Preliminary Study On Response Of TaHDA19 Gene To High Temperature Stress In Wheat

In the research of plant genetics and breeding,traditional breeding and classical genetics are the main research methods,while epigenetics is not much,and the research in wheat is very little.With the deepening of research in recent years,epigenetics has become more and more popular in plant research,such as methylation and acetylation,and other protein modifications.Many studies have been reported,pointing out that they play an important role in plant growth,development and stress.As an important food crop,the yield and quality of wheat are related to the food problem of millions of people.Therefore,it is the goal of every researcher to cultivate high-yield,high-resistance and high-quality wheat.Wheat is an allohexaploid with a huge genome,which hinders wheat research and lags behind other crops.Histone deacetylase?HDACs?plays an important role in plant growth and stress resistance in other plant studies.In this study,we screened a wheat HDACs gene and named it TaHDA19.Using wheat Kenong 199 as experimental material,we studied the role of TaHDA19 gene in abioticstress of wheat through related experiments.The main results are as follows:1.According to Ensemble plant,NCBI and other databases,gene and protein sequences were obtained by bioinformatics analysis.The total length of gene was 1560 bp and 519 amino acids.Seven homologous protein sequences of Arabidopsis thaliana,barley and Aegilops crude were screened.Multiple sequence alignment showed that the protein sequences all contained typical domains of HDACs family.Evolution analysis showed that the gene had high homology with Arabidopsis AtHDA19 and was a member of RPD3/HDA1 subfamily,so it was named TaHDA19.In addition,the cis-element analysis of the promoter region showed that the promoter region of TaHDA19 contained multiple response elements,such as light response elements?I-box and G-box?,abscisic acid response elements?ABRE?,low temperature response elements?LTR?.2.To study the expression of TaHDA19 in different tissues and under different abiotic stresses of wheat KN199.The results showed that the expression level of TaHDA19 gene was different in different tissues and under different abiotic stresses.TaHDA19 was expressed in roots,stems,leaves and young panicles,but its expression in leaves was relatively high.Abscisic acid?ABA?,salt and drought stress,with the extension of time,the expression of abscisic acid?ABA?was different.Compared with the control,the expression of ABA increased first,then decreased and then increased.After 1 hour of heat stress at 35?and 42?,the expression level of wheat was up-regulated in 12 stages.These results suggest that TaHDA19 gene may play a role in abiotic stress response in wheat.3.Designing specific primers,cloning TaHDA19 gene sequence by PCR technology,and using the pGEM-Ubi-GFP-nos plasmid preserved in the laboratory,we constructed the overexpression vector by one-step cloning kit,and transferred it to KN199 wheat immature embryo callus by gene gun mediation.Twenty-five transgenic wheat strains were obtained after tissue culture.Seven T₀-positive transgenic wheat seeds were finally harvested and planted in greenhouse,and 58 positive T₁-generation transgenic wheat were obtained.4.The relative chlorophyll content of T₁ plants decreased in both Transgenic wheat and KN199,but the decrease of Transgenic wheat was small.The results of relative conductivity and malondialdehyde content analysis showed that the content of Transgenic wheat and KN199 increased,but the increase of Transgenic wheat was smaller than that of control KN199.Proline content also increased in Transgenic wheat and KN199,but Transgenic wheat increased more than contrast KN199.These results indicated that the heat tolerance of transgenic plants was stronger than that of wild-type plants under 42?high temperature stress.