Apple bZIP transcription factor MdbZIP44 regulates abscisic acid-promoted anthocyanin accumulation
Apple bZIP transcription factor MdbZIP44 regulates abscisic acid-promoted anthocyanin accumulation
复制标题
苹果bZIP转录因子MdbZIP44调节脱落酸促进花青素积累
DOI：
10.1111/pce.13393
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发表时间：
2018-11-01
影响因子：
7.3
通讯作者：
Hao, Yu-Jin
中科院分区：
文献类型：
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作者：
An, Jian-Ping;Yao, Ji-Fang;Hao, Yu-Jin
植物激素脱落酸(ABA)诱导花青素的生物合成，但其潜在的分子机制还不是很清楚。在本研究中，我们发现苹果MYB转录因子MdMYB1在ABA刺激下激活了花青素的生物合成。通过酵母菌筛选技术，我们分离到了ABA诱导的苹果bZIP转录因子MdbZIP44，作为MdMYB1的合作伙伴。MdbZIP44通过增强MdMYB1与下游靶基因启动子的结合，促进花青素的积累。此外，我们还鉴定了BTB蛋白MdBT2是一种与MdbZIP44相互作用的蛋白。一系列的分子、生化和遗传分析表明，MdBT2通过泛素-26S蛋白酶体系统降解MdbZIP44蛋白，从而抑制MdbZIP44调控的花青素的生物合成。综上所述，我们揭示了MdbZIP44介导的花青素生物合成响应ABA的一种新的工作机制。
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.