Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinit...Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.展开更多
Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to dr...Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.展开更多
Drought stress impairs crop growth and development.BEL1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regu...Drought stress impairs crop growth and development.BEL1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regulate plant response and defense to drought stress.Here we show that the BEL1-like transcription factor GhBLH5-A05 functions in cotton(Gossypium hirsutum)response and defense to drought stress.Expression of GhBLH5-A05 in cotton was induced by drought stress.Overexpression of GhBLH5-A05 in both Arabidopsis and cotton increased drought tolerance,whereas silencing GhBLH5-A05 in cotton resulted in elevated sensitivity to drought stress.GhBLH5-A05 binds to cis elements in the promoters of GhRD20-A09 and GhDREB2C-D05 to activate the expression of these genes.GhBLH5-A05 interacted with the KNOX transcription factor GhKNAT6-A03.Co-expression of GhBLH5-A05 and GhKNAT6-A03 increased the transcription of GhRD20-A09 and GhDREB2C-D05.We conclude that GhBLH5-A05 acts as a regulatory factor with GhKNAT6-A03 functioning in cotton response to drought stress by activating the expression of the drought-responsive genes GhRD20-A09 and GhDREB2C-D05.展开更多
Drought poses a significant challenge,restricting the productivity of medicinal and aromatic plants.The strain induced by drought can impede vital processes like respiration and photosynthesis,affecting various aspect...Drought poses a significant challenge,restricting the productivity of medicinal and aromatic plants.The strain induced by drought can impede vital processes like respiration and photosynthesis,affecting various aspects of plants’growth and metabolism.In response to this adversity,medicinal plants employ mechanisms such as morphological and structural adjustments,modulation of drought-resistant genes,and augmented synthesis of secondary metabolites and osmotic regulatory substances to alleviate the stress.Extreme water scarcity can lead to leaf wilting and may ultimately result in plant death.The cultivation and management of medicinal plants under stress conditions often differ from those of other crops.This is because the main goal with medicinal plants is not only to increase the yield of the above-ground parts but also to enhance the production of active ingredients such as essential oils.To elucidate these mechanisms of drought resistance in medicinal and aromatic plants,the current review provides a summary of recent literature encompassing studies on the morphology,physiology,and biochemistry of medicinal and aromatic plants under drought conditions.展开更多
Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and th...Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.展开更多
Persistent and severe drought induced by global climate change causes tree mortality mainly due to the hydraulic imbalance of conduit systems,but the magnitude of injury may be species dependent.A water-exclusion expe...Persistent and severe drought induced by global climate change causes tree mortality mainly due to the hydraulic imbalance of conduit systems,but the magnitude of injury may be species dependent.A water-exclusion experiment was carried out on seedlings of two tree species with distinct characteristics,i.e.,Fraxinus mandshurica and Larix gmelinii to examine hydraulic responses of leaf,stem,and root to drought stress.The two species displayed different hydraulic strategies and related traits in response to drought stress.L.gmelinii reduced its leaf hydraulic conductance by quick stomatal closure and a slow decline in leaf water potential,with a more isohydric stomatal regulation to maintain its water status.In contrast,F.mandshurica was more anisohydric with a negative stomatal safety margin,exhibiting strong resistance to embolism in stem and leafstem segmentation of hydraulic vulnerability to preserve the hydraulic integrity of stem.These differences in hydraulic behaviors and traits between the two species in response to drought stress provide a potential mechanism for their coexistence in temperate forests,including which in the forest modeling would improve our prediction of tree growth and distribution under future climate change.展开更多
Leaf rolling(LR)is one of the defensive mechanisms that plants have developed against adverse environmental conditions.LR is a typical drought response,promoting drought resistance in various gramineae species,includi...Leaf rolling(LR)is one of the defensive mechanisms that plants have developed against adverse environmental conditions.LR is a typical drought response,promoting drought resistance in various gramineae species,including wheat,maize,and rice.Rice cultivation faces the formidable challenge of water deprivation because of its high water requirements,which leads to drought-related symptoms in rice.LR is an important morphological characteristic that plays a key role in controlling water loss during water insufficiency,thereby regulating leaf area and stature,which are crucial agronomic traits determining yield criteria.Bulliform,sclerenchyma,mesophyll,and vascular bundles are the cells that engage in LR and commonly exhibit adaxial or abaxial types of rolling in rice.The specific genes linked to rolling,either adaxially or abaxially,are discussed here.In addition to the factors influencing LR,here is a short review of the morphological,physiological and molecular responses of this adaptation under drought stress.Moreover,this review highlights how LR combats the consequences of drought stress.The eco-physiological and molecular mechanisms underlying this morphological adaptation in rice should be further explored,as they might be useful in dealing with various degrees of drought tolerance.展开更多
N 6-methylated adenine(m6 A)is an emerging epigenetic marker in eukaryotic organisms that plays an important role in biological functions and in enriching genetic information.m6 A exerts these functions via the dynami...N 6-methylated adenine(m6 A)is an emerging epigenetic marker in eukaryotic organisms that plays an important role in biological functions and in enriching genetic information.m6 A exerts these functions via the dynamic interplay among m6 A writers,erasers,and readers.However,little is known about the underlying mechanisms of m6 A in plant growth and stress responses.Here,we identified 276 masked m6 A regulators from nine Rosaceae species(Pyrus bretschneideri,Pyrus betulifolia,Pyrus communis,Malus domestica,Fragaria vesca,Prunus avium,Prunus mume,Prunus persica,and Rubus occidentalis).We classified and named these genes in more detail based on phylogenetic and synteny analysis.The expansion of m6 A regulators in Maloideae was dated back to the recent whole-genome duplication(WGD)in Rosaceae.Based on the expression pattern analysis and gene structure analysis of m6 A regulators,m6 A was shown to be a significant factor in regulating plant development and resistance.In addition,PbrMTA1-silenced pear plants displayed significantly reduced drought tolerance and chlorophyll content,as well as increased electrolyte leakage and concentrations of malondialdehyde and H2 O2.展开更多
Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance i...Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance in transgenic apple(Malus×domestica)overexpressing MdFRK2,a key gene regulating fructose content and sugar metabolism.There is no obvious phenotypic difference between MdFRK2-overexpressing transgenic plants and WT plants under the well-watered condition.However,the transgenic plants and the grafted plants using MdFRK2-overexpressing rootstock exhibited improved tolerance to drought stress.Overexpression of MdFRK2 significantly promoted the growth of root system under drought stress.RNA sequencing showed that under drought stress,genes involved in sugar metabolism,transcription regulation,signal transduction or hormone metabolism were differentially expressed in MdFRK2 transgenic plants.Consistent with the gene expression profile,the activities of enzyme(SDH,FRK and NI)involved in sugar metabolism in the roots of MdFRK2 transgenic plants were significantly higher than those of untransformed control plants after drought stress.Under drought stress,overexpression of MdFRK2 promoted the accumulation of IAA,and decreased the contents of ABA and CK in apple root system.In conclusion,these results suggest that MdFRK2 can promote the growth of apple roots under drought stress by regulating sugar metabolism and accumulation,hormone metabolism and signal transduction,and then resist drought stress.展开更多
Drought is a severe environmental constraint,causing a significant reduction in crop productivity across the world.Salicylic acid(SA)is an important plant growth regulator that helps plants cope with the adverse effec...Drought is a severe environmental constraint,causing a significant reduction in crop productivity across the world.Salicylic acid(SA)is an important plant growth regulator that helps plants cope with the adverse effects induced by various abiotic stresses.The current study investigated the potential effects of SA on drought tolerance efficacy in two barley(Hordeum vulgare)genotypes,namely BARI barley 5 and BARI barley 7.Ten-day-old barley seedlings were exposed to drought stress by maintaining 7.5%soil moisture content in the absence or presence of 0.5,1.0 and 1.5 mM SA.Drought exposure led to severe damage to both genotypes,as indicated by phenotypic aberrations and reduction of dry biomass.On the other hand,the application of SA to drought-stressed plants protected both barley genotypes from the adverse effects of drought,which was reflected in the improvement of phenotypes and biomass production.SA supplementation improved relative water content and proline levels in drought-stressed barley genotypes,indicating the osmotic adjustment functions of SA under water-deficit conditions.Drought stress induced the accumulation of reactive oxygen species(ROS),such as hydrogen peroxide(H2O2)and superoxide(O_(2)•^(−)),and the lipid peroxidation product malondialdehyde(MDA)in the leaves of barley plants.Exogenous supply of SA reduced oxidative damage by restricting the accumulation of ROS through the stimulation of the activities of key antioxidant enzymes,including superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),ascorbate peroxidase(APX)and glutathione peroxidase(GPX).Among the three-applied concentrations of SA,0.5 mM SA exhibited better mitigating effects against drought stress considering the phenotypic performance and biochemical data.Furthermore,BARI barley 5 showed better performance under drought stress than BARI barley 7 in the presence of SA application.Collectively,our results suggest that SA played a crucial role in improving water status and antioxidant defense strategy to protect barley plants from the deleterious effects of water deficiency.展开更多
Small ubiquitin-like modifier(SUMO)E3 ligases that facilitate the conjugation of SUMO proteins to target substrates contain an SP-RING domain which is like the RING domain found in ubiquitin E3 ligases.In this study,w...Small ubiquitin-like modifier(SUMO)E3 ligases that facilitate the conjugation of SUMO proteins to target substrates contain an SP-RING domain which is like the RING domain found in ubiquitin E3 ligases.In this study,we isolated and characterized the Oryza sativa protein inhibitor of activated STAT like1(OsPIAL1)containing SP-RING domains,as the rice homolog of Arabidopsis PIALs.OsPIAL1 interacts with OsSUMO proteins but does not interact with rice SUMO-conjugating enzymes(OsSCEs).An analysis of transgenic rice plant shows that OsPIAL1 is involved in SUMO conjugation to SCEs but not in SUMO conjugation to substrates.In addition,this OsPIAL1 activity requires drought stress conditions.Expression profiles show that the OsPIAL1 gene is induced by only drought stress in the leaves,whereas it is repressed by ABA and abiotic stresses in the roots.Salt stress leads to the fastest decrease in OsPIAL1 transcripts in the roots.Furthermore,the stress experiments indicate that the transgenic rice plants overexpressing OsPIAL1 exhibit a drought stress-tolerant phenotype but a salt stress hypersensitive phenotype.Our results and those from Arabidopsis pial mutants suggest that PIALs act as a positive regulator in the drought stress response but as a negative regulator in the salt stress response.展开更多
Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse respon...Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse responses.However,the mechanism by which TCP transcription functions in drought resistance in Allium senescens is still not clear.Here,we obtained a total of 190,305 transcripts with 115,562 single gene clusters based on RNA-Seq sequencing of Allium senescens under drought stress.The total number of bases was 97,195,096 bp,and the average length was 841.06 bp.Furthermore,we found that there were eight genes of the TCP family that showed an upregulated expression trend under drought stress in Allium senescens.We carried out an investigation to determine the evolution and function of the AsTCP family and how they produce an effect in drought resistance.The 14 AsTCP genes were confirmed and divided into class I and class II containing CIN and CYC/TBI subfamilies,respectively.We also found that the expression of AsTCP17 was remarkably upregulated with drought treatment.Besides,the transformation of AsTCP17 in Arabidopsis revealed that the protective enzymes,namely polyphenol oxidase(POD)and superoxide dismutase(SOD),were increased by 0.4 and 0.8 times,respectively.Chlorophyll content was also increased,while the H2O2 and malondialdehyde(MDA)contents were decreased.Staining assays with 3,3′-diaminobenzidine(DAB)also suggested that the AsTCP17 downregulates reactive oxygen species(ROS)accumulation.In addition,overexpression of the AsTCP17 affected the accumulation of drought-related hormones in plants,and the synthesis of ABA.The expression of AtSVP and AtNCED3,related ABA synthesis pathway genes,indicated that the level of expression of AtSVP and AtNCED3 was obviously enhanced,with the overexpression of line 6 showing a 20.6-fold and 7.0-fold increase,respectively.Taken together,our findings systematically analyze the AsTCPs family at the transcriptome expression level in Allium senescens,and we also demonstrated that AsTCP17 protein,as a positive regulator,was involved in drought resistance of Allium senescens.In addition,our research contributes to the comprehensive understanding of the drought stress defense mechanism in herbaceous plants.展开更多
Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination u...Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination under drought conditions is still poorly understood.Therefore,we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress.Rice seeds were treated with different concentrations of melatonin(i.e.,0,20,100,and 500μM)and drought stress was simulated with 5%polyethylene glycol 6000(PEG6000).The results showed that 100μM melatonin can effectively improve the germination potential,rate and index;the vigor index of rice seeds;and the length of the shoot and root.In addition,that treatment also increased the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and reduced the content of malondialdehyde(MDA).The grey relational grade between the shoot MDA content and the melatonin seed-soaking treatment was the highest,which could be useful for evaluating the effect of melatonin on drought tolerance.Two-way analysis of variance showed that the effect of single melatonin treatment on rice seeds was more significant than that of single drought stress and interaction treatment of drought and melatonin(p<0.05).The subordinate function results showed that 100μM melatonin significantly improved the germination and physiological indexes of rice seeds and effectively alleviated the adverse effects of drought stress on rice seedlings.The results helped to improve the understanding of the morphological and physiological involvement of melatonin in promoting seed germination and seedling development under drought stress.展开更多
Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arab...Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arabidopsis thaliana.In this study,NtBRL3 was constructed as a vector and genetically transformed to obtain‘N.Tobacco K326’overexpression of NtBRL3.The enzyme activities of transgenic tobacco and wild-type tobacco were measured and transcriptome and metabolome analyses were performed.The results showed that the antioxidant enzymes of transgenic tobacco were more active under drought conditions,and 85 significantly differentially metabolites and 106 significantly differentially expressed genes were identified in the metabolome and transcriptome analyses,respectively.Transgenic tobacco NtBRL3ox demonstrated an excessive accumulation of droughtrelated metabolites,sugars such as sucrose and maltotetraose,and amino acids such as proline,compared with WT.We discovered drought-related differential genes in the root transcriptome,among which LOX6,RD22,WSD1,CCD8,and UGT were key genes which play an important role in plant response to drought stress.Our results demonstrate that NtBRL3 overexpression in K326 enhances drought resistance in transgenic tobacco.展开更多
Herbaceous peony(Paeonia lactiflora Pall.),as a high-end cut flower in the international market,has high ornamental and medicinal values.But in Northern China,drought is a major environmental factor influencing the gr...Herbaceous peony(Paeonia lactiflora Pall.),as a high-end cut flower in the international market,has high ornamental and medicinal values.But in Northern China,drought is a major environmental factor influencing the growth and development of P.lactiflora.Quantitative real-time polymerase chain reaction(qRT-PCR)can evaluate gene expression levels under different stress conditions,and stable internal reference is the key for qRT-PCR.At present,there is no systematic screening of internal reference for correcting gene expressions of P.lactiflora in response to drought stress.In this study,10 candidate genes[ubiquitin(UBQ2),UBQ1,elongation factor 1-α(EF-1α),Histidine(His),eukaryotic initiation factor(eIF),tubulin(TUB),actin(ACT),UBQ3,ACT2,RNA polymerase II(RNA Pol II)]were chosen,and 4 analysis methods were used to compare the stabilities for these 10 genes coping with drought stress.Due to the difference of operation methods,the results of different analysis were distinct,and the final comprehensive analysis indicated that EF-1αwas a relatively stable internal reference gene for P.lactiflora under drought stress.Also,UBQ1 and UBQ2 were the best reference gene combination according to GeNorm analysis.This study will lay a foundation for screening the key genes of P.lactiflora in response to drought stress.展开更多
Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studyin...Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studying the regulation mechanism of osmotic adjustment and water transportation under drought stress,and understanding the physiological and biochemical characteristics and stress resistance mechanism.展开更多
Different genotypes of Bambara groundnut (Vigna subterranea L. Verdc) grow well under conducive environmental conditions, provided that adequate soil moisture is available during vegetative and reproductive phases. Ho...Different genotypes of Bambara groundnut (Vigna subterranea L. Verdc) grow well under conducive environmental conditions, provided that adequate soil moisture is available during vegetative and reproductive phases. However, drought stress is the major limiting factor to bambara production, which accounts for up to 40% of yield losses. This situation could worsen due to drastic and rapid changes in the global climate. Landraces grown by farmers are low-yielding. Understanding the physiological response of different genotypes to drought stress is key to achieving food security through crop improvement and diversification. This study focused on variations in the response of Bambara groundnut genotypes to intermittent drought stress during the crop’s critical growth (vegetative and reproductive) stages. The experiment was undertaken at CSIR-Crops Research Institute Screen-house. The treatments were used in a factorial experiment with three replications in a randomized complete block design. The Bambara genotypes showed considerable variability in tolerance to drought stress. Drought stress during vegetative and reproductive stages significantly reduced crop growth indices, the leaf relative water content, chlorophyll content and leaf area. Drought stress during vegetative and reproductive stages had a more severe impact on the seed yield of genotype Nav Red, reducing it by 69% and 13%, respectively. Farmers should pay more attention to adopting drought-tolerant and high-yielding varieties for improved Bambara groundnut productivity and livelihoods.展开更多
