茉莉酸甲酯信号途径的调控模式研究新进展

Developmental Cell：茉莉酸甲酯信号途径的调控模式研究新进展赤霉素（Gibberellins，GAs）调控茉莉酸甲酯（JA）的信号转导途径，而JA信号途径在植物发育和胁迫诱导中起着非常重要的作用。JA作为植物发育中重要的信号途径，一直是研究热点。然而，植物各种信号途径之间的调控网络复杂，大部分植物激素之间的相互作用仍然不清楚。

DELLAs通过与JAZs的竞争性结合调控JA信号途径的“抑制释放模型”图

中科院华南植物园植物种质创新与基因发掘领域夏快飞博士与新加坡国立大学植物发育学实验室的侯兴亮博士后，一起致力于JA调控途径中JAZ1(茉莉酸受体ZIM结构域蛋白)、DELLA(DELLA家族蛋白)、MYC2(MYC转录因子)及GA（赤霉素）之间的相互作用研究，发现DELLAs在JA信号途径中起着重要作用，同时也揭示JA信号途径可能通过DELLAs与别的信号途径起着重要的联系作用。没有JA，JAZs能稳定的与MYC2结合，因此抑制了MYC2作为转录激活子的活性。而加入JA，JA则与JAZs结合，释放出MYC2，从而激活了JA途径中的反应基因的表达。在JA信号途径中没有GA，DELLAs能稳定的与JAZs结合，释放出MYC2激活JA途径。加入GA，则GA促进了DELLAs的降解，导致JAZ-MYC2复合子的形成，从而抑制了JA信号途径。

该研究结果已发表在国际重要刊物Developmental Cell（DOI 10.1016/j.devcel. 2010.10.024）上。（生物谷

生物谷推荐原文出处：

Developmental Cell  DOI 10.1016/j.devcel. 2010.10.024

DELLAs Modulate Jasmonate Signaling via Competitive Binding to JAZs

Authors

Xingliang Hou, Li Yen Candy Lee, Kuaifei Xia, Yuanyuan Yan, Hao Yu

Highlights

Gibberellins (GAs) inhibit DELLA-mediated upregulation of jasmonate (JA) target genes

DELLAs compete the JA signaling repressor JAZ1 away from the JA effector MYC2

DELLA/JAZ binding derepresses MYC2‘s ability to regulate JA-responsive genes

DELLAs promote cellular competence to respond to JA

Summary

Gibberellins (GAs) modulate jasmonate (JA) signaling, which is essential for stress response and development in plants. However, the molecular details of such phytohormone interaction remain largely unknown. Here, we show that the JA ZIM-domain 1 (JAZ1) protein, a key repressor of JA signaling, interacts in vivo with DELLA proteins, repressors of the GA pathway. DELLAs prevent inhibitory JAZ1 interaction with a key transcriptional activator of JA responses, MYC2, and, thus, enhance the ability of MYC2 to regulate its target genes. Conversely, GA triggers degradation of DELLAs, which allows JAZ1 to bind MYC2 and suppress MYC2-dependent JA-signaling outputs. Therefore, our results reveal one means by which GAs suppress cellular competence to respond to JA. Because DELLAs serve as central regulators that mediate the crosstalk of various phytohormones, our model also suggests a candidate mechanism by which JA signaling may be fine-tuned by other signaling pathways through DELLAs.