Comparative Transcriptome Analysis Revealing the Effect of Light on Anthocyanin Biosynthesis in Purple Grains of Wheat

To study the mechanism of anthocyanin-biosynthesis regulation, we examined light-regulated gene expression involved in anthocyanin biosynthesis in purple grains of wheat. Ten kinds of anthocyanins were identified from a purple-grained wheat cultivar by HPLC-ESI-MS/MS analysis. Libraries constructed from the total RNA of purple grains under light (L) or dark (D) conditions for 15 or 20 days were sequenced. In total, 1874 differentially expressed genes (DEGs) were identified in L20 vs L15, 1432 DEGs were identified in D20 vs D15, 862 DEGs were identified in D15 vs L15, and 1786 DEGs were identified in D20 vs L20. DEG functional enrichments suggested that light-signal transduction is critical to anthocyanin biosynthesis. The 911 DEGs referred to as light-regulated DEGs (LDEGs) involved a number of genes in anthocyanin biosynthesis, transcription regulation, sugar- and calcium-signaling pathways, and hormone metabolism. These findings laid the foundation for future studies on the regulatory mechanisms of anthocyanin biosynthesis in purple grains of wheat.