OFP is a class of plant-specific transcription factors that play important roles in the regulation of plant organ morphogenesis and response to abiotic stresses.In order to study the characterization of soybean OFP transcription factor family members and their roles in drought stress and salt stress,bioinformatics methods were applied to identify and analyze soybean OFP family members.The results showed that:a total of 41 GmOFPs,named GmOFP-1—GmOFP-41,were identified in soybean;these genes were unevenly distributed on 19 chromosomes of soybean,encoding 152—414 amino acids;subcellular localization predicted that soybean OFP proteins were mainly localized in nucleus,chloroplasts,and mitochondria;a total of 10 conserved motifs were identified in soybean OFP proteins,conservative Motifs 1 and 2 were present in all OFP members.Phylogenetic analysis classified soybean and Arabidopsis OFP proteins into five subfamilies ClassⅠ—Class V,of which soybean OFP family genes were mainly distributed in ClassⅠ and Class Ⅲ.The collinearity analysis revealed that 75 pairs of genes in the soybean genome had collinearity,four pairs of genes had tandem duplications,and only two genes,GmOFP-2 and GmOFP-39,did not have collinearity,which indicated that gene fragment duplication was the main reason for the increase in the number of soybean OFP family members.The expression patterns of GmOFP gene family members under drought stress and salt stress treatments were analyzed by qRT-PCR,and the results showed that,compared with the control,16 members out of 41 GmOFP genes exhibited significant differences in gene expression levels after drought treatments,with significant up-regulation of the expression of GmOFP-15,GmOFP-17,and GmOFP-32,while the GmOFP-4,GmOFP-5,GmOFP-6,GmOFP-9,GmOFP-12,GmOFP-21,GmOFP-23,GmOFP-25,GmOFP-26,GmOFP-27,GmOFP-38,GmOFP-39,and GmOFP-40 were significantly down-regulated after drought treatment.Eight members of GmOFPs showed significant differences in gene expression levels after salt treatment,among which GmOFP-7,GmOFP-14,GmOFP-31,GmOFP-32,GmOFP-36,and GmOFP-40 were significantly up-regulated,and GmOFP-1 and GmOFP-15 were significantly down-regulated.The above results suggest that the soybean OFP gene family may have important functions in response to drought stress and salt stress.

To reveal the mechanism of drought resistance of different resistant rice during germination period,Rice drought-sensitive materials(Calrose,Jingning 10,Shanxing 86)and drought resistance materials(Farry,Songjing 3,Ningjing 36)were studied on the effects of simulated drought stress(15% PEG-6000)on the growth index,physiological indexes and corresponding gene expression of different rice seeds.The results showed that under normal conditions,there were no significant differences in the expression levels of growth indicators and stress-related genes between drought-sensitive and drought-resistant cultivars.However,changes in physiological indicators were shown that there were no significant differences in the activities of superoxide dismutase(SOD) and peroxidase(POD),the contents of soluble sugar(SS) and hydrogen peroxide(H₂O₂) among different genotypes.The contents of malondialdehyde(MDA) and superoxide anion($\mathrm{O}_{2}^{\bar{.}}$) in the drought-sensitive cultivar Shanxing 86 were significantly higher than those in other materials,and the contents of catalase(CAT),proline(Pro) and soluble protein(SP) of drought resistant Ningjing 36 were significantly higher than those of other materials as well.Under drought stress,the relative germination potential(RGP),relative bud length(RSL),germination drought resistance index(GDRI)and vitality index(VI)of germinating seeds increased by 0.03—0.07 percentage,0.32—0.39 percentage,0.12—0.18 percentage and 92.41%—108.39%,respectively;MDA and reactive oxygen species($\mathrm{O}_{2}^{\bar{.}}$,H₂O₂) contents in germinating seeds of drought-resistant cultivars decreased by 2.54%—61.64%,19.60%—46.30% and 35.61%—62.02% respectively compared with drought-sensitive cultivars.The contents of osmotic regulating substances(Pro,SS,SP) increased by 5.93%—18.29%,1.08%—7.97% and 3.47%—6.03% respectively.The activities of antioxidant enzymes(SOD,POD, CAT) were increased by 17.29%—33.12%,15.24%—76.06% and 14.68%—18.61% respectively.The relative expression levels of OsP5CS,antioxidant enzyme synthesis genes (OsALM1, OsPOX1, OsCATC) were up-regulated by 2.66%—182.31% and 57.14%—513.27%,0.38%—109.06% and 63.39%—184.25% respectively.Comprehensive analysis showed that drought stress inhibited the germination of rice seeds and affected the physiological characteristics of seeds and the expression of corresponding genes during germination.Under drought stress,vigor index(VI),peroxidase(POD)and peroxidase synthesis gene(OsPOX1)are the key indicators affecting rice seed germination,whether it is drought-resistant or drought-sensitive materials.In addition to the above indicators,soluble protein(SP),proline synthesis gene(OsP5CS)and catalase gene(OsCATC)are other key indicators affecting drought-resistant materials.Relative shoot length(RSL),hydrogen peroxide(H₂O₂)and superoxide dismutase gene(OsALM1)are other key indicators affecting drought-sensitive materials.

In order to explore the photosynthetic physiological response mechanisms of three summer maize varieties (Xundan 20, Jinbei 288 and Dika 667) which were commonly cultivated in arid and semi-arid areas to drought stress, these three varieties were treated under different drought stresses (including non-drought treatment (CK), light drought (LD) and heavy drought (HD)). Responses of net photosynthetic rate to light intensity (Pn-PAR) and net photosynthetic rate to intercellular CO₂ concentration (A-Ci) were estimated by the portable photosynthesis system Li-6400, and responses of chlorophyll fluorescence parameters to light intensity were measured by portable modulation chlorophyll fluorescence meter MINI-PAM, respectively. The results were as follows. As for all these three varieties, the response modes of Pn and stomatal conductance (Gs) to PAR were similar among these three maize varieties, and the responses of Pn to Gs shifted to left along the drought stress gradient. The initial chemical efficiency (CE) and photosynthetic capacity (Amax) were significantly lower under heavy drought treatment than under the other two treatments for each of the three varieties. Compared with the results under CK treatment, the non-photochemical quenching coefficient (qN) and the quantum yield of the regulatory energy dissipation (Y (NPQ)) were lower and the quantum yield of non-regulated energy dissipation (Y(NO)) was higher under LD or HD treatment for the two varieties of Jundan 20 and Dika 667; and the photochemical quenching coefficient (qP) was lower under HD treatment for the variety of Jinbei 288. Compared with the results under CK treatment, the maximum net photosynthetic rate (Pmax) and initial quantum efficiency (AQY) were a little higher under LD treatment for the variety of Jinbei 288. Compared with the other two varieties, the Pmax and AQY showed higher tolerance to drought stress by keeping relatively lower qQ and lower Y(NO) for the variety of Jinbei 288, and these results not only showed the greater tolerance of Jinbei288 to drought stress, but also provided reference for the screening of crop varieties for drought tolerance.