Drought impacts in arid desert ecosystems can result in decreased ecosystem productivity and biodiversity.Implementation of restoration projects in arid desert environments is largely dependent on water availabi...Drought impacts in arid desert ecosystems can result in decreased ecosystem productivity and biodiversity.Implementation of restoration projects in arid desert environments is largely dependent on water availability and soil moisture condition.This study investigated the influence of induced drought stress by using polyethylene glycol(PEG-6000)solution on germination viz.Cenchrus ciliaris and Cenchrus setigerus as the important rangeland species.The water stress potential treatments were 0(control),-0.5 MPa,-1.0 MPa,-1.5 MPa,and-2.0 MPa.The extent of seed germination was severely affected by decreased water stress potential.As drought increased,the percentage of germination decreased in both Cenchrus’species.The water deficit at-0.5 MPa showed a significant(P<0.001)reduction in the final germination percentage in the case of C.setigerus and C.ciliaris by 65%and 42.5%,respectively.At-1.0 MPa to-1.5 MPa,changes in intermediate germination were observed in C.ciliaris(from 35%to 17.5%,respectively)and C.setigerus(from 22.5%to 11.25%respectively).Higher levels of water stress(-2.0 MPa)prevented the survival of both species.Understanding the germination strategies of native desert plant species associated with drought stress and identifying favorable conditions during the germination process can be useful for restoration practices and rangeland management actions to improve desert ecosystems and maintain biodiversity.展开更多
Drought and salt stresses,the major environmental abiotic stresses in agriculture worldwide,affect plant growth,crop productivity,and quality.Therefore,developing crops with higher drought and salt tolerance is highly...Drought and salt stresses,the major environmental abiotic stresses in agriculture worldwide,affect plant growth,crop productivity,and quality.Therefore,developing crops with higher drought and salt tolerance is highly desirable.This study reported the isolation,biological function,and molecular characterization of a novel maspardin gene,OsMas1,from rice.The OsMas1 protein was localized to the cytoplasm.The expression levels of OsMas1 were up-regulated under mannitol,PEG6000,NaCl,and abscisic acid(ABA) treatments in rice.The OsMas1 gene was introduced into the rice cultivar Zhonghua 11(wild type,WT).OsMas1-overexpression(OsMas1-OE) plants exhibited significantly enhanced salt and drought tolerance;in contrast,OsMas1-interference(OsMas1-RNAi) plants exhibited decreased tolerance to salt and drought stresses,compared with WT.OsMas1-OE plants exhibited enhanced hypersensitivity,while OsMas1-RNAi plants showed less sensitivity to exogenous ABA treatment at both germination and post-germination stages.ABA,proline and K+ contents and superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),and photosynthesis activities were significantly increased.In contrast,malonaldehyde(MDA),hydrogen peroxide(H2O2),superoxide anion radical(O2-··),and Na+ contents were significantly decreased in OsMas1-OE plants compared with OsMas1-RNAi and WT plants.Overexpression of OsMas1 up-regulated the genes involved in ABA signaling,proline biosynthesis,reactive oxygen species(ROS)-scavenging system,photosynthesis,and ion transport under salt and drought stresses.Our results indicate that the OsMas1 gene improves salt and drought tolerance in rice,which may serve as a candidate gene for enhancing crop resistance to abiotic stresses.展开更多
Increased evidence has shown that hydrogen sulfide(H_(2)S),a novel gasotransmitter,could enhance drought resistance in plants by inducing stomatal closure,with concurrent enhancement of photosynthetic efficiency,but l...Increased evidence has shown that hydrogen sulfide(H_(2)S),a novel gasotransmitter,could enhance drought resistance in plants by inducing stomatal closure,with concurrent enhancement of photosynthetic efficiency,but little is known about the mechanism behind this contradictory phenomenon.This study examined the regulating mechanism of H_(2)S in response to drought stress fromstomatal and non-stomatal factors in Chinese cabbage.The results showed that exogenous H_(2)S could increase the accumulation of photosynthetic pigments and alleviate the damage caused by drought stress.It also regulated the expression in transcriptional level and the activity of ribulose 1,5-bisphosphate carboxylase/oxygenase(BrRuBisCO)under drought stress.The large subunit of BrRuBisCO was found to be modified by S-sulfhydration,which might be the reason for its increased enzyme activity.The fluxes of Cl^(−),K^(+),and H^(+)in the guard cells were detected by non-invasive micro-test techniques while under drought stress.The results indicated that H_(2)S signaling induced a transmembrane Cl^(−)and H^(+)efflux and inhibited K^(+)influx,and the Cl^(−)channel was the main responders for H_(2)S-regulated stomatal movement.In conclusion,H_(2)S signal not only activated the ion channel proteins located in the guard cell membrane to induce stomatal closure,but also regulated the transcriptional expression and the activity of RuBisCO,a non-stomatal factor to enhance the photosynthetic efficiency of leaves.There is therefore a beneficial balance between the regulation of H_(2)S signaling on stomatal factors and non-stomatal factors due to drought stress,which needs to be better understood to apply it practically to increase crop yields.展开更多
基金financed by the National Key Research and Development Program,China(Grant Nos.2022YFE0113400 and 2022YFD1500402)National Natural Science Foundation of China(Grant No.32001466)+3 种基金Scientific and Technological Innovation Fund of Carbon Emissions Peak and Neutrality of Jiangsu Provincial Department of Science and Technology,China(Grant Nos.BE2022304 and BE2022305)Joints Funds of the National Natural Science Foundation of China(Grant No.U20A2022)Postdoctoral Research Foundation of China(Grant No.2020M671628)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.
基金supported by grants from the Natural Science Foundation of China (Grant No.42077040)the open competition program of top ten critical priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province (Grant Nos.2022SDZG09,2023SDZG09)+1 种基金the Natural Science Foundation of Guangdong (Grant No.2021B1515010868)the GDAS Project of Science and Technology Development(2021GDASYL-20210103023)。
文摘Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.
基金supported by the Project from the Ministry of Agriculture of China for Transgenic Research(2014ZX0800927B)the National Natural Science Foundation of China(31871667).
