Sulfur Dioxide Induces DNA Methylation Alteration of A Gene Encoding Nitrilase 2 Protein in Arabidopsis Plants
DNA methylation is involved in the regulation of many cellular processes. Environmental stimuli induce DNA methylation alterations which may have important consequences for plant adaptations. In this study, SO2-induced DNA methylation alteration of a gene encoding nitrilase 2 protein(NIT2) in Arabidopsis was investigated by using bisulfite sequencing and methylation sensitive restriction enzyme PCR. Quantitative analysis of DNA methylation in NIT2 promoter region showed that cytosine residues were hypomethylated in both CG and CHH (where H is C, A or T ) contexts after plant exposed to 30 mg · m-3 SO2 for 3 d, and the methylation levels of the promoter decreased from 37% to 32%. However, cytosine methylation change in the sequence CCGG in the upstream part of NIT2 coding region could not be detected in SO2-exposed plants. RT-PCR analysis indicated that NIT2 transcript level increased markedly in plants exposed to 30 mg · m-3 SO2 for 3 d. The present results showed that DNA hypomethylation of NIT2 promoter region was associated with high NIT2 transcript level in S02-exposed plants. Our results were consistent with the previous report that NIT2 was overexpressed in an Arabidopsis mutant deficient in DNA methyltransferase, indicating that NIT2 expression was directly regulated by promoter DNA methylation. These data suggest that SO2-induced epigenetic change may be closely related to the gene activation in plant response to SO2 stress. Our report may help to reveal a possible role of this epigenetic mechanism in plants adaptation to environmental stress.
国家科技期刊平台
NSTL
万方数据
维普
