought,therefore,reliable evaluation systems are essential to identify drought-resistant pepper accessions.In this study,100 pepper accessions were screened for drought resistance under highly controlled conditions at the vegetative stage.Selected accessions exhibited a significantly higher recovery rate after water-deficiency and showed durable resistance under greenhouse conditions.Correlation analysis between drought resistance with morphological and physiological traits showed that the recovery rate was positively correlated with root length and relative water content,and negatively correlated with plant height and leaf area.Gene expression analysis showed that the drought-resistant accession exhibited higher expression levels of drought-responsive genes under drought stress.Among the accessions,anthocyanin-accumulating peppers showed more significant drought resistance compared to other accessions.When the MYB transcription factor An2,the genetic determinant of anthocyanin accumulation,was silenced,drought resistance was significantly reduced.Drought-resistant accessions with favorable adaptive traits identified in this study will be valuable in various breeding programs to generate new pepper cultivars to cope with climate change.
基金supported by the National Key R&D Program of China(2021YFD2200303)the National Natural Science Foundation of China(32271903,U24A20428)。
文摘The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.
基金financially supported by the National Key Research and Development Program of China(2021YFD2200405)the National Natural Science Foundation of China(31930078)special funds for Baotianman Forest Ecosystem Research Station from Chinese Academy of Forestry and Ministry of Science and Technology of China。
文摘Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.
基金supported by the Rural Revitalization Tea Industry Technical Service Project of Fujian Agriculture and Forestry University(Grant No.11899170145)the“Double firstclass”scientific and technological innovation capacity and enhancement cultivation plan of Fujian Agriculture and Forestry University(Grant No.KSYLP004)+4 种基金6.18 Tea Industry Technology Branch of Collaborative Innovation Institute(Grant No.K1520001A)Fujian Agriculture and Forestry University Construction Project for Technological Innovation and Service System of Tea Industry Chain(Grant No.K1520005A01)Tea Industry Branch of Collaborative Innovation Institute of Fujian Agriculture and Forestry University(Grant No.K1521015A)Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(Grant No.KFb22020XA)the Special Fund for Science and Technology Innovation of Fujian Zhang Tianfu Tea Development Foundation(Grant No.FJZTF01).
文摘Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.
基金The present study was conducted within the framework of the state budget research topic“Development of the scientific principles of creating high-productive varieties of cultivated plants with increased adaptive potential to adverse environmental conditions”No.6541030 funded by the National Academy of Sciences of Ukraine.
文摘Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradation represents a promising strategy for developing drought-tolerant wheat genotypes.This study evaluates the performance of the photosynthetic apparatus in transgenic wheat line with RNAi-mediated suppression of proline dehydrogenase(ProDH)and in the original(wild-type)genotype,under both drought and recovery conditions.Drought was induced at the flowering stage by lowering soil moisture to 30%field capacity for 7 days,compared with 70%field capacity in control plants.Measurements were taken at the onset and end of drought period and 7 days after subsequent recovery.The results demonstrated that drought-treated transgenic plants exhibited improved responses to both the short-term and prolonged effects of stress.Relative water content and chlorophyll levels in the leaves of the transgenic plants changed to a significantly lesser extent.The CO2 assimilation rate in the leaves of transgenic plants was significantly higher than in the wild type under both drought stress and recovery.The transgenic plants also showed superior water-use efficiency during photosynthesis under both conditions.While superoxide dismutase and ascorbate peroxidase activities in leaf chloroplasts increased similarly in both genotypes under drought,they returned to control levels more rapidly in the transgenic plants during recovery.Drought-induced productivity reduction was also significantly lower in the transgenic plants.These findings suggest that RNAi-mediated suppression of ProDH improved photosynthetic performance and grain yield in wheat under drought conditions.
