| Histone H3K36lysine methylation plays an essential role in epigenetic regulation of gene expression in eukaryotes.Enzymes responsible for H3K36methylation have been reported in Arabidopsis but absent in rice. Here we report a rice H3K36-specific methyltransferase SDG725which down-regulation mutants display multiple defects, including dwarfism, shortened internodes, late flowering, erect leaves and small seeds. The dwarf and erect phenotypes have been usually described in brassinosteroid (BR)-knockdown mutants. We examine the expression level of rice flowering genes and brassinosteroid-related genes and found that these related genes are all down-regulated in sdg725background. To further detect the function of SDG725in vivo, we did Chromatin immuno-precipitation (ChIP) in WT and sdg725, respectively. The H3K36m2/m3levels were down-regulated in some brassinosteroid pathway and the flowering related genes. Moreover, the SDG725protein was able to directly bind at these target genes.Taken together, our data indicate that the SDG725-mediated H3K36methylation modulates BR-related and rice flowering related genes expression, playing an important role in rice plant growth and development. |