文摘Drought stress impairs crop growth and development.BEL1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regulate plant response and defense to drought stress.Here we show that the BEL1-like transcription factor GhBLH5-A05 functions in cotton(Gossypium hirsutum)response and defense to drought stress.Expression of GhBLH5-A05 in cotton was induced by drought stress.Overexpression of GhBLH5-A05 in both Arabidopsis and cotton increased drought tolerance,whereas silencing GhBLH5-A05 in cotton resulted in elevated sensitivity to drought stress.GhBLH5-A05 binds to cis elements in the promoters of GhRD20-A09 and GhDREB2C-D05 to activate the expression of these genes.GhBLH5-A05 interacted with the KNOX transcription factor GhKNAT6-A03.Co-expression of GhBLH5-A05 and GhKNAT6-A03 increased the transcription of GhRD20-A09 and GhDREB2C-D05.We conclude that GhBLH5-A05 acts as a regulatory factor with GhKNAT6-A03 functioning in cotton response to drought stress by activating the expression of the drought-responsive genes GhRD20-A09 and GhDREB2C-D05.
文摘Drought poses a significant challenge,restricting the productivity of medicinal and aromatic plants.The strain induced by drought can impede vital processes like respiration and photosynthesis,affecting various aspects of plants’growth and metabolism.In response to this adversity,medicinal plants employ mechanisms such as morphological and structural adjustments,modulation of drought-resistant genes,and augmented synthesis of secondary metabolites and osmotic regulatory substances to alleviate the stress.Extreme water scarcity can lead to leaf wilting and may ultimately result in plant death.The cultivation and management of medicinal plants under stress conditions often differ from those of other crops.This is because the main goal with medicinal plants is not only to increase the yield of the above-ground parts but also to enhance the production of active ingredients such as essential oils.To elucidate these mechanisms of drought resistance in medicinal and aromatic plants,the current review provides a summary of recent literature encompassing studies on the morphology,physiology,and biochemistry of medicinal and aromatic plants under drought conditions.
基金This research was funded by the National Key Research and Development Program of China(2023YFD2301505).
文摘Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.
基金the National Science and Technology Support Program of China(2011BAD37B01)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R09)+1 种基金the National Key Research and Development Program of China(2016YFD0600201)the Fundamental Research Funds for the Central Universities(2572018AA07)。
文摘Persistent and severe drought induced by global climate change causes tree mortality mainly due to the hydraulic imbalance of conduit systems,but the magnitude of injury may be species dependent.A water-exclusion experiment was carried out on seedlings of two tree species with distinct characteristics,i.e.,Fraxinus mandshurica and Larix gmelinii to examine hydraulic responses of leaf,stem,and root to drought stress.The two species displayed different hydraulic strategies and related traits in response to drought stress.L.gmelinii reduced its leaf hydraulic conductance by quick stomatal closure and a slow decline in leaf water potential,with a more isohydric stomatal regulation to maintain its water status.In contrast,F.mandshurica was more anisohydric with a negative stomatal safety margin,exhibiting strong resistance to embolism in stem and leafstem segmentation of hydraulic vulnerability to preserve the hydraulic integrity of stem.These differences in hydraulic behaviors and traits between the two species in response to drought stress provide a potential mechanism for their coexistence in temperate forests,including which in the forest modeling would improve our prediction of tree growth and distribution under future climate change.
文摘Leaf rolling(LR)is one of the defensive mechanisms that plants have developed against adverse environmental conditions.LR is a typical drought response,promoting drought resistance in various gramineae species,including wheat,maize,and rice.Rice cultivation faces the formidable challenge of water deprivation because of its high water requirements,which leads to drought-related symptoms in rice.LR is an important morphological characteristic that plays a key role in controlling water loss during water insufficiency,thereby regulating leaf area and stature,which are crucial agronomic traits determining yield criteria.Bulliform,sclerenchyma,mesophyll,and vascular bundles are the cells that engage in LR and commonly exhibit adaxial or abaxial types of rolling in rice.The specific genes linked to rolling,either adaxially or abaxially,are discussed here.In addition to the factors influencing LR,here is a short review of the morphological,physiological and molecular responses of this adaptation under drought stress.Moreover,this review highlights how LR combats the consequences of drought stress.The eco-physiological and molecular mechanisms underlying this morphological adaptation in rice should be further explored,as they might be useful in dealing with various degrees of drought tolerance.
基金supported by the National Key Research and Development Program of China (Grant No. 2019YFD1000102)the National Science Foundation of China (Grant Nos. 31872070, 32072538)+4 种基金the Jiangsu Agriculture Science and Technology Innovation Fund (CX Grant No. 183065)the Fundamental Research Funds for the Central Universities of Nanjing Agricultural University (Grant No. KYZ201607)the College of Horticulture SRT project of the Nanjing Agriculture University (Grant No. 202011YX05)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Undergraduate Training Program for Innovation and Entrepreneurship (Grant No. S20190040)
文摘N 6-methylated adenine(m6 A)is an emerging epigenetic marker in eukaryotic organisms that plays an important role in biological functions and in enriching genetic information.m6 A exerts these functions via the dynamic interplay among m6 A writers,erasers,and readers.However,little is known about the underlying mechanisms of m6 A in plant growth and stress responses.Here,we identified 276 masked m6 A regulators from nine Rosaceae species(Pyrus bretschneideri,Pyrus betulifolia,Pyrus communis,Malus domestica,Fragaria vesca,Prunus avium,Prunus mume,Prunus persica,and Rubus occidentalis).We classified and named these genes in more detail based on phylogenetic and synteny analysis.The expansion of m6 A regulators in Maloideae was dated back to the recent whole-genome duplication(WGD)in Rosaceae.Based on the expression pattern analysis and gene structure analysis of m6 A regulators,m6 A was shown to be a significant factor in regulating plant development and resistance.In addition,PbrMTA1-silenced pear plants displayed significantly reduced drought tolerance and chlorophyll content,as well as increased electrolyte leakage and concentrations of malondialdehyde and H2 O2.