基金supported by the Science and Technology Major Project of Shanxi Province,China(202201140601025-2,202302140601001)the Agricultural Science Research Project of Shanxi Agricultural University,China(2023BQ108)+1 种基金the Senior Foreign Experts Introducing Project,China(G202204011L)the Science and Technology Innovation Young Talent Team of Shanxi Province,China(202204051001019)。
文摘Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and agronomy and drought tolerance.The present study identified structural chromosome variations(SCVs)in a doubled haploid(DH)population and backcross introgression lines(BC5F3)derived from Jinmai 47 and Jinmai 84 using fluorescence in situ hybridization(FISH).There are one simple translocation,10 present/absent variations(PAVs),and one copy number variation(CNV)between Jinmai 47 and Jinmai 84,which distributed in 10 chromosomes.Eight SCVs were associated with 15 agronomic traits.A PAV recombination occurred on chromosome 2A,which was associated with grain number per spike(GNS).The 1BL/1RS translocation and PAV.2D were associated with significant reductions in plant height,deriving from the effects on LI2-LI4,LI2-LI4 and UI,respectively respectively.PAV.2D was also contributed to an increase of 3.13%for GNS,1BL/1RS significantly increased spikelet number,grain length(GL),and grain thickness(GT).The effect of PAV.4A.1 on GL,PAV.6A on spike length(SL)and thousand-grain weight(TGW),PAV.6B on SL,GT and TGW were identified and verified.PAVs on chromosomes 2A,6A,1D,2D,and a CNV on chromosome 4B were associated with the drought tolerance coefficients.Additive and interaction effects among SCVs were observed.Many previously cloned key genes and yield-related QTL were found in polymorphic regions of PAV.2B,PAV.2D,and CNV.4B.Altogether,this study confirmed the genetic effect of SCVs on agronomy and drought tolerance,and identification of these SCVs will facilitate genetic improvement of wheat through marker-assisted selection.
基金funded by the Inner Mongolia Autonomous Region Natural Science Foundation Youth Fund Project(Grants No.2024QN04020)A Science and technology program of Inner Mongolia Autonomous Region(Grants No.2022YFDZ0027)。
文摘Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of FDs in Inner Mongolia,China,and to assess the roles of key meteorological drivers in driving soil moisture variability,FD events were identified using root-zone soil moisture data during the growing seasons from 1982 to 2022.The results indicate the presence of five FD hotspot regions,located in the southern Alxa Plateau,the Hetao Plain in Bayannur,the northwestern Xilingol Plain,the western Liaohe River Plain,and the northern Da Hinggan Ling.Over 41 years,FDs occurred on average 7.44 events across the study area,with a mean duration of 9.17 pentads(1 pentad equals 5 days).The duration exhibited a significant increasing trend of 0.39 pentads/10 years.FD onsets primarily lasted for 2-3 pentads.During the FD development phase,precipitation and evapotranspiration decreased while temperature,potential evapotranspiration,incoming solar radiation,and vapor pressure deficit increased.The dominant meteorological drivers of FD development exhibited notable spatial heterogeneity across hotspot regions,and vapor pressure deficit consistently was the most influential factor.These findings improve the understanding of climate drivers at different stages of FD development and provide scientific support for early warning and prevention of droughts in Inner Mongolia.
基金supported by the National Crop Germplasm Resources Center(NCGRC-2024-056)the National Natural Science Foundation of China(32301813).
文摘Finger millet(Eleusine coracana Gaertn.),a nutritionally rich and drought-resilient C4 cereal,possesses exceptional grain storage longevity(up to 50 years).Here,we report a high-quality genome assembly of the allotetraploid cultivar C142,revealing extensive structural rearrangements between its two subgenomes(subA and subB),which are associated with asymmetric gene expression and subgenome dominance favoring subA.SubB diverged from subA and E.indica approximately 6.8 million years ago.Subsequently,two whole-genome duplication events shaped the current genome architecture,contributing to gene redundancy and adaptive potential.Notably,expansion of stress-related gene families,such as aldo-keto reductases,suggests a role in oxidative stress response and drought adaptation.Using genome-wide association studies,we identify several candidate genes associated with key agronomic traits.Among them,EcMDHAR,encoding monodehydroascorbate reductase,plays a critical role in enhancing drought tolerance.Different EcMDHAR haplotypes exhibit distinct expression profiles,supporting their functional relevance in drought adaptation.This genomic resource not only advances our understanding of polyploid genome evolution in millets,but also provides a foundation for genome-assisted improvement of drought resistance and nutritional quality in finger millet.