In order to study the effects of continuous drought treatment in whole growth period on cotton growing development and final yield,in this experiment,pot-culture method was taken and Xinluzao 19hao,Xinluzao 27hao and Xinluzao 54hao as materials,the treatments were light and moderate drought stress,then measured morphological indexes,physiological indexes and photosynthetic parameters at seedling stage,bud stage,blooming stage and boll opening stage,and investigated yield components at harvest time.Results showed:cotton height and stem diameter decreased with the strengthen of drought stress; The content of reactive oxygen species and antioxidant enzyme activities were great difference at different growth stage,correlation analysis showed that there were significant or extremely significant correlation between active oxygen content and antioxidant enzyme activity,indicted that antioxidant enzymes activity changed regularly with the content of reactive oxygen species,so as to eliminate the excessive oxygen species in vivo and prevent the damage of reactive oxygen species; The photosynthesis of cotton at bud stage decreased with the strengthen of drought stress,but increased at boll opening stage,except Xinluzao 27hao which possibly due to persistent drought treatment caused the different developmental stage of cotton at later growth stage; Drought stress reduced the yield per plant and fiber length of Xinluzao 27hao and Xinluzao 54hao,light drought stress had little effect on single boll weight,even played a role in promoting; There were four indexes of cotton at blooming stage had significant correlation with yield per plant,indicted that cotton blooming stage might be the key period which easy to be affected by environment and determined the final yield.

In order to study the effect of drought stress on physiological characteristics of grafting flue-cured tobacco,using KRK26 as scion, KRK26,K326 and Anyan 2 as rootstock,analysing and discussing root morphology, plant morphology and physiological indexes of resistance in pot culture under different treatment. The results indicated that under drought stress conditions at early period, the relative content of chlorophyll (SPAD readings) decreased, while the content of proline, superoxide dismutase (SOD) activities, catalase (CAT) activities and peroxidase (POD) activities in flue-cured tobacco demonstrated an increasing trend. The root length,surface area,plant height,stem girth, node spacing and LAI of the grafted tobacco plants showed a decreasing trend,the content of proline continued to increase in both grafted seedlings and non-grafted seedlings with the aggravation of drought stress when tobacco leaves were turning to mature, whereas, the SPAD readings, SOD activities, CAT activities and POD activities all demonstrated a decreasing trend. The speed of decreasing in different root grafted was slower than that in own root grafted. Compared with KRK26/K326 and KRK26/KRK26, KRK26/Anyan 2 had greater parameters under drought stress, but the SPAD readings did not have significant difference. All the results showed that less damage was made to KRK26/Anyan 2 than KRK26/K326 and KRK26/KRK26 under drought stress, and KRK26/KRK26 suffered the most serious damage. According to correlation analysis, there was a certain correlation between morphological indexes and resistance indexes of grafting flue-cured tobacco. In conclusion, there were obvious differences among grafted tobacco in physiological characteristics, and there response to soil drought. The order of drought resistance was KRK26/Anyan 2, KRK26/K326 and KRK26/KRK26 in turn from strong to weak, based on the main root morphology,plant morphology,physiological characteristics under drought stress.

Drought stress has a serious effect on the growth and development of maize,which leads to a decrease of maize yield.Purple acid phosphatase is a phospholipase protein involved in many physiological and biochemical functions of plants.In order to further study the role of purple acid phosphatase family genes in the process of stress resistance of maize,this paper explored the response mode of ZmPAP26b gene under drought stress,and Real-time fluorescence Quantitavive analysis was used to analyze the relative gene expression in different maize inbreeding lines under simulated drought conditions;ZmPAP26b(GenBank:NC_050104.1)was cloned from maize,and PAP genes in Zea mays,Arabidopsis thaliana,Oryza sativa L.,Triticum aestivum L.,Sorghum bicolor and Brachypodium distachyon were identified and bioinformatic analysis was performed.Meanwhile,prokaryotic overexpression strains were constructed for functional verification.The results showed that the expression of this gene decreased in drought tolerant materials and increased in drought sensitive materials under drought stress.The CDS length of this gene was 1 431 bp,encoding 476 amino acids.A total of 228 PAP genes were found in six species,divided into 4 subfamilies by phylogenetic analysis.The 19 PAP genes in maize were distributed on 9 chromosomes and had similar conserved domains.Analysis of promoter cis-acting elements showed that they contained elements responding to drought and hormones.Prokaryotic expression experiments showed that the growth of strains containing the recombinant plasmid pET28a-ZmPAP26b was inhibited compared with non-loaded strains under 10% PEG-6000 and 15%PEG-6000 simulated drought stress.In summary,it is speculated that ZmPAP26b is negatively regulated under drought stress.

