Study On The Effect Of DNA Cytosine Methylation Variations Induced By Drought Stess In Millet

Drought is the most common environmental stress in the world,and one of the most serious stresses on crop damage.In recent years,people pay more and more attention to the problem of crop production caused by drought.Drought resistance research has become a global research field.The responses of plants to drought are reflected in various growth and development stages.Many studies have found that epigenetic modification can affect plant growth and development.In particular,DNA methylation is an important component of epigenetic modification,which plays an important role in the regulation of gene expression and the process of genome defense.Studies have found that stress could lead to plant DNA methylation variation.In order to research epigenetic mechanism in drought stress on plants,In this study,the drought-resistant millet cultivar YuGu 1 was used as experimental material.We used 20% PEG to simulate drought stress conditions.After treatment with millet for 2h,6h,12 h,24h,3d and 5d,we randomly mixed the leaf DNA at each point.MSAP were used to detect the levels and patterns of DNA methylation,and then to analyze the variation caused by drought stress in millet.A total of 1520 clear loci were detected,the methylation rate ranged from 10.92% to 11.05%.The hemi-methylation loci were 30-57,reprinted 1.97%-3.75% of the total loci and110-138 of fully methylation loci,represented 7.24%-9.08% of the total loci.It was demonstrated that millet methylome has more fully methylated in the millet.Analysis of methylation sites revealed that the mCG level was 3.9% and 3.7% higher than mCNG and mCG / CNG levels,respectively.It indicated that methylation occured mostly at the CG site.The methylation variation is 0.52%-2.11%.The hypermethylation were 0.13%-0.54%,and the demethylation were 0.13%-1.78%.According to the analysis of the details of methylation variation,methylation variation occurred mainly in the CNG locus,the hypermethylation at the CNG site was 0.07%-0.20% of the total locus,and the demethylation was 0.13 %-1.64% of the total locus.Nine MSAP polymorphic gel bands were recollected and sequenced.Blast N and Blast X analysis showed that the methylation variation sequence caused by droughtstress was homologous to the peroxidase gene in the millet.This suggests that methylation mutations interact with plant-related protein genes in response to drought stress in response to stress.