GATA and Phytochrome Interacting Factor Transcription Factors Regulate Light-Induced Vindoline Biosynthesis in .

is the exclusive source of an array of terpenoid indole alkaloids including the anticancer drugs vincristine and vinblastine, derived from the coupling of catharanthine and vindoline. Leaf-synthesized vindoline is regulated by light. A seven-step enzymatic process is involved in the sequential conversion of tabersonine to vindoline; however, the regulatory mechanism controlling the expression of genes encoding these enzymes has not been elucidated. Here, we identified CrGATA1, an Leu-Leu-Met domain GATA transcription factor that regulates light-induced vindoline biosynthesis in seedlings. Expression of and the vindoline pathway genes , , , , and was significantly induced by light. In addition, CrGATA1 activated the promoters of five light-responsive vindoline pathway genes in plant cells. Two GATC motifs in the promoter were critical for CrGATA1-mediated transactivation. Transient overexpression of in seedlings resulted in up-regulation of vindoline pathway genes and increased vindoline accumulation. Conversely, virus-induced gene silencing of in young leaves significantly repressed key vindoline pathway genes and reduced vindoline accumulation. Furthermore, we showed that a Phytochrome Interacting Factor, CrPIF1, is a repressor of and vindoline biosynthesis. Transient overexpression or virus-induced gene silencing of in seedlings altered and vindoline pathway gene expression in the dark. CrPIF1 repressed and promoter activity by binding to G/E-box/PBE elements. Our findings reveal a regulatory module involving Phytochrome Interacting Factor -GATA that governs light-mediated biosynthesis of specialized metabolites.