In order to clarify the effects of drought stress on the photosynthetic characteristics in flag leaf in the afternoon during grain filling stage and grain yield of winter wheat with different drought resistance,an experiment with two winter wheat cultivars and four water levels was conducted under the condition of rainproof pond cultivation in 2018—2019 and 2019—2020.The two winter wheat cultivars were Jinmai 47(JM47,strong drought resistance)and Yanzhan 4110(YZ4110,weak drought resistance).The four water treatments included severe drought(W1:65% MFC(maximum field water capacity)before sowing + 45%—55% MFC after jointing),moderate drought(W2:75% MFC before sowing + 55%—65% MFC after jointing),mild drought(W3:75% MFC before sowing+65%—75% MFC after jointing),suitable water supply(W4:75%MFC before sowing+75%—85% MFC after jointing).The net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO₂ concentration(Ci),transpiration rate(Tr),instantaneous water use efficiency(IWUE),maximum photochemical efficiency of PS Ⅱ (Fv/Fm)and actual photochemical efficiency of PS Ⅱ(ΦPS Ⅱ)in flag leaf from 14:00 to 16:00 during the early,medium and medium-late grain filling stage and the grain yield and its components at maturity were investigated.The results showed that both water and cultivars had significant effects on the photosynthetic and fluorescence characteristics in flag leaf in the afternoon during the grain filling stage and the grain yield at maturity of winter wheat.From the two-year average,compared with W4,the Pn,Gs and ΦPSⅡ in flag leaf in the afternoon during the grain filling stage under drought stress(W1,W2 and W3)respectively decreased by 2.07%—68.92%,-3.23%—50.00% and -1.89%—30.19% in JM47,and decreased by 7.71%—80.19%,11.11%—59.26% and 0—73.47% in YZ4110;the flag leaf Tr values in the afternoon during the medium grain filling stage in JM47 and YZ4110 respectively decreased by 6.30%—32.87% and 6.49%—41.74%,and the flag leaf Fv/Fm values in the afternoon during the medium-late grain filling stage decreased by 1.20%—18.52% and 2.50%—30.00%.In general,for all the above indexes,the decreasing amplitude for the same index was JM47<YZ4110.Compared with YZ4110,the Pn,Gs,ΦPSⅡ and Fv/Fm in flag leaf in the afternoon during the grain filling stage under drought stress(W1,W2 and W3)of JM47 respectively increased by 0.86%—64.89%,8.33%—36.36%,1.96%—184.62% and 1.25%—17.86%,and the grain yields of JM47 were respectively increased by 28.91%,8.06% and 5.40%.Except for IWUE,the flag leaf photosynthetic parameters in the afternoon during the grain filling stage were significantly and extremely significant correlated with grain yield,but the correlation indexes varied with variety and grain filling stage.For JM47,the correlation indexes between the grain yield and flag leaf photosynthetic parameters were highest for Pn,Gs and Fv/Fm during the medium-late grain filling stage,for ΦPSⅡ during the medium grain filling stage,and for Tr during the early grain filling stage.For YZ4110,the correlation indexes were highest for Pn,Gs and Tr during the early grain filling stage,for ΦPSⅡ during the medium grain filling stage and for Fv/Fm during the medium-late grain filling stage.In summary,drought stress decreased the photosynthetic function of flag leaf in the afternoon during grain filling stage and thus decreased the grain yield of winter wheat,the strong drought resistance variety could maintain better flag leaf photosynthetic characteristics in the afternoon during the grain the filling stage under drought stress condition,and significantly improved the ΦPSⅡ of flag leaf in the afternoon during the medium grain filling stage and the Pn,Gs and Fv/Fm of flag leaf in the afternoon during the medium-late grain filling stage,thereby increasing the grain yield.

In order to explore the effects of growth and aging characteristics of peanut under drought and salt stress,using Huayu 25 as material,potted experiment was carried out to study the change of peanut growth and aging characteristics due to the stress of drought and salt at flowering stage.The results showed that drought treatment (D),salt stress treatment (S),drought and salt stress (DS) increased the content of soluble protein,soluble sugar,free amino acid,proline,O₂^· and MDA. S treatment and DS treatment reduced the activity of SOD,POD and CAT in the leaves,which continued to decrease as time prolonged. But D treatment enhanced SOD and CAT activity in the leaves. After 10 days of rehydration,the content of soluble sugar,soluble protein,free amino acid,proline,O₂^· and MDA of D treatment reduced compared with the numerical values which detected before rehydration.D treatment had no significant difference with CK,including activity of SOD and POD and content of O₂^·,MDA,soluble sugar,free amino acid,proline. However,the difference of the activity of SOD,POD,CAT of DS treatment was significant compared with S treatment,so did the content of O₂^· and MDA.In the harvest time,single plant yield and the kernel rate of D treatment had no significant difference with CK,but DS treatment had significant difference with S treatment. Data from DAT9 showed that drought and salt stress had no significant interaction with soluble sugar,soluble protein,free amino acid and proline content in leaves. However,there was significant interaction of SOD,POD,CAT activity and O₂^·,MDA content between drought stress and salt stress. The interaction between drought stress and salt stress inhibited the activity of SOD,POD and CAT and exacerbated the peroxidation of plant cell membranes. Eventually it decreased the single plant yield and the kernel rate. Therefore,peanuts planting under salt stress should avoid the drought at flowering stage to reduce the harm of salt stress,drought stress and the interaction between salt stress and drought stress.

To study the physiological effects of different degrees of drought on soybean cultivars in different development periods. Two soybean cultivars with different drought resistances were taken as the experiment materials to study the effects of drought stress on the resistance index and physiological characteristics of soybean in different growth periods, and to explore the physiological mechanism of soybean response to different drought intensities at different developing stages in pot culture. Four treatments were set up:continuous mild drought stress (T1), continuous moderate drought stress(T2), drought stress in full seed stage (T3) and without drought stress(CK). The results showed that under drought stress, the chlorophyll contents of both soybean cultivars increased, and Jindazaochun 2 was more obvious at early stage, but it was less than that of Jinda 74 at grain-filling stage. Under continuous mild drought stress and continuous moderate drought stress, the MDA content of Jindazaochun 2 at different growth stages significantly increased, while the POD and MDA contents of Jinda 74 significantly increased under continuous moderate drought stress. At the branching stage, the content of reducing sugar in Jinda 74 decreased significantly during moderate drought. In the Granulation stage, the reducing sugar content of soybean leaves in Jindazaochun 2 was significantly increased, Jinda 74 was only reduced under drought treatment in the Granulation stage. At flowering stage, reducing sugar content reduced in Jindazaochun 2, but increased significantly in Jinda 74. It was found that drought had a great influence on reducing the plant height, node number, stem diameter of both cultivars. The decrease in plant height and stem diameter of Jinda 74 was more obvious. The resistance of Jinda 74 to drought was higher than that of Jindazaochun 2, which was related to the reduction of plant height and water consumption under continuous drought conditions. The results will provide a basis for comprehensive understanding of the soybean resistance to drought stress.

Tremendous impact of drought on agricultural production,research drought stress on physiological and yield,will provide the basis for soybean production in arid areas.In this paper,the use of plastic storage box drought stress test were studied photosynthetic physiology,leaf osmotic adjustment and antioxidant enzyme composition and biomass yield on the soil water into arid(45%-55% of the maximum water holding capacity of soil field) two horizontal and humid(80%-100% field soil water holding capacity,CK).The results showed that drought stress soybean net photosynthetic rate,stomatal conductance and transpiration rate decreased significantly,water use efficiency increased;drought stress on leaf peroxidase(POD) and superoxide dismutase(SOD) no significant effect on the content;malondialdehyde(MDA) content increased by 25.00% to reach a significant level;the amount of reducing sugars and total soluble sugars increased by 47.09% and 47.16%,respectively.Drought stress on soybean plant height,node number,stem diameter,aboveground biomass,yield decreased significantly.Under drought stress,soybean stomatal conductance decreased significantly,severely affected the supply of CO₂,reducing the net photosynthetic rate,so that the decline in soybean photosynthetic metabolism.Plant material can be adjusted to maintain the moisture permeation through the cell.Although soybeans can maintain cell moisture through osmotic adjustment substances,drought still inhibits normal plant growth and decreases soybean biomass and yield.

