RNA-Seq-Based Profiling of Mutant Reveals Transcriptional Regulation of Anthocyanin Biosynthesis in Rice ( L.).

Purple-colored leaves in plants attain much interest for their important biological functions and could be a potential source of phenotypic marker in selecting individuals in breeding. The transcriptional profiling helps to precisely identify mechanisms of leaf pigmentation in crop plants. In this study, two genetically unlike rice genotypes, the mutant () and wild (WT) were selected for RNA-sequencing and identifying the differentially expressed genes (DEGs) that are regulating purple leaf color. In total, 609 DEGs were identified, of which 513 and 96 genes were up- and down-regulated, respectively. The identified DEGs are categorized into metabolic process, carboxylic acid biosynthesis, phenylpropanoids, and phenylpropanoid biosynthesis process enrichment by GO analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) confirmed their association with phenylpropanoid synthesis, flavonoid synthesis, and phenylalanine metabolism. To explore molecular mechanism of purple leaf color, a set of anthocyanin biosynthetic and regulatory gene expression patterns were checked by qPCR. We found that (, , , and ), (), (), and () are associated with anthocyanin biosynthesis, and they were up-regulated in leaves. Two members of regulatory genes (; and ), two genes ( and ), and two WD40 genes ( and ) also showed up-regulation in mutant. These genes might have significant and vital roles in leaf coloration and could provide reference materials for further experimentation to confirm the molecular mechanisms of anthocyanin biosynthesis in rice.