Genetic regulation of anthocyanin biosynthesis in barley: insights into purple pigmentation in the Zipi genotype

Colored crops are increasingly used in agricultural landscapes to attract tourists to rural areas. In plants, the pigments responsible for vibrant colors are primarily anthocyanins. However, the molecular mechanisms underlying anthocyanin biosynthesis remain elusive. In this study, we investigated the molecular mechanisms behind the purple pigmentation in the stalks and husks of barley genotype Zipi. Using UPLC-Q-TOF-MS analysis, we identified cyanidin 3-O-glucoside as the primary anthocyanin, with significant accumulation in Zipi compared to yellow variety Golden Promise. Transcriptomic analysis revealed that structural and transport genes involved in anthocyanin biosynthesis, such as HvCHS, HvCHI, HvANS, and HvGST, as well as their upstream regulators HvANT1 and HvANT2, exhibited higher expression in Zipi. A weighted gene co-expression network analysis (WGCNA) identified HvMYB112 as a key upstream regulator of anthocyanin biosynthesis, activating the transcription of HvANT1, which was proved using dual-luciferase reporter assay. These findings provide crucial insights into the genetic regulation of anthocyanin accumulation in barley, offering a potential pathway for breeding ornamental barley varieties with enhanced pigmentation.