DELLA Proteins Promote Anthocyanin Biosynthesis via Sequestering MYBL2 and JAZ Suppressors of the MYB/bHLH/WD40 Complex in Arabidopsis thaliana
DELLA Proteins Promote Anthocyanin Biosynthesis via Sequestering MYBL2 and JAZ Suppressors of the MYB/bHLH/WD40 Complex in Arabidopsis thaliana
复制标题
DELLA 蛋白通过隔离拟南芥中 MYB/bHLH/WD40 复合物的 MYBL2 和 JAZ 抑制子促进花青素生物合成
DOI：
10.1016/j.molp.2016.01.014
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发表时间：
2016
期刊：
影响因子：
27.5
通讯作者：
Huang Jirong
中科院分区：
文献类型：
--
作者：
Xie Ye;Tan Huijuan;Ma Zhaoxue;Huang Jirong
花青素积累被认为是植物遭受环境胁迫的一种可见生物标志物。然而，胁迫诱导花色素苷生物合成的分子机制仍不清楚。花色素苷特异性基因的表达受保守的MBW复合体调控，该复合体由MYB、bHLH和WD 40亚基组成。MBW活性受到MYBL 2和JAZ家族蛋白的抑制，它们分别与bHLH和MYB/bHLH竞争性结合。在这里，我们发现MYBL 2和JAZ介导赤霉酸抑制的拟南芥花色素苷生物合成。竞争性下拉和双荧光素酶分析表明，DELLA蛋白直接螯合MYBL 2和JAZ阻遏物，导致bHLH/MYB亚基的释放，随后形成活性MBW复合物，然后激活花青素生物合成途径。JAZ-DELLA-MYBL 2模块在非生物胁迫诱导的花青素苷生物合成中也起重要作用。此外，我们发现，DELLA蛋白RGA积累植物暴露于非生物胁迫。总而言之，我们的数据表明，DELLA促进的花青素生物合成至少部分由MYBL 2和JAZ调节蛋白介导，为通过代谢途径调节植物生长和防御的协调调节提供了新的见解。
Anthocyanin accumulation is recognized as a visible biomarker of plants that have suffered from environmental stresses. However, the molecular mechanisms underlying stress-induced anthocyanin biosynthesis remain unclear. Expression of anthocyanin-specific genes is regulated by the conserved MBW complex, which is composed of the MYB, bHLH, and WD40 subunits in higher plants. MBW activity is repressed by MYBL2 and the JAZ family proteins, which bind competitively to bHLH and MYB/bHLH, respectively. Here, we found that MYBL2 and JAZs mediate gibberellic acid-inhibited anthocyanin biosynthesis inArabidopsis. Competitive pull-down and dual-luciferase assays showed that DELLA proteins directly sequester MYBL2 and JAZ repressors, leading to the release of bHLH/MYB subunits and subsequently to the formation of active MBW complex, which then activates the anthocyanin biosynthetic pathway. The JAZ-DELLA-MYBL2 module also plays an important role in abiotic stress-induced anthocyanin biosynthesis. Furthermore, we found that the DELLA protein RGA accumulates upon plant exposure to abiotic stresses. Altogether, our data reveal that DELLA-promoted anthocyanin biosynthesis is mediated at least in part by MYBL2 and JAZ regulatory proteins, providing new insights into the coordinated regulation of plant growth and defense through metabolic pathway regulation.