In order to understand the dynamic rules of sugars, starch, protein and trace elements of different types of wheat during grain filling stage under drought stress, and to identify the difference of nutriment between drought and irrigation in the process of grain-filling by high-yield wheat, high-quality wheat and water-saving wheat, the wheat varieties of Jimai 325, Jimai 418 and Jimai 323 in the North of Huang-Huai Region were used as experimental materials. The plants heading and flowering on the same day were selected for marking, and the grains of each variety were taken every 6 days after 7-31 days after anthesis. The effects of drought during grain filling on the contents of total soluble sugar, sucrose, glucose, fructose, protein, Fe, Zn, Mn, Cu, amylose and amylopectin accumulation, starch accumulation rate and the activities of key enzymes in starch synthesis were studied. The results showed that the content of sucrose and glucose in wheat grains was significantly decreased under drought stress, and the effect on fructose content was relatively small, and the sucrose and fructose of high-yielding variety Jimai 325 were less affected by drought in the filling process. Drought stress decreased the content of amylopectin and total starch in wheat grains, but had relatively little effect on the content of amylose. The effect of drought stress on starch content of high-yield and high-quality varieties was significantly greater than that of drought-tolerant variety Jimai 418. The activity of starch synthase was increased in the early and middle stages of filling stage under drought stress, and decreased rapidly in the middle and late stages compared with irrigation control. The content and accumulation of four mineral elements in wheat grains were Mg>Fe>Zn>Mn. With the progress of grain filling, the content of trace elements showed a downward trend. The accumulation of Fe, Zn and Mg in grains of Jimai 325 was higher. The difference of nutrient accumulation in grain filling process of different types of wheat under drought conditions were studied to provide theoretical data and reference basis for optimizing cultivation measures and realizing high quality, high yield and water saving of special wheat.

In order to explore a fast and efficient way to screen drought-resistant varieties of winter wheat, and to select drought-resistant winter wheat varieties. Six winter wheat varieties, Yannong 999, Taimai 1918, Jimai 22, Jimai 23, Taishan 27 and Shiluan 02-1 were used in this study. Normal water treatment(75% relative soil water content), mild drought treatment(55% relative soil water content) and moderate drought treatment(40% relative soil water content) were arranged to explore the chlorophyll fluorescence parameters, biomass, root-shoot ratio, SPAD, superoxide dismutase(SOD) activity, malondialdehyde(MDA) content and their correlations. Results showed that, compared with other varieties, under drought stress, Taimai 1918 obtained the highest drought resistance coefficient(DTC). The smallest reduction of root to shoot ratio, SPAD value, photosystem Ⅱ maximum photosynthetic efficiency(Fv/Fm), photosystem Ⅱ actual photosynthesis efficiency(φPSⅡ), relative electron transfer rate(ETR), SOD, and the largest increasing in non-photochemical quenching(NPQ) and minimal increasing in MDA content were observed in Taimai 1918. The order of drought resistance of 6 winter wheat varieties was Taimai 1918 > Yannong 999 > Jimai 22 > Jimai 23 > Taishan 27 > Shiluan 02-1. The chlorophyll fluorescence parameters were significantly correlated with drought resistance coefficient, SOD activity and MDA content. Sum up, the drought resistance in Taimai 1918 was strongest, and chlorophyll fluorescence parameters can be used for screening drought-resistant winter wheat varieties at seedling stage.

In order to clarify the drought resistance and drought resistance mechanism of Allium polyrhizum in Inner Mongolia grassland,potted water control method was adopted.Two gradients were set,75% of the maximum field water capacity as the control(CK),and 25% of the soil relative water content under 30 days of drought stress.The root morphology,physiological characteristics and leaf photosynthetic characteristics of Allium polyrhizum from different sources were analyzed under drought stress. The result showed that Allium polyrhizum in Siziwang Banner compared with the Chifeng and Ordos was remaining relatively high root surface area,root volume and root length 0-0.5 mm in diameter. Allium polyrhizum root growth was relatively less affected by drought stress,chloroplasts were relatively stable and strong drought resistance in Siziwang Banner. Drought stress significantly decreased the above ground biomass,below ground biomass and total biomass of Allium polyrhizum in Chifeng and Ordos,but had no significant effects on Siziwang Banner(P>0.05). The Pn,Tr,Gs,Ci and leaves relative water content of Allium polyrhizum seedlings were significantly decreased and the relative permeability of cytoplasmic membrane was markedly increased under the whole drought stress treatment. Drought stress induced stomatal closure of Allium polyrhizum leaves and reduced transpiration to decrease water loss.The root characteristics,relative water content,chlorophyll and photosynthetic characteristics of Allium polyrhizum in different sources were certain differences under the same treatment. In general,the effect of drought stress on Allium polyrhizum in Siziwang Banner was relatively weak,it was indicating stronger drought tolerance.

In order to explore the genetic basis of drought resistance and guide drought resistance breeding, mapping of QTL associated with drought resistance at germination stage of foxtail millet was done. An F₂ segregating population was constructed using 100 individuals derived from a cross between Shanxi 2010 and K359×M4-1. A genetic linkage map was constructed based on 2b-RAD sequencing, which was then combined with the phenotypic trait of drought resistance for QTL mapping. The results showed that drought resistance at germination stage of foxtail millet was a complex quantitative trait and controlled by multiple genes. A genetic map containing 583 SNP makers was constructed by 2b-RAD of parents and F₂ population. The map covered 9 chromosomes of foxtail millet, with an average number of 64.8 and an average genetic distance of 0.97 cM between markers. A total of 3 QTLs were identified:qSIDR-5a, qSIDR-6a and qSIDR-6b, located in foxtail millet chromosome 5 and 6, respectively, which explained 12.4%-14.3% of phenotypic variation. Among them, phenotypic contribution rate of qSIDR-5a was the highest, which explained 14.3% of phenotypic variation. These QTLs were not included in the same chromosome interval as the identified drought resistance related QTLs of foxtail millet, and thus were described as new candidate gene loci associated with germination stage drought resistance.These QTLs can be used for fine mapping and gene cloning, as well as molecular regulation mechanism of drought resistance of foxtail millet.

