Roles of DNA methyltransferases in Arabidopsis development

DNA methylation plays a vital role during development in gene expression and chromatin organization. DNA methyl transferases catalyze the transfer of a methyl group to bases within the DNA helix. Plants differ from animals in having methylation at the sites of CHG and CHH. In plant, there are at least four classes of cytosine methyltransferase: MET1, CMT3, DRM and DNMT2. They show distinct expression patterns and levels in tissues and developmental stages and differential activity on cytosines in different sequence contexts. Mutations that cause severe loss of DNA methylation often leads to abnormal development. In the present review, we summarized recent findings of the three major DNA methyltransferases mutants playing vital role in development of Arabidopsis thaliana.