Study On Genomic DNA Methylation Variations Induced By Ozone Stress In Foxtail Millet And Its Inheritance

Environmental stresses can induce plant epigenetic variations.As one of the most important epigenetic modifications,DNA methylation is common and plays a significant role in maintaining genome stable,regulating gene expression and improving the adaptive ability to stresses.As a kind of environmental stress,ozone(O3)has a harmful effect on plants growth.Plants often regulate their gene expression patterns to resist the stress.In order to study the epigenetic mechanism responding to ozone stress and explore the possible related genes,we used foxtail millet as the material to evaluate the leaf damage extent and the DNA methylation variations in S0 and S1 generations under 200nmol·mol-1ozone stress by using open top chambers(OTCs).By MSAP,1737 clear sites were obtained and a total of 1613-1683 bands were amplified,of which 188-236 methylated-related bands,accounted for 10.82%-13.59%of the total sites,demethylated bands for 0.52%-5.58% of the total sites,methylated bands for 0.35%-2.76% of the total sites.It was demonstrated that the variations of DNA methylation was induced by ozone stress and that the CNG loci was the main contributor of the DNA methylation alterations.By analyzing S0 and S1 generations,it was demonstrated that the inheritance of DNA methylation variations induced by O3 was various in the next generations.The analysis of variation bands indicated that the DNA methylation variations induced by O3 exist in different chromosomes of foxtail millet,and their protein sequence were homology with different functional genes,which implicates that changes of DNA methylation may be an important way for plants in responses to ozone stress.Our study provides a theoretical basis and reference to realize the mechanisms of foxtail millet to adapt ozone.