Apple bZIP transcription factor MdbZIP44 regulates abscisic acid‐promoted anthocyanin accumulation

作者：Jian‐Ping An, Ji‐Fang Yao, Ruirui Xu, Chun‐Xiang You, Xiao‐Fei Wang, Yu‐Jin Hao · 发表于：Plant Cell & Environment · 年份：2018 · DOI：10.1111/pce.13393 · 被引用次数：315 · 研究领域：Plant Gene Expression Analysis、Plant Molecular Biology Research、Plant biochemistry and biosynthesis

Phytohormone abscisic acid (ABA) induces anthocyanin biosynthesis; however, the underlying molecular mechanism is less known. In this study, we found that the apple MYB transcription factor MdMYB1 activated anthocyanin biosynthesis in response to ABA. Using a yeast screening technique, we isolated MdbZIP44, an ABA-induced bZIP transcription factor in apple, as a co-partner with MdMYB1. MdbZIP44 promoted anthocyanin accumulation in response to ABA by enhancing the binding of MdMYB1 to the promoters of downstream target genes. Furthermore, we identified MdBT2, a BTB protein, as an MdbZIP44-interacting protein. A series of molecular, biochemical, and genetic analysis suggested that MdBT2 degraded MdbZIP44 protein through the Ubiquitin-26S proteasome system, thus inhibiting MdbZIP44-modulated anthocyanin biosynthesis. Taken together, we reveal a novel working mechanism of MdbZIP44-mediated anthocyanin biosynthesis in response to ABA.