Identification Of Drought Resistance And Identification Of Transcription Factors Related To Drought Resistance Of Barley Germplasm Resources

Qingke(Hordeum vugulare L.var.nudum Hook.f)is the most important food crop in the Tibet Autonomous Region,with its planting area and total yield accounting for more than 75% of the region’s food crops,55% of the national Qingke planting area and 67% of the total yield.In recent years,due to the gradual deterioration of natural conditions for crop growth,the normal growth environment of crops has been affected,resulting in crop yield and quantity reduction.Drought is one of the most common stresses in crops.Drought directly leads to a decline in photosynthesis,accumulation of reactive oxygen species,and damage to cell membranes,ultimately leading to a significant decline in yield and quality.Drought is the natural factor that has the greatest impact on crop growth and development besides the genetic factors of the crop itself.Currently,under the increasingly harsh natural environment,exploring,researching,and utilizing drought resistance resources contained in Qingke germplasm and studying the molecular mechanism of drought resistance germplasm have important theoretical significance and practical value for Qingke drought resistance research and breeding.In this study,1374 Qingke germplasms were used as research materials.Based on different levels of drought stress,PEG was used to simulate drought stress and identify their drought resistance.Transcriptomic analysis based on DNA affinity purification and sequencing identified novel transcription factors(TF)that are key to drought resistance in Qingke,and preliminary verification of gene function was performed using RT-q PCR.The research results are as follows:In this study,1374 Qingke varieties were used as research materials,and PEG was used to simulate drought stress.The remaining experimental conditions were consistent except for drought stress.The focus was on morphological indicators such as plant phenotypic agronomic traits,plant height,aboveground growth,and aboveground fresh and dry quality,as well as physiological characteristics changes of different resistant materials under stress environments,mainly including leaf wilting,yellowing,curling,and stem lodging.According to the results of aboveground biomass characteristics,there were significant differences in the growth and physiological characteristics of different Qingke varieties under 20% PEG solution stress(P<0.05).The top 50 varieties with drought resistance characteristics were selected: B14,QB14,ZDM5616,ZDM5617,ZDM5618,ZDM5622,ZDM5626,ZDM5640,ZDM5653,ZDM5669,ZDM5666,ZDM5675,ZDM5696,ZDM5700,ZDM09817,Zang 0120,Zang 0124,Zang 0126,Zang0221 Zang 0225,Zang 0226,Zang 0234,Zang 0235,Zang 0236,Zang 0240,Zang 0241,Zang 0242,Zang 0243,Zang 0247,Zang 0253,Zang 0254,Zang0256,Zang 0257,Zang 0278,Zang 0314,ZYM2183,ZYM2198,Kunlun 8,Beiqing 3,Kangqing 3,Kangqing 7,Xila 3,Xila 10,Xila 15,Zang 148,Zang336,Zang 690,Zang 3179,Zang 7239,Zang 1265;The top 50 varieties sensitive to drought: WDM3208,QB23,WDM06276,ZDM04080,Kunlun 12,C1,ZDM5587,ZDM5601,ZDM5684,ZDM5734,WDM02114,WDM03140,WDM03156,WDM03157,WDM03164,WDM03282,WDM0329,WDM03369,WDM03370,WDM03371,WDM03376,WDM03331,WDM03339,WDM03276,WDM03285,WDM0325 1.WDM03255,Zang0343,Zang 0344,Zang 0345,Zang 0350,Zang 0385,Zang 0386,Zang 0434,Zang 0443 Zang 0449,Zang 0450,Zang 0452,Zang 0653,Zang 0657,Zang0678,Zang 0695,Zang 0703,Zang 0714,Zang 0840,Zang Qing 3000,Lhasa Goumang,Canada 368,Zang 1290,Zang 1331.2.Identification of key novel transcription factors(TF)for drought resistance in Qingke through transcriptome analysis based on Dap-seq(DNA Affinity Purification Sequencing).The experimental design includes two Qingke germplasm;Drought resistance: Himalayan No.10(X)and drought sensitive: Tibetan Qing3000(W)were both exposed to T1(four hour short-term treatment)and T5(48 hour long-term treatment),while the control group(CK)was not subjected to any treatment.A group of candidate transcription factors GATA family were identified through transcriptome analysis;(b HLH,MYB-related,GARP-G2-like,b ZIP,HB-HD-ZIP,C2H2,SET,m TERF,AP2/ERF-ERF,ARID,NAC,GARP-ARR-B,C2C2-GATA,FAR1,Trihelix,NF-YB,B3,and AUX/IAA).And may promote plant drought tolerance,especially long-term tolerance.DAP-seq identified a batch of differentially expressed target genes and verified them by RT-q PCR.TF HOVUSG2784400 has been proven to respond to long-term exposure to drought stress,regulating differential expression of genes,thereby improving the drought resistance of Qingke.The consistency between the Motif analysis of the promoter region peak obtained by DAP-seq analysis and the GATA transcription factor also points to the same results.More importantly,the related gene cluster IP＿HOR＿1、IP＿HOR＿2 and In HOR gene clusters can also prove that gene expression is indeed upregulated.