Isolation and expression analysis of the HvnAnt2 gene in qingke barley (Hordeum vulgare L. var. nudum Hook. f.) varieties with different grain colours

To investigate the role of the HvnAnt2 gene in the formation of different qingke barley grain colours, HvnAnt2 was isolated from the leaves of the White 91-97-3 (white), Blue qingke (blue), Kunlun 17 (black), and Purple qingke (purple). The HvnAnt2 gene encodes a hydrophilic unstable protein consisting of 561 amino acids, without a transmembrane structure and without a signal peptide, with one bHLH-MYC_N and one HLH domain at amino acids 22-204 and 387-436, respectively. The HvnAnt2 of qingke barley was most closely related to Hordeum vulgare and most distantly related to Triticum monococcum; it was mainly related to light responsiveness and methyl jasmonate responsiveness. The Ant2 gene was highly expressed in Kunlun 17 and Purple qingke barley grains during the later stage of development. The protein interaction prediction showed that flavonoid 3'-monooxygenase, anthocyanin biosynthesis gene regulators, and key enzymes in folate metabolism interacted with the Ant2 protein. This study provides a reference for further analysis of the Ant2 gene in the anthocyanin synthesis pathways of qingke barley with different grain colours.