A TCP Transcription Factor in , , Positively Regulates Anthocyanins Biosynthesis.

Anthocyanins belong to a group of flavonoids, which are the most important flower pigments. Clarifying the potential anthocyanins biosynthesis molecular mechanisms could facilitate artificial manipulation of flower pigmentation in plants. In this paper, we screened a differentially expressed gene, , from the transcriptome data of petals at different development stages and explored its role in anthocyanins biosynthesis. The transcriptome data and qRT-PCR analysis showed that the expression level of gradually decreased from the flower color fades. Tissue specific expression analysis showed was expressed in the petal, leaf, and fruit of , and was highly expressed in the scarlet petal. Overexpression of promoted anthocyanins accumulation and increased pigments in infected parts of 'Snowdrift' and 'Fuji' fruit peels. In contrast, when endogenous was silenced, the anthocyanins accumulation was inhibited and pigments decreased in the infected peels. The qRT-PCR analysis revealed that overexpression or silence of caused expression changes of a series of structural genes included in anthocyanins biosynthesis pathway. The yeast two-hybrid assays indicated that MhTCP4 did not interact with MhMYB10. Furthermore, the yeast one-hybrid assays indicated that MhTCP4 did not directly bind to the promoter of , but that of the anthocyanins biosynthesis genes, and . Dual luciferase assays further confirmed that MhTCP4 can strongly activate the promoters of and in tobacco. Overall, the results suggest that positively regulates anthocyanins biosynthesis by directly activated and in flowers.