基金supported by the National Natural Science Foundation of China(Grant No.32001988)the National Natural Science Foundation of Shaanxi Province(Grant No.2020JC-21)+1 种基金the Open Project Program of State Key Laboratory of Crop Stress Biology for Arid Areas(Grant No.CSBAA2020002)the earmarked fund for the China Agriculture Research System(Grant No.CARS-27)。
文摘Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance in transgenic apple(Malus×domestica)overexpressing MdFRK2,a key gene regulating fructose content and sugar metabolism.There is no obvious phenotypic difference between MdFRK2-overexpressing transgenic plants and WT plants under the well-watered condition.However,the transgenic plants and the grafted plants using MdFRK2-overexpressing rootstock exhibited improved tolerance to drought stress.Overexpression of MdFRK2 significantly promoted the growth of root system under drought stress.RNA sequencing showed that under drought stress,genes involved in sugar metabolism,transcription regulation,signal transduction or hormone metabolism were differentially expressed in MdFRK2 transgenic plants.Consistent with the gene expression profile,the activities of enzyme(SDH,FRK and NI)involved in sugar metabolism in the roots of MdFRK2 transgenic plants were significantly higher than those of untransformed control plants after drought stress.Under drought stress,overexpression of MdFRK2 promoted the accumulation of IAA,and decreased the contents of ABA and CK in apple root system.In conclusion,these results suggest that MdFRK2 can promote the growth of apple roots under drought stress by regulating sugar metabolism and accumulation,hormone metabolism and signal transduction,and then resist drought stress.
文摘Drought is a severe environmental constraint,causing a significant reduction in crop productivity across the world.Salicylic acid(SA)is an important plant growth regulator that helps plants cope with the adverse effects induced by various abiotic stresses.The current study investigated the potential effects of SA on drought tolerance efficacy in two barley(Hordeum vulgare)genotypes,namely BARI barley 5 and BARI barley 7.Ten-day-old barley seedlings were exposed to drought stress by maintaining 7.5%soil moisture content in the absence or presence of 0.5,1.0 and 1.5 mM SA.Drought exposure led to severe damage to both genotypes,as indicated by phenotypic aberrations and reduction of dry biomass.On the other hand,the application of SA to drought-stressed plants protected both barley genotypes from the adverse effects of drought,which was reflected in the improvement of phenotypes and biomass production.SA supplementation improved relative water content and proline levels in drought-stressed barley genotypes,indicating the osmotic adjustment functions of SA under water-deficit conditions.Drought stress induced the accumulation of reactive oxygen species(ROS),such as hydrogen peroxide(H2O2)and superoxide(O_(2)•^(−)),and the lipid peroxidation product malondialdehyde(MDA)in the leaves of barley plants.Exogenous supply of SA reduced oxidative damage by restricting the accumulation of ROS through the stimulation of the activities of key antioxidant enzymes,including superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),ascorbate peroxidase(APX)and glutathione peroxidase(GPX).Among the three-applied concentrations of SA,0.5 mM SA exhibited better mitigating effects against drought stress considering the phenotypic performance and biochemical data.Furthermore,BARI barley 5 showed better performance under drought stress than BARI barley 7 in the presence of SA application.Collectively,our results suggest that SA played a crucial role in improving water status and antioxidant defense strategy to protect barley plants from the deleterious effects of water deficiency.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(Grant No.2017R1D1A1B03030725).
文摘Small ubiquitin-like modifier(SUMO)E3 ligases that facilitate the conjugation of SUMO proteins to target substrates contain an SP-RING domain which is like the RING domain found in ubiquitin E3 ligases.In this study,we isolated and characterized the Oryza sativa protein inhibitor of activated STAT like1(OsPIAL1)containing SP-RING domains,as the rice homolog of Arabidopsis PIALs.OsPIAL1 interacts with OsSUMO proteins but does not interact with rice SUMO-conjugating enzymes(OsSCEs).An analysis of transgenic rice plant shows that OsPIAL1 is involved in SUMO conjugation to SCEs but not in SUMO conjugation to substrates.In addition,this OsPIAL1 activity requires drought stress conditions.Expression profiles show that the OsPIAL1 gene is induced by only drought stress in the leaves,whereas it is repressed by ABA and abiotic stresses in the roots.Salt stress leads to the fastest decrease in OsPIAL1 transcripts in the roots.Furthermore,the stress experiments indicate that the transgenic rice plants overexpressing OsPIAL1 exhibit a drought stress-tolerant phenotype but a salt stress hypersensitive phenotype.Our results and those from Arabidopsis pial mutants suggest that PIALs act as a positive regulator in the drought stress response but as a negative regulator in the salt stress response.
基金supported by the Hebei Grass Industry Innovation Team of the Modern Agricultural Industry Technology System(HBCT2018050204).
文摘Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse responses.However,the mechanism by which TCP transcription functions in drought resistance in Allium senescens is still not clear.Here,we obtained a total of 190,305 transcripts with 115,562 single gene clusters based on RNA-Seq sequencing of Allium senescens under drought stress.The total number of bases was 97,195,096 bp,and the average length was 841.06 bp.Furthermore,we found that there were eight genes of the TCP family that showed an upregulated expression trend under drought stress in Allium senescens.We carried out an investigation to determine the evolution and function of the AsTCP family and how they produce an effect in drought resistance.The 14 AsTCP genes were confirmed and divided into class I and class II containing CIN and CYC/TBI subfamilies,respectively.We also found that the expression of AsTCP17 was remarkably upregulated with drought treatment.Besides,the transformation of AsTCP17 in Arabidopsis revealed that the protective enzymes,namely polyphenol oxidase(POD)and superoxide dismutase(SOD),were increased by 0.4 and 0.8 times,respectively.Chlorophyll content was also increased,while the H2O2 and malondialdehyde(MDA)contents were decreased.Staining assays with 3,3′-diaminobenzidine(DAB)also suggested that the AsTCP17 downregulates reactive oxygen species(ROS)accumulation.In addition,overexpression of the AsTCP17 affected the accumulation of drought-related hormones in plants,and the synthesis of ABA.The expression of AtSVP and AtNCED3,related ABA synthesis pathway genes,indicated that the level of expression of AtSVP and AtNCED3 was obviously enhanced,with the overexpression of line 6 showing a 20.6-fold and 7.0-fold increase,respectively.Taken together,our findings systematically analyze the AsTCPs family at the transcriptome expression level in Allium senescens,and we also demonstrated that AsTCP17 protein,as a positive regulator,was involved in drought resistance of Allium senescens.In addition,our research contributes to the comprehensive understanding of the drought stress defense mechanism in herbaceous plants.
