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.