The purpose of this study was to explore the effects of different drought stress levels on maize growth traits and yield in the semi-arid region of Northeast China, and to lay a theoretical foundation for further research on the physiological mechanism of maize drought resistance.Three kinds of maize varieties with different drought tolerance were selected and five water gradients of normal water supply(CK), light drought(LS), moderate drought(MS), severe drought(SS)and lethal(S)were set at maize jointing, tasselling and filling stages, respectively. The effects of different drought stress on the growth traits and yield related indexes of three maize varieties were comprehensively analyzed. The plant height, ear position and dry matter weight of maize decreased with the increasing of drought degree, but the stem diameter had no significant difference with the increasing of drought degree. The plant height, ear position and dry matter accumulation of maize variety Jinqing 707 was the highest, followed by Nendan 19 and Fudan 16. During tasselling stage, the spike characters of maize changed most obviously under drought stress, and the maize yield was the lowest under severe drought, and no yield under continuous drought.Under the same drought degree, the worse the drought tolerance of maize varieties, the greater the yield reduction. The specific performance of maize yield is Jinqing 707 > Nendan 19 > Fudan 16.A comprehensive analysis of multiple indicators shows that tasselling stage is the key period of water requirement of maize, which is easily affected by drought stress. At the same time, it is pointed out that drought stress or serious degree of drought stress in tasselling stage is the main factor leading to the decrease of maize yield.

Chalcone synthase(CHS)is the initial and crucial enzyme in the flavonoid biosynthesis pathway,responsible for the synthesizing of metabolites such as flavones,flavonols,isoflavones,and anthocyanins,which play a vital role in enhancing plant stress resistance.In order to explore the role of CHS genes in the drought stress response of oat seedlings,it identified a CHS gene from the full-length transcriptome data of oats,named AsCHS.Gene cloning,bioinformatics analysis,subcellular localization,and expression pattern analysis were conducted.The results showed that the AsCHS gene encoded a protein composed of 398 amino acids and had a CHS family-specific tag sequence.This protein was hydrophobic and unstable.It was a non-transmembrane protein and was located in the nucleus and cytoplasm.Secondary structure prediction showed that AsCHS was mainly composed of α-helices and random coils.The analysis of the cis-acting elements within the promoter region revealed that the gene contained cis-elements associated with drought stress response and multiple hormone signaling pathways.Phylogenetic tree analysis showed that AsCHS was closely related to its counterparts in Lolium perenne,Poa annua,and Deschampsia antarctica.Subcellular localization indicated that the AsCHS protein was localized in the nucleus and cytoplasm.Compared with the control group,the expression pattern of AsCHS in oat seedlings under drought stress changed from fluctuating expression to incremental expression with different germination time,shifting from the highest expression level in roots to the highest in leaves,with significant differences observed in leaves expression.It laid a foundation for elucidating the function of AsCHS in the drought stress response of oats.

Tiller-related traits are important characteristics of wheat plant type,which determine plant structure and affect grain yield.In order to understand the inheritance and drought resistance of tiller-related traits in wheat under different water conditions,and to excavate the loci related to tiller-related traits,240 wheat varieties (lines) were selected as the subjects of this study,based on the phenotypic identification of tiller angle,effective tiller number and yield per unit area under normal irrigation (NI) and drought stress (DS) conditions,and the comprehensive evaluation of drought resistance,combined with 90K gene chip,genome-wide association study (GWAS) was to identify genetic loci for tiller-related traits and to screen for superior germplasm.The tiller angle,effective tiller number and yield per unit area showed significant difference,and the coefficient of variation ranged from 0.07 to 0.33.According to D-value,the drought resistance of Zhongyou 206 was the best.A total of 54 stable genetic loci significantly associated with tiller angle and other traits were detected, distributed on all chromosomes except 3D, 4D and 5D. Three identical stable loci were commonly detected under both treatments, located on chromosomes 2B, 4B, and 6B. Additionally, four pleiotropic loci were commonly detected in different traits, located on chromosomes 2B, 2D, and 5B.At the same time,the haplotype analysis of Ra_c491_902 (R²=5.45%—17.91%),which was significantly correlated with tiller angle on chromosome 2B,showed that there were three haplotypes:TA-Hap1,TA-Hap2 and TA-Hap3,the haplotypes (lines) containing TA-Hap1 were mainly derived from Huanghuai winter wheat regain.Five candidate genes related to tiller angle were screened by screening the stable genetic loci detected under different treatments.Gene annotation of the genes selected on Ra_c491_902 showed that the genes encoding cytochrome P450 family protein can be used as important genes such as regulating tillering angle,plant drought resistance and defense,to explore the association between genes and phenotype,and lay the foundation for the genetic improvement of tiller-related traits in wheat.

In order to explore the effect of grain size and sowing depth on emergence and seedling growth,determining suitable grain size and sowing depth in mechanization of summer maize production of Southwest Hilly Area.In the split-plot design,using Zhenghong 505 as the test material,3 kinds of grain size was assigned to the main plot,and 3 sowing depth(2,6,10 cm) to the subplot,emergence rate of maize,seedling quality,yield and yield components have been investigated in drought condition.The results showed that compared with small grain,large grain had higher emergence rate,the seedling was more haleness and grew better in drought,and there was a certain effect of increasing yield ultimately;Shallow sowing(2 cm) was conducive to the emergence,and the growth vigor of the seedlings of 6 cm sowing depth was best just when emerging,then the 10 cm depth of the seedling grew gradually strong,and obviously better at the 5 leaf period(large and medium grain)-7 leaf period(small grain) than shallow sowing treatment,which also showed a certain increase in yield.Therefore,in the dry land or dry season,choosing large grain and suitable sowing depth in maize production can effectively better sthong seedlings,improve the resistance of drought,and achieve the purpose of producing income insurance.

A Receptor-like kinase(RLK)gene, OsSIK1,plays important roles in drought stress-tolerance in rice,through the activation of the antioxidative system.To make maize plants have much more drought resistance genes and further to obtain drought tolerance maize germplasm.In this study, OsSIK1 gene of rice was transformated into maize inbred Zheng 58 plants by pollen-mediated method.First,transgenic plants in T₁,T₂ and T₃ were detected by Kanamycin resistance screening,PCR and Southern Blotting,transgenic plants were obtained from T₁ and pure transgenic lines was obtained from T₃.Next,drought resistance analysis to transgenic maize plants and non-transformation control plants were conducted under the condition of 16.1% PEG drought stress.The results showed that compared with non-transgenic plants,the seedling leaf relative water content,chlorophyll content and SOD activity of transgenic plants were increased by 7.4%-19.8%,11.3%-106.9% and 45.8%-93.4%,respectively;furthermore,the relative conductivity and MDA content were decreased by 35.4%-58.1%,and 25.7%-50.4%,respectively.All the physiological indexes under the drought stress proved that transgenic OsSIK1 gene improved the drought resistance of transgenic maize plants,further analysis found that there were significant differences on drought tolerance between 5 transformed lines and their control groups,and their performance of field were superior to that of non-transgenic maize seedlings.At last,5 transgenic maize inbred lines were obtained,which suggested that genetically modified maize has improved the drought resistance by introducing foreign OsSIK1 gene of rice.

