Circadian clock PRR proteins stimulate anthocyanin synthesis in Arabidopsis thaliana seedlings

Abstract

The circadian clock is a conservative endogenous regulatory mechanism that stimulates and maintains the rhythmic expression of plant physiological characteristics. The PRR（PSEUDO-RESPONSE REGULATOR）protein family is a critical component of the circadian clock central oscillator and regulates a variety of life processes such as seed germination, hypocotyl elongation, and flowering. Anthocyanin is plant secondary metabolites, which plays an important role in plant reproduction, growth, development and stress responses. In this study, we took Arabidopsis thaliana as the research object and explored the function and mechanism of circadian clock PRR proteins in the control of anthocyanin biosynthesis. The results were as follows: (1) The accumulation of anthocyanin and the expression of some anthocyanin synthesis-related genes were significantly reduced in PRR genes single mutant and multiple mutant seedlings. (2) On the contrary, in the seedlings with overexpression of PRR5, the accumulation of anthocyanin and the expression of some anthocyanin synthesis-related genes were significantly increased. (3) The results of the protein-protein interaction experiment showed that PRR5 protein could interact with MYB75, MYB90, MYB113 and TT8 to form protein complexes. (4) Results of genetic analysis showed that PRR5 promoted anthocyanin synthesis in A. thaliana seedlings depended on the MYB family anthocyanin regulatory proteins. In conclusion, the circadian clock PRR protein may promote the synthesis and accumulation of anthocyanin in A. thaliana seedlings through the interaction of PRR5 protein with MYB75, TT8.

Keywords

• arabidopsis thaliana
• circadian clock
• prr protein
• anthocyanin
• mbw complex