[Effect of napthalene on the DNA methylation patterns and level in rice (Oryza sativa L.)]

In this study,two elite rice inbred lines, Nipponbare and Mastumae were selected and irrigated with naphthalene solution with different concentrations. Epigenetic instabilities in the blade of the plants in tillering and heading stage were assessed by MSAP marks. The results showed that naphthalene exposure induced epigenetic variations in all the samples based on different levels and patterns of DNA methylation. The changes of the percentage of 5-methylcytosine have no regulation. In total 1051 sites tested,the variation of 16.56 percentage of Nipponbare has significant difference compared with the variation of 12.08 percentage of Mastumae,which showed that the capability to resist naphthalene pollution was related to genotype and Mastumae was stronger than Nipponbare in the capability to resist naphthalene pollution. The variations of DNA methylation in different genotypes and different growth periods have significant differences. In general, the frequencies of demethylation (0.48%-10.41%) were higher than hypermethylation (0.10%-1.92%). We concluded that DNA demethylation might be one part of in plants mechanism to resist naphthalene pollution in plants.