Arabidopsis SnRK2.9 interacts with FAH1 to regulate sucrose-induced anthocyanin.

Sucrose has been found to possess regulatory characteristics in the biosynthesis of anthocyanin. The interplay between SnRK2s and the regulation of both anthocyanin production and sugar accumulation is significantly influential. However, a comprehensive understanding of the precise mechanism linking SnRK2s to anthocyanin remains limited. In the study, we have made a significant discovery regarding the role of the gene FAH1 (ferulate 5-hydroxylase)-mediated regulation of sucrose-induced anthocyanin biosynthesis in Arabidopsis. By employing a screening process using an Arabidopsis cDNA library with FAH1 as bait, it successfully identified protein kinase SnRK2.9, which is involved in the regulatory pathway. Subsequent pull-down and Co-IP assays provided further confirmation of the physical interaction between SnRK2.9 and FAH1. Moreover, our findings suggest that under high levels of sucrose exposure, SnRK2.9 negatively modulates both the stability and enzymatic activity of FAH1 protein. The research provides valuable insights into the regulatory mechanisms employed by plants to modulate the anthocyanin response triggered by sucrose.