Regulation of jasmonate biosynthesis by posttranslational modification of oxophytodienoate reductase (OPR) 3

通过氧化植物二烯酸还原酶 (OPR) 3 的翻译后修饰调节茉莉酸生物合成

• 批准号: 223067397
• 负责人: Professor Dr. Andreas Schaller
• 金额: --
• 依托单位: Fachgebiet Physiologie und Biochemie der Pflanzen (190c)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/223067397?language=en
• 关键词: Regulation; jasmonate; biosynthesis; posttranslational; modification

The induction of plant defense responses against insect herbivores is mediated by jasmonates which start to accumulate within minutes after insect attack or wounding. How the rapid formation of these phytohormones is initiated, remains an important open question in the defense signaling field. Rapid accumulation of jasmonates cannot be explained by changes in gene expression, but calls for post-translational mechanisms of regulation. According to our working hypothesis, post-translational regulation operates at the level of 12-oxophytodienoate reductase (OPR3), a central enzyme of jasmonate biosynthesis. We suggest that OPR3 activity depends on its oligomeric state which is controlled by reversible phosphorylation. The proposed research aims to substantiate this hypothesis by analyzing the oligomeric state of OPR3 in planta including its dynamic changes in response to environmental and developmental cues. OPR3 phosphorylation site(s) will be identified and wound-induced changes in phosphorylation quantified. We further aim to identify and characterize the protein kinase(s) responsible for OPR3 phosphorylation and determine it’s(their) role in defense signaling. This work will contribute substantially to a better understanding of jasmonate biosynthesis, plant defense signaling, structure activity relationships in OPR3, and the relevance of reversible protein phosphorylation in plants, particularly with respect to the regulation of defense responses.

植物对食草性昆虫的防御反应的诱导是由茉莉酸介导的，茉莉酸在昆虫攻击或伤害后几分钟内开始积累。这些激素的快速形成是如何启动的，在防御信号领域仍然是一个重要的悬而未决的问题。茉莉酸的快速积累不能用基因表达的变化来解释，但需要翻译后的调节机制。根据我们的工作假说，翻译后调控是在12-氧代植物二烯酸还原酶(OPR3)水平上进行的，OPR3是茉莉酸生物合成的中心酶。我们认为OPR3的活性依赖于其受可逆磷酸化控制的低聚状态。这项拟议的研究旨在通过分析植物中OPR3的寡聚状态，包括其随环境和发育线索的动态变化来证实这一假说。将确定OPR3磷酸化位点(S)，并量化创伤诱导的磷酸化变化。我们进一步的目标是鉴定和鉴定负责OPR3磷酸化的蛋白激酶(S)，并确定它在防御信号中的作用。这项工作将有助于更好地理解茉莉酸的生物合成、植物防御信号、OPR3中的结构活性关系以及植物中可逆蛋白质磷酸化的相关性，特别是在防御反应的调节方面。