Coexpression of Structural and Regulatory Genes of the Flavonoid Pathway Reveals the Characteristics of Anthocyanin Biosynthesis in Eggplant Organs (Solanum melongena L.)

Eggplant (Solanum melongena L.) is an economically important vegetable crop whose purple-colored fruits are enriched with anthocyanidins. In this work in the eggplant genome, homologues of the main known structural (CHS1, CHS2, CHI, F3H, F3´5´H, DFR, ANS, and UFGT) and regulatory (TT8, GL3, bHLH137, bHLH143, MYB1, MYB2, and MYB75) anthocyanin biosynthesis genes, as well as anthocyanidin transporter gene (GSTF12), were identified. The expression of these genes was characterized in comparison with the content of the total anthocyanins and the color of the leaf, flower petals, and fruit peel. It was shown that the gene expression pattern corresponds to the color and the presence of anthocyanins in the tissue, and also indicates the presence of organ-specific characteristics of the regulation of transcription of genes encoding transcription factors of the MBW complex. The results of correlation analysis confirm the involvement of SmbHLH137, SmTT8, SmMYB2, and SmMYB75 genes in the regulation of the expression of structural genes in flower petals and SmGL3, SmTT8, and SmMYB1 in fruit peel.