This study provides a good foundation for further elucidating the function and mechanism of AhPLDα1 and AhPLDα2 in responding to drought stress in peanut.The full-length CDS sequences of AhPLDα1 and AhPLDα2 were cloned from Jihua 4 peanut leaf with ABA treatment using RT-PCR.The AhPLDα1 and AhPLDα2 gene fragments were inserted into the expression vector pBar-F3 by forward ways.These constructs were transformed into Agrobacterium tumefaciens GV3101 by freeze-thawing method and then introduced into wild-type Arabidopsis thaliana using modified floral-dip method.Under the condition of drought,the authors observed phenotypic changes of wild type and transgenic plants.Colony PCR and enzyme digestion results showed that,the plant overexpressing recombinant plasmid pBar-AhPLDα driven by CaMV35S promoter was successfully constructed.Glyphosate resistance screening,PCR detection and gene expression analysis showed that the positive transgenic plants were obtained.Under water deprivation,overexpression of AhPLDα1 and AhPLDα2 in transgenic Arabidopsis plants resulted in significantly enhanced tolerance to drought stress.In conclusion, AhPLDα1 and AhPLDα2 have a certain relation with drought stress signal transduction in transgenic Arabidopsis plants,and are potential candidate genes on the way to modified crop drought resistance.

bZIP transcription factors are widely found in plants and play an important role in regulating plant growth and development and abiotic stress response.In order to explore the functional role of bZIP transcription factor in maize drought stress response,transcriptome sequencing technology was used to analyze the expression changes of transcription factors in maize seedlings treated with drought stress for 5 days and rehydration for 3 days,and a bZIP transcription factor(ZmbZIP26)was screened from transcriptome data in response to drought and rewatering treatment.Co-expression network analysis revealed that ZmbZIP26 was at the core node of network regulation.The gene contained a 558 bp open reading frame encoding 185 amino acids,which was a hydrophilic protein.Phylogenetic tree and conserved sequence analysis showed that ZmbZIP26 protein had high homology with homologous proteins of sorghum and Miscanthus,and also had the same conserved motifs at the same amino acid positions.Cis-element analysis showed that the upstream 2 000 bp region of the ATG site contained drought response elements,hormone response elements and light response elements.qRT-PCR analysis showed that ZmbZIP26 was a constitutively expressed gene,which was highly expressed in young stems,female panicles and roots.ZmbZIP26 positively responded to drought,high temperature,high salt and nitrogen stress and the process of restoring,which might play an important role in the process of plant resistance.Subcellular localization analysis revealed that ZmbZIP26 was a nuclear protein localized in the nucleus.Protein interaction prediction showed that ZmbZIP26 might interact with zinc finger protein,serine protein,Ca-dependent protein and glutathione transfer protein to construct a regulatory network,which cooperatively regulated maize growth and development and stress response process.

Calcium-dependent protein kinases (CDPKs) function as Ca²⁺ sensor in various plant physiological processes.CPK10 was one member of CDPK family.In order to investigate the molecular mechanisms of CPK10 and it's high homology CPK30 in response to stress,cpk10×cpk30 double mutant was firstly constructed.The phenotypes in response to various stress were detected,and the RT-PCR method was used to analyzed the two genes expression.The results showed that there was no difference in the seed germination stage between double mutant and wild-type plants in the treatment of drought,salt and ABA.In the mature stage,double mutant exhibited no difference to drought stress compared with wild-type and single mutant.Nevertheless,the expression levels of RD29A was decreased in the double mutant and showed opposite trend in wild-type and single mutant during drought stress.The expression of ABA-responsive gene OST1 was enhanced obviously in double mutant after drought stress 0.5 h.The cpk10×cpk30 double mutant was successfully obtained.Our data indicated that CPK10 and CPK30 might be involved in ABA-dependent signal transduction pathway,and showed redundant functions.

Foxtail mille is a C₄ gramineous crop with drought resistance, barren-tolerance, wild adaptability and high adverse resistance. To reveal the role of the genes expression characteristics under light and stress of foxtail millet, the genes related to abiotic stress were explored in this experiment. A PPDK gene, named as SiPPDK2, was identified in foxtail millet genome by bioinformatics method. SiPPDK2 was located on chromosome 3 in foxtail millet genome, which contained 18 introns. It contained 3 transcripts and primary alternative transcript encoding 945 amino acids residues. Subcellular localization predictions indicated that SiPPDK2 was mainly localized in chloroplasts. Functional domain and multiple sequence alignment analysis revealed that SiPPDK2 protein had a more closely relationship with PPDK proteins in maize, sorghum and rice. RT-PCR analysis showed that the expression of SiPPDK2 at its seedling stage was induced by PEG, ABA, salt and low temperature treatments. Further studies indicated that SiPPDK2 was involved in drought stress and different light intensity at the jointing, heading and filling stage, in which the expression was significantly increased under the drought condition at heading and filling stages and under the low light condition at jointing and filling stage. cis-elements analysis revealed that hormonal, stress, light, and other growth-related responses cis-elements were present in the promoter region of the SiPPDK2. The results speculated that SiPPDK2 is involved in the response to abiotic stress in foxtail millet.

To identify the miRNAs and their response regular patterns to salt stress and drought stress,rice seedlings at three leaves stage were used to quantify the expression of miRNAs and their targets when treated with salt and drought stresses at 0,3,6,12,24,48 h by qRT-PCR. The results demonstrated that expression patterns of miRNAs were affected by space-time and tissues under salt and drought treatments. Further analysis indicated that the expressions of miR156,miR164,miR167,miR169, and miR171 upregulated in roots with time and expressions of miR159,miR160,miR319,miR398, and miR1848 downregulated at 3 h and then upregulated when treated with salt(NaCl). And the 10 miRNAs were performed their lowest expressions in shoots at 3 or 6 h under NaCl treatment. On the other hand,the expressions of the most of the 10 miRNAs downregulated in roots generally and expressions of miR156,miR159 and miR160 downregulated in shoots and the expression patterns of miR167,miR169,miR319,miR398, and miR1848 down regulated first and then upregulated when treated with drought(PEG). Furthermore,expression patterns of targets were also affected by space-time and tissues. And only few expression patterns of the 10 miRNAs negatively correlated with its target,which implied the complexity of the regulation network of miRNA and its target in response to stresses.

