Global Characterization\nof DNA Methylation during\nRice Leaf Angle Development

During plant development and growth, genomic DNA accumulates\nchemical\nmarkers that determine the levels of gene expression. DNA methylation\nis an important epigenetic marker involved in plant developmental\nevents. However, the characterization of the role of DNA methylation\nin rice leaf angle development has lagged behind. Herein, we performed\nbisulfite sequencing to characterize DNA methylation sites and performed\ntranscriptome and small RNA sequencing during leaf angle development.\nThe results revealed a global reduction in CG methylation during leaf\nangle establishment. A reduction in gene body CG methylation appears\nto play a vital role in leaf angle development. The hypomethylated\nand weakly expressed genes were functionally enriched in the brassinosteroid\nand auxin signaling pathways. Additionally, the main DNA methyltransferases\nwere inactive. The addition of exogenous DNA methylation inhibitor\n5-azacytidine increased the leaf angle, which confirmed that DNA methylation\nis crucial for leaf angle development. This study revealed a gradual\ndecrease in 24-nucleotide siRNA levels during leaf angle development,\nparticularly in relation to the enrichment of 24-nucleotide siRNAs\nat different hypomethylated regions that induce leaf angle inclination.\nOur results indicate crucial roles for DNA methylation in the rice\nleaf angle developmental stages.