Functional Study Of Rice Histone Acetyltransferase Gene OsGCN5 In Response To Salt Stress

Rice is the staple food of more than 60%of the population in my country,and the production of rice is directly related to the food security of the country.Epigenetic regulation plays a key role in the growth and development process and stress response of crops.Histone acetylation is one of the important ways of epigenetic regulation,which is jointly catalyzed by histone acetyltransferase and deacetylase.In this study,the histone acetyltransferase gene OsGCN5 was selected as the research object,and the mechanism of its participation in rice response to salt stress was analyzed through molecular genetics and bioinformatics analysis methods.The following main research results were obtained:1.Phylogenetic tree analysis and homologous sequence analysis showed that OsGCN5 belonged to the GANT family in HAT,and had the highest homology with GCN5 in maize;promoter sequence analysis showed that the promoter of OsGCN5 contained a variety of cisacting elements related to stress response;The results of tissue-specific expression analysis showed that the expression of OsGCN5 was the highest in leaf sheaths and leaves,and OsGCN5 was localized in the nucleus and belonged to nuclear proteins.2.Through genetic transformation,we constructed OsGCN5-related knockout materials(all non-frameshift weak mutation types KO-1,KO-2),overexpression materials(OE-1,OE2)and interference materials(RNAi-1.RNAi-2).The main agronomic traits of different transgenic materials were investigated,and it was found that the plant height,panicle length and flag leaf length of the knockout and interference materials were significantly reduced,and the overexpression materials were increased,but the difference was not significant,indicating that the OsGCN5 gene may play a role in the growth and development of rice plants.There is influence.3.OsGCN5 can catalyze the acetylation activity on the 18/27/36 lysine residues of histone H3 in vitro,and can catalyze the 18/27 of histone H3 and the 5/8 of histone H4 in vivo.The acetylation activity on lysine residues indicates that OsGCN5 can specifically catalyze acetylation on histone-related sites.4.RT-qPCR analysis was performed on Nipponbare under different concentrations of salt stress,and it was found that the expression level of OsGCN5 showed an increasing trend with the increase of salt concentration,indicating that the expression of OsGCN5 could be induced by salt stress.Then,the different genetically transformed materials of OsGCN5 were treated with salt stress to observe the phenotype and measure the physiological indicators.Compared with the wild-type Nipponbare,the overexpression materials had better growth condition and higher survival rate,and all the physiological indicators showed resistance to salt stress.In contrast,the knockout and interference materials exhibited sensitivity to salt stress.5.Transcriptome data analysis of OsGCN5 overexpression materials found that GOenriched differentially expressed genes were mainly enriched in biological processes such as stimulus response,stress response,and defense response,as well as in RNA modification processes,and 8 genes were screened that were related to salt stress.Response-related genes,among them,the Na+ transporter gene OsHKT2;1 involved in the regulation of salt stress is negatively correlated with OsGCN5.Through RT-qPCR verification,it was confirmed that the expression of OsHKT2;1 was inhibited by OsGCN5 under salt stress,and OsGCN5 was regulated by RNA Modifications involved in the regulation of rice salt stress response.Through this study,it was determined that OsGCN5 is indeed involved in the regulation of rice salt stress,and the specific mechanism needs further research and verification.The relevant research has laid a theoretical foundation for rice salt-tolerant breeding and provided a new direction.