To provide one elite drought-resistance gene resource for maize breeding program,a trehalose-6-phosphate synthase(TPS) gene sequence was obtained from Gossypium arboretum by bioinformatics analysis and molecular experimental operation. The gene was optimized and synthesized based on maize preferred codons. Afterwards,the gene was cloned into expression plasmids by multiple DNA restriction enzyme digestion and molecular ligation operations,and further transformed into E.coli and yeast cells to identify its expression status. Finally,the new TPS gene was cloned into plant expression vector. The results showed that the new synthesized gene had 2 586 bp in length,it contained a whole open reading frame and encoded 861 amino acids;constructed prokaryotic and eukaryotic expression plasmids can agree with our predicted results,this suggested that the gene could be used for cell transformation experiment;the synthesized TPS gene could effectively express trehalose-6-phosphate synthase in E.coli and yeast cells;the TPS gene was successfully ligated into plant expression vector pCAMBIA-2300,and further transformed into engineering strain LBA4404 of Agrobacterium. Comprehensively,it was concluded that a new TPS gene was obtained in this experiment,which could express trehalose-6-phosphate synthase in prokaryotic and eukaryotic cells. Therefore,the constructed plant expression plasmid can be directly applied in maize drought-resistance breeding program.

To elucidate the molecular mechanisms underlying peanut pod responses to water stress,this study employed pot experiments combined with transcriptomic analysis.Using well-watered conditions as the control, we systematically investigated the effects of periodic drought and waterlogging stress during the flowering-pegging stage on yield,quality,and gene expression in peanut pods. Results demonstrated that both drought and waterlogging stresses significantly reduced peanut pod yield(by 26.43% and 77.69%,respectively)and crude fat content in kernels (by 9.46, 6.71 percentage points,respectively).Transcriptomic analysis further revealed 1 525 and 1 382 differentially expressed genes(DEGs)in the drought-stress and waterlogging-stress groups compared to the control, respectively, with down-regulated expression being predominant in both sets of DEGs. Specifically, drought stress suppressed six key metabolic processes related to lipid and fatty acid metabolism in peanut pods,with 88.38% of associated genes showing downregulated expression,indicating that lipid metabolic disruption may be the primary cause of yield and quality reduction under drought. Waterlogging stress predominantly interfered with pod metabolism and defense functions by downregulating genes associated with catalytic activity,transmembrane transport,redox reactions,and biosynthesis of secondary metabolites.Moreover, KEGG enrichment analysis indicated that metabolic pathways and biosynthesis of secondary metabolites were significantly affected under both water stress conditions. Key gene validation via qRT-PCR corroborated the RNA-seq data, confirming the reliability of the transcriptomic findings. In summary, this research elucidates the molecular basis of peanut pod response to water stress at the transcriptome level, demonstrating that lipid metabolic disruption is the primary factor underlying yield reduction and quality deterioration under drought stress, whereas peanut pods mitigate the adverse effects of waterlogging mainly by modulating the expression of genes associated with redox homeostasis and metabolic pathways.

Metacaspase (MC) belongs to arginine/threonine specific protease,studies have shown that it plays a role in programmed cell death.To investigate the distribution of MC family genes in the genome of Brassica napus and whether they respond to drought stress,this study systematically analyzed the physicochemical properties,phylogeny,gene structure,conserved domains,cis-acting elements,and expression patterns of MC family genes under drought(PEG6000)and abscisic acid(ABA)stress in B.napus.A total of 25 BnMC genes were identified.Chromosomal localization showed that the 25 BnMCs were distributed on 13 chromosomes.Subcellular localization prediction showed that 17 members of the BnMC family were localized in the nucleus and seven members were in the cytoplasm.The phylogenetic tree classified BnMC into two major classes (Type Ⅰ and Type Ⅱ) and four branches (Group A,Group B,Group C,and Group D).BnMCs of the same branch had similar gene structure and conserved motif distribution.The core promoter regions of BnMC contained four types of cis-acting elements:light response element,phytohormone response element,plant growth and development response element and stress response element.Among all the cis-acting elements related to abiotic stress responses,the abscisic acid response element (ABRE) was the most abundant,with a total of 79.All members contained this cis-acting element.The transcriptome sequencing revealed that the expressions of BnMC10,BnMC22,BnMC1,BnMC12 and BnMC8 were up-regulated and the expressions of BnMC4 and BnMC5 were down-regulated after drought treatment.The qRT-PCR assay showed BnMC10,BnMC8,BnMC1 and BnMC12 genes were expressed in both roots and leaves and were up-regulated by both PEG6000 and ABA,with BnMC1 showing the most significant up-regulating changes.In summary,the response of B.napus to drought stress involves the regulation of the expression level of MC family genes.

In order to explore the effect of plastic film mulching on the growth and yield of millet, clarify the mechanism of plastic film increase production, and provides theoretical basis for the whole film dibbling technology in the summer crops, a study on influence mechanism of film mulching on growth development and yield had been conducted. The test using spit plot experiment design was executed in Shijiazhuang luancheng Qiema experimental station, 2015. The main plot had two treatments, respectively is plastic mulch and no plastic mulch. The split plot had three varieties, respectively is Jigu 19, 36 and 38. Under the condition of plastic mulch and no plastic mulch, the morphological characteristics, yield and its traits, flag leaf SPAD values and flag leaf net photosynthetic at heading stage millet rate were studied. Results show that:compared with no plastic mulch, the sum area of top three leaves increased 12.83-26.36 cm², chlorophyll SPAD value increased 8.2%-17.1%, net photosynthetic rate increased 34.9%-34.9%, and yield increased 7.3%-10.8%. Yield performance of Jigu 36 was better than Jigu 19 and Jigu 38, and yields of three varieties (especially Jigu 38) were improved by film mulching. Yield had a significantly positive correlation with 2nd top leaf area, net photosynthetic rate, leaf area and the top three leaves area. Flag leaf area was positively correlated with grain weight per ear and ear length. Therefore, the growth and developing physiological stage of top leaves (especially 1st top leaf), film mulching affected the growth of ear and increased millet yield eventually.

