Tyrosine Induces Anthocyanin Biosynthesis in Arabidopsis thaliana

Anthocyanins are widely found in plants and are responsible for the purple coloration of plants. Anthocyanin biosynthesis is induced by environmental stresses, plant hormones, sugar, and so on. Tyrosine (Tyr) is the precursor of melanin that exits in both animals and plants. However, until now it has been unknown whether Tyr induces anthocyanin biosynthesis. In this study, the seedlings of Arabidopsis thaliana were treated with exogenous Tyr and then the anthocyanin accumulation was determined. The results showed that Tyr induced anthocyanin accumulation in Arabidopsis thaliana in a dose-dependent manner. Furthermore, the expression of the late anthocyanin biosynthetic genes including DFR, LDOX, and UF3GT, and the transcription factor genes PAP1, PAP2, and EGL3 was induced by Tyr. Taken together, these results demonstrated that Tyr is able to induce anthocyanin accumulation and suggested that Tyr up-regulates transcription factors PAP1, PAP2, and EGL3, which mediates the expression of the late anthocyanin biosynthetic genes and then induces anthocyanin biosynthesis.