基金supported by the National Natural Science Foundation of China(No.42277481,42007410,32271667,42207537)。
文摘Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of Picea crass ifolia(Qinghai spruce)during the growing seasons of2021-2023 under intensifying drought at three altitudes in Qilian Mountains,Northwest China.Our results revealed synchronous seasonal patterns in soluble sugar,starch,and total non-structural carbohydrate within the same year,contrasting with marked altitudinal disparities.As drought progressed(from 2021 to 2023),soluble sugars initially increased(2022)then declined(2023),while starch showed consistent reduction(except leaves).Moreover,the altitude of peak NSCs concentrations shifted from 3200 m in 2021to 2700 m in 2023.In particular,prolonged drought alters the environmental factors affecting NSCs.NSCs demonstrated significant positive correlations with soil temperature during humid 2021,then negatively with air temperature,vapor pressure deficit,and precipitation during 2022's initial drought,whereas under 2023's persistent drought conditions,soil temperature and water content emerged as dominant drivers.Concurrently,the ratio of soluble sugar to starch transitioned from air temperature and precipitation associations(2021-2022)to soil parameter dependence in2023.These findings provide new insights into the seasonal carbon dynamics of Qinghai spruce and the environmental response mechanisms under increasing drought stress,contributing to a better understanding of tree physiological adaptations in drought stress.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFD2301300)the National Rice Industry Technology System,China(Grant No.CARS-01).
文摘Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding stress,exploring both the methodology and physiological mechanisms involved.The optimal seed soaking concentration was determined through a gradient experiment,followed by a multi-cultivar validation test.The physiological mechanism of wood vinegar soaking on seedling emergence was analyzed by measuring the electrical conductivity of the flooding water,the changes in starch and soluble sugar contents in the grains and sprouts,and the dynamics ofα-amylase activity and antioxidant-related enzyme activities in the sprouts.The results showed that soaking rice seeds in a wood vinegar solution at a low concentration significantly enhanced the emergence of rice seedlings under flooding conditions,with a 100-fold dilution having the most pronounced effect,increasing seedling rates by 50.6%-60.0%.Further analysis indicated that wood vinegar treatment enhanced seedling establishment by inducing a significant increase inα-amylase activity,leading to a 74.9%-213.6%increase in soluble sugar content in the sprouts during 2-8 d after flooding stress compared with the control.Additionally,the treatment increased superoxide dismutase and peroxidase activities in the sprouts,mitigating lipid peroxidation of the cell membranes,and notably lower water electrical conductivity was observed in wood vinegar-treated seeds compared with the control.In conclusion,soaking rice seeds in a 100-fold diluted wood vinegar solution improves rice seedling rates under flooding stress by mitigating oxidative damage and maintaining energy supply.This approach is valuable for developing cost-effective seed treatment technologies and offering novel strategies to improve seedling rates and uniformity of direct-seeded rice under flooding conditions.