This study investigated the impacts of drought on the agronomic,physiological,and biochemical characteristics of peanuts developed a classification methodology for drought resistance,screened the varieties of peanut with drought resistant.Agronomic traits of 27 peanut germplasms under drought stress were measured 30 days after sowing,and drought resistance was graded by correlation analysis,principal component analysis,cluster analysis,and membership function method.Drought-resistant peanut JNH3,intermediate L231,and drought-sensitive L236 were selected for determination of physiological and biochemical indexes and microstructure observation,and different drought-resistant peanut germplasms were identified.The results showed that after drought treatment,the decrease in main stem height ranged from 2.26% to 34.06%,the length of first branches decreased from 1.11% to 57.20%,the main stem base coarse decreased from 1.54% to 38.36%,and the root-shoot ratio decreased from 65.01% to 92.83% under different environments.According to the comprehensive weighted membership function,peanut materials were grouped into three types:drought-resistant,intermediate,and drought-sensitive.Among them, the above-mentioned traits of the intermediate type and the drought-sensitive type peanuts reached a significant level compared with the control. Under drought stress,ROS in functional leaves of peanut increased,and different expressions of ROS were found by NBT and DAB staining,among which NBT and DAB staining were JNH3,L231,and L236 from light to deep,conforming to the classification of drought resistance type.Compared with the control,the POD activity of JNH3,L231,and L236 increased by 42.71%,26.04% and 20.59% respectively,among different varieties,and CAT activity trend was consistent with the above.The SOD activity of JNH3,L231,and L236 increased by 48.01%,63.49% and 73.15% respectively,among different varieties,and the MDA activity trend was consistent with the above.The proline content of JNH3,L231,and L236 was increased by 1.1,1.07 and 1.03 times,and the soluble sugar content of JNH3,L231,and L236 was increased by 44.06%,31.54%,and 38.62% respectively,among different varieties.Under drought stress,peanut root growth was limited,the total root length and total root area were significantly reduced,the root tip cells were partially necrosis,and the degrees were shallow to deep in JNH3,L231,and L236 respectively.

Aquaporins are channel proteins, which located in biological membranes including plasma membrane and tonoplast.It can highly facilitate water transportation across biological membranes.To investigate molecular mechanism of water regulation during seed germination, a tonoplast intrinsic proteins(TIPs)gene fragment TIP4;1 was isolated from Brassica napus seed by RT-PCR.The expression ofTIP4;1 gene during seed germination and stresses treatment was analyzed by quantitative Real-time PCR(qRT-PCR).The transcription levels of TIP4;1 was analyzed during germination, and these results showed TIP4;1 expression levels was scarcely detected in dry seed, but was up-regulated during germination as well as early young seedlings.In addition, expression of TIP4;1 in response to abiotic stress was investigated, and results showed that TIP4;1 gene expression was upregulated under drought, cold and salt stress, suggesting that TIP4;1 may be involved in Brassica napus seed germination and stress response process.Aquaporin regulation mechanism would be further revealed in future, which had realistic significance for solving drought and salt stress problems.

To study the expression of grape stress tolerance gene (CAN70200.1),a 1 354 bp promoter fragment (named as P_CAN) upstream of the gene CAN70200.1 was isolated by using PCR technology.Promoter sequence was analyzed by the database of PlantCARE and PLACE.The result showed that the P_CAN sequence contained basic elements CAAT-box,TATA-box and some cis-acting elements that response to abiotic stresses,light and plant hormones.To verify the expression pattern of the promoter,the P_CAN fragment was fused with GUS reporter gene located on pCAMBIA1391Z to construct a plant expression vector p1391Z-CAN,followed by transformation into tobacco by Agrobacterium-meditated method.The expression activity of P_CAN promoter reached highest at 120 min after drought stress treatment or at 30-60 min under 4℃ cold treatment condition,indicated that the P_CAN promoter could express under the condition of treatments with cold and drought.

In order to reveal the protective mechanism of exogenous Brassinolide on the photosynthesis of maize seedlings under drought stress,this experiment used the Zhuyu 309 as test materials and adopted the solution culture method,studying the changes of growth parameters,chlorophyll content,photosynthetic parameters,chlorophyll fluorescence parameters and D1 protein content of maize seedlings that used 20% PEG-6000 to simulate drought stress after exogenous Brassinolide (BR) pretreatment. Compared with that of drought stress,the results of corn seedling which after the BR pretreatment showed that its height increased by 45.87%,the root length increased by 20.56%,the total dry matter accumulation increased by 8.01%,the relative water content increased by 4.50%,chlorophyll a content increased by 26.32%,and photosynthetic parameters (Pn,Gs,Ci,Tr) increased by 9.57%,38.23%,30.19% and 28.12% respectively,the activity of photosynthetic system Ⅱ (Φ_PSⅡ) increased by 20.48%,and the maximum photochemical efficiency increased by 0.66%. Photosynthetic system Ⅱ absolute electron transport rate (ETR (Ⅱ) and the relative electron transport rate of photosynthetic system Ⅱ(rETR(Ⅱ)) were increased by 20.40% and 31.02% respectively. The content of D1 protein increased by 37.34% (P <0.05). The results showed that BR treatment under drought stress condition could improve the growth and development of maize seedlings,alleviate the damage of photosynthesis system,promote the stability of D1 protein and improve the adaptability of maize seedling to drought stress.

WRKY transcription factor plays an important role in plant response to abiotic stress and regulation of resistance gene expression. In order to reveal the role of a soybean transcription factor GmWRKY58 in response to abiotic stresses.The full length of GmWRKY58 cDNA was cloned from soybean,and the amino acid sequence,physiological and biochemical characteristics and evolutionary relationship were deduced. Subcellular localization and the changes of gene expression under different tissues and abiotic stress were studied. The results showed that GmWRKY58 had a 954 bp length open reading frame and encoded a total of 317 amino acids. Subcellular localization results showed that GFP signals combined GmWRKY58 was only detected in the nucleus. Real-time RT-PCR analysis showed that GmWRKY58 was expressed in soybean roots,stems,leave,flowers and pods,and the expression in each tissue of roots,stems and leave was significantly higher than flowers and pods. In soybean roots, GmWRKY58 gene can be significantly induced by abiotic stress factors such as high salinity,drought,low nitrogen and iron deficiency.Under high salt stress, GmWRKY58 gene expression was increased by more than 187.4 times. Moreover,this gene just slightly induced by other abiotic stresses shch as SA,low temperature,low phosphorus and low potassium. The results indicate that GmWRKY58 plays an important regulatory role in abiotic stress process of salt,drought,low nitrogen and iron deficiency in soybean.