基金This work was funded by the National Natural Science Foundation of China(31971923,31301650)the National Key R&D Program of China(2017YFD0301501)+2 种基金the Hunan Provincial Natural Science Foundation of China(2020JJ4360)the Key Scientific Research Project of Hunan Provincial Education Department of China(19A220)Innovation and Entrepreneurship Training Program for College Students of Hunan Agricultural University(XCX2021038).
文摘Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination under drought conditions is still poorly understood.Therefore,we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress.Rice seeds were treated with different concentrations of melatonin(i.e.,0,20,100,and 500μM)and drought stress was simulated with 5%polyethylene glycol 6000(PEG6000).The results showed that 100μM melatonin can effectively improve the germination potential,rate and index;the vigor index of rice seeds;and the length of the shoot and root.In addition,that treatment also increased the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and reduced the content of malondialdehyde(MDA).The grey relational grade between the shoot MDA content and the melatonin seed-soaking treatment was the highest,which could be useful for evaluating the effect of melatonin on drought tolerance.Two-way analysis of variance showed that the effect of single melatonin treatment on rice seeds was more significant than that of single drought stress and interaction treatment of drought and melatonin(p<0.05).The subordinate function results showed that 100μM melatonin significantly improved the germination and physiological indexes of rice seeds and effectively alleviated the adverse effects of drought stress on rice seedlings.The results helped to improve the understanding of the morphological and physiological involvement of melatonin in promoting seed germination and seedling development under drought stress.
基金supported by the Science and Technology Project of Guizhou Tobacco Company(2021XM04)the Creation of“Tobacco T-DNA Activation Insertion Mutant Library and Screening of Important Trait Mutants”Project of Guizhou University Talent Introduction(Guizhou University Hezi[2013]50).
文摘Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arabidopsis thaliana.In this study,NtBRL3 was constructed as a vector and genetically transformed to obtain‘N.Tobacco K326’overexpression of NtBRL3.The enzyme activities of transgenic tobacco and wild-type tobacco were measured and transcriptome and metabolome analyses were performed.The results showed that the antioxidant enzymes of transgenic tobacco were more active under drought conditions,and 85 significantly differentially metabolites and 106 significantly differentially expressed genes were identified in the metabolome and transcriptome analyses,respectively.Transgenic tobacco NtBRL3ox demonstrated an excessive accumulation of droughtrelated metabolites,sugars such as sucrose and maltotetraose,and amino acids such as proline,compared with WT.We discovered drought-related differential genes in the root transcriptome,among which LOX6,RD22,WSD1,CCD8,and UGT were key genes which play an important role in plant response to drought stress.Our results demonstrate that NtBRL3 overexpression in K326 enhances drought resistance in transgenic tobacco.
基金funded by Jiangsu Agricultural Science and Technology Innovation Fund[CX(20)2030 to J.T.]Qing Lan Project of Jiangsu Province and High-Level Talent Support Program of Yangzhou University.The Key Disciplines of Jiangsu Province.
文摘Herbaceous peony(Paeonia lactiflora Pall.),as a high-end cut flower in the international market,has high ornamental and medicinal values.But in Northern China,drought is a major environmental factor influencing the growth and development of P.lactiflora.Quantitative real-time polymerase chain reaction(qRT-PCR)can evaluate gene expression levels under different stress conditions,and stable internal reference is the key for qRT-PCR.At present,there is no systematic screening of internal reference for correcting gene expressions of P.lactiflora in response to drought stress.In this study,10 candidate genes[ubiquitin(UBQ2),UBQ1,elongation factor 1-α(EF-1α),Histidine(His),eukaryotic initiation factor(eIF),tubulin(TUB),actin(ACT),UBQ3,ACT2,RNA polymerase II(RNA Pol II)]were chosen,and 4 analysis methods were used to compare the stabilities for these 10 genes coping with drought stress.Due to the difference of operation methods,the results of different analysis were distinct,and the final comprehensive analysis indicated that EF-1αwas a relatively stable internal reference gene for P.lactiflora under drought stress.Also,UBQ1 and UBQ2 were the best reference gene combination according to GeNorm analysis.This study will lay a foundation for screening the key genes of P.lactiflora in response to drought stress.
基金Supported by Thousand Talents Program for High-end Innovative Talents of Qinghai Province(2020,2022).
文摘Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studying the regulation mechanism of osmotic adjustment and water transportation under drought stress,and understanding the physiological and biochemical characteristics and stress resistance mechanism.
