The Study Of Histone H3K36 Methytransferase SDG725 In Regulation Of Rice Flowering Time And Identification Of SDG725 Binding Proteins

Histone methylation exists widely in plants and animals, the lysine methylation on histone H3 plays important biological roles, including transcriptional activation related H3K4/H3K36 methylationan transcriptional repression associated with H3K9/H3K27 methylation.SDG725 is a rice H3K36-specific methyltransferase, and the down-regulation of SDG725mutants (725Ri) display multiple defects, including dwarfism, shortened internodes, erect leaves, small seeds and late flowering. We examined the expression level of key flowering genes in 725Ri background and found that Hd3aand RFT1 are down-regulated in 725Ri background. Chromatin Immune-Precipitation (ChIP) experiment showed the H3K36m2/3 levels on some chromatin regions of Hd3a and RFT1 were also down-regulated in 725Ri mutant.A normalized full-length cDNA library was constructed into yeast expression vector. The library reaches the capacity of 2.0×106cfu, redundancy rate of 1% and recombination rate of 95%. Using this yeast two hybrid library, we screened the binding proteins of SDG725, we find several potential SDG725 binding proteins, including a transcription factor SDG725BP-1, which will be helpful for further study of SDG725 function.