文摘Satellite hydrology has reached a new era where a variety of earth observing systems,in conjunction with the development of data integrations,can provide a consistent monitoring of groundwater change,wetland dynamics,and drought evolution in regions where observations on the ground remain sparse or patchy.This synthesis review highlights the physical observables that are most useful to terrestrial hydrology:variable time-dependent gravity,passive and active microwave signals,optical reflectance,thermal infrared measurements,and altimetry,and this has been translated into hydrologic states and water fluxes:terrestrial water storage,ground water storage anomalies,inundation extent and hydroperiod,evapotranspiration,and multi-timescale drought indicators.We call attention to the role of satellite gravimetry in the transformation of basin-scale groundwater evaluation,synthetic aperture radar(SAR),and optical time series in transforming wetland science,however,to the characterization of hydroperiod and connectivity.In the case of drought,we recommend the use of both fast-responsive(soil moisture,evapotranspiration,thermal stress,and vegetation condition)in conjunction with slowly integrating storage anomalies to detect onset,intensification,and recovery,as well as rely on to diagnose the spread of deficits through the hydrologic system.In all these themes,we recognize the central action of enabling approaches that include multi-sensor fusion,data assimilation,and hybrid machine learning schemes in reducing ambiguity,scale gaps,and producing products of decision interest,and also highlighting ongoing issues in the quantification of uncertainty,consistency across long periods of time,and the separation of climate influence on human management of water.Research and operational priorities come as our final deduction to develop satellite hydrology to more trustworthy,explanation-seeking,and operationalizing monitoring designs of water security and ecosystem resilience.
基金supported by the National Natural Science Foundation of China(Grant Nos.32102311 and 32102338)the China Postdoctoral Science Foundation(Grant No.2021M690129).
文摘Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promise in augmenting cultivated apple resistance to abiotic stress.Although Alfin-like(ALs)proteins have demonstrated pivotal roles in dicotyledonous plants'response to abiotic stresses,knowledge about AL genes in apple rootstocks is limited,and their functions remain largely elusive.In this study,we identified and characterized 10 MpAL gene members in the apple rootstock genome,confirming their localization within the nucleus.Our investigation revealed the significant regulation of MpALs'expression under drought and abscisic acid(ABA)stresses in M.prunifolia.In this study,one of the members,MpAL1,was selected for further exploration in Arabidopsis and apple to explore its potential function in response to drought and ABA stresses.The results showed that overexpression-MpAL1 transgenic apple calli grew significantly better than WT and MpAL1-RNAi lines,which regulates the accumulation of H_(2)O_(2)and O_(2).-levels.Additionally,transgenic Arabidopsis plants overexpressing MpAL1 exhibited positively regulating antioxidant enzymes activities under stress treatments.Further study showed that silencing MpAL1 in apple plants showed obvious chlorosis in leaves,and accumulation of reactive oxygen species under drought stress.Moreover,our detailed analysis established that MpAL1 regulates several drought and ABA-responsive genes,exerting an influence on their expression in transgenic apple.Collectively,our findings identify MpAL1 as a positive regulator that increases drought stress in apple,shedding light on its potential significance in bolstering drought resistance in this fruit crop.
基金National Key Research and Development Program of China,No.2023YFC3006704National Natural Science Foundation of China,No.42171047CAS-CSIRO Partnership Joint Project of 2024,No.177GJHZ2023097MI。
文摘Accurate prediction of flood events is important for flood control and risk management.Machine learning techniques contributed greatly to advances in flood predictions,and existing studies mainly focused on predicting flood resource variables using single or hybrid machine learning techniques.However,class-based flood predictions have rarely been investigated,which can aid in quickly diagnosing comprehensive flood characteristics and proposing targeted management strategies.This study proposed a prediction approach of flood regime metrics and event classes coupling machine learning algorithms with clustering-deduced membership degrees.Five algorithms were adopted for this exploration.Results showed that the class membership degrees accurately determined event classes with class hit rates up to 100%,compared with the four classes clustered from nine regime metrics.The nonlinear algorithms(Multiple Linear Regression,Random Forest,and least squares-Support Vector Machine)outperformed the linear techniques(Multiple Linear Regression and Stepwise Regression)in predicting flood regime metrics.The proposed approach well predicted flood event classes with average class hit rates of 66.0%-85.4%and 47.2%-76.0%in calibration and validation periods,respectively,particularly for the slow and late flood events.The predictive capability of the proposed prediction approach for flood regime metrics and classes was considerably stronger than that of hydrological modeling approach.