文摘Different genotypes of Bambara groundnut (Vigna subterranea L. Verdc) grow well under conducive environmental conditions, provided that adequate soil moisture is available during vegetative and reproductive phases. However, drought stress is the major limiting factor to bambara production, which accounts for up to 40% of yield losses. This situation could worsen due to drastic and rapid changes in the global climate. Landraces grown by farmers are low-yielding. Understanding the physiological response of different genotypes to drought stress is key to achieving food security through crop improvement and diversification. This study focused on variations in the response of Bambara groundnut genotypes to intermittent drought stress during the crop’s critical growth (vegetative and reproductive) stages. The experiment was undertaken at CSIR-Crops Research Institute Screen-house. The treatments were used in a factorial experiment with three replications in a randomized complete block design. The Bambara genotypes showed considerable variability in tolerance to drought stress. Drought stress during vegetative and reproductive stages significantly reduced crop growth indices, the leaf relative water content, chlorophyll content and leaf area. Drought stress during vegetative and reproductive stages had a more severe impact on the seed yield of genotype Nav Red, reducing it by 69% and 13%, respectively. Farmers should pay more attention to adopting drought-tolerant and high-yielding varieties for improved Bambara groundnut productivity and livelihoods.
基金This study was made possible by generous support of the Kuwait Institute for Scientific Research(KISR).
文摘Drought impacts in arid desert ecosystems can result in decreased ecosystem productivity and biodiversity.Implementation of restoration projects in arid desert environments is largely dependent on water availability and soil moisture condition.This study investigated the influence of induced drought stress by using polyethylene glycol(PEG-6000)solution on germination viz.Cenchrus ciliaris and Cenchrus setigerus as the important rangeland species.The water stress potential treatments were 0(control),-0.5 MPa,-1.0 MPa,-1.5 MPa,and-2.0 MPa.The extent of seed germination was severely affected by decreased water stress potential.As drought increased,the percentage of germination decreased in both Cenchrus’species.The water deficit at-0.5 MPa showed a significant(P<0.001)reduction in the final germination percentage in the case of C.setigerus and C.ciliaris by 65%and 42.5%,respectively.At-1.0 MPa to-1.5 MPa,changes in intermediate germination were observed in C.ciliaris(from 35%to 17.5%,respectively)and C.setigerus(from 22.5%to 11.25%respectively).Higher levels of water stress(-2.0 MPa)prevented the survival of both species.Understanding the germination strategies of native desert plant species associated with drought stress and identifying favorable conditions during the germination process can be useful for restoration practices and rangeland management actions to improve desert ecosystems and maintain biodiversity.
基金supported by the Natural Science Foundation of Jiangsu Province, China (BK20191483)the Natural Science Fund for Colleges and Universities in Jiangsu Province, China (20KJA180004)+2 种基金the Postgraduate Practice Innovation Program of Jiangsu Province, China (SJCX20_1339)the College Student Practice Innovation Program of Jiangsu Province, China (202111049104H, 202211049133H and 202211049138H)the Talent Introduction Research Project of Huaiyin Institute of Technology, China (Z301B16534)。
文摘Drought and salt stresses,the major environmental abiotic stresses in agriculture worldwide,affect plant growth,crop productivity,and quality.Therefore,developing crops with higher drought and salt tolerance is highly desirable.This study reported the isolation,biological function,and molecular characterization of a novel maspardin gene,OsMas1,from rice.The OsMas1 protein was localized to the cytoplasm.The expression levels of OsMas1 were up-regulated under mannitol,PEG6000,NaCl,and abscisic acid(ABA) treatments in rice.The OsMas1 gene was introduced into the rice cultivar Zhonghua 11(wild type,WT).OsMas1-overexpression(OsMas1-OE) plants exhibited significantly enhanced salt and drought tolerance;in contrast,OsMas1-interference(OsMas1-RNAi) plants exhibited decreased tolerance to salt and drought stresses,compared with WT.OsMas1-OE plants exhibited enhanced hypersensitivity,while OsMas1-RNAi plants showed less sensitivity to exogenous ABA treatment at both germination and post-germination stages.ABA,proline and K+ contents and superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),and photosynthesis activities were significantly increased.In contrast,malonaldehyde(MDA),hydrogen peroxide(H2O2),superoxide anion radical(O2-··),and Na+ contents were significantly decreased in OsMas1-OE plants compared with OsMas1-RNAi and WT plants.Overexpression of OsMas1 up-regulated the genes involved in ABA signaling,proline biosynthesis,reactive oxygen species(ROS)-scavenging system,photosynthesis,and ion transport under salt and drought stresses.Our results indicate that the OsMas1 gene improves salt and drought tolerance in rice,which may serve as a candidate gene for enhancing crop resistance to abiotic stresses.
基金funded by the National Natural Science Foundation of China(32172550 and 31972428)Shanxi Province Natural Science Foundation(20210302123431)Research Project Supported by Shanxi Scholarship Council of China(2020-014).
文摘Increased evidence has shown that hydrogen sulfide(H_(2)S),a novel gasotransmitter,could enhance drought resistance in plants by inducing stomatal closure,with concurrent enhancement of photosynthetic efficiency,but little is known about the mechanism behind this contradictory phenomenon.This study examined the regulating mechanism of H_(2)S in response to drought stress fromstomatal and non-stomatal factors in Chinese cabbage.The results showed that exogenous H_(2)S could increase the accumulation of photosynthetic pigments and alleviate the damage caused by drought stress.It also regulated the expression in transcriptional level and the activity of ribulose 1,5-bisphosphate carboxylase/oxygenase(BrRuBisCO)under drought stress.The large subunit of BrRuBisCO was found to be modified by S-sulfhydration,which might be the reason for its increased enzyme activity.The fluxes of Cl^(−),K^(+),and H^(+)in the guard cells were detected by non-invasive micro-test techniques while under drought stress.The results indicated that H_(2)S signaling induced a transmembrane Cl^(−)and H^(+)efflux and inhibited K^(+)influx,and the Cl^(−)channel was the main responders for H_(2)S-regulated stomatal movement.In conclusion,H_(2)S signal not only activated the ion channel proteins located in the guard cell membrane to induce stomatal closure,but also regulated the transcriptional expression and the activity of RuBisCO,a non-stomatal factor to enhance the photosynthetic efficiency of leaves.There is therefore a beneficial balance between the regulation of H_(2)S signaling on stomatal factors and non-stomatal factors due to drought stress,which needs to be better understood to apply it practically to increase crop yields.
