Regulation of the early steps of wound-activated jasmonate biosynthesis

为了满足全球粮食生产日益增长的需求，必须尽量减少虫害造成的作物损失。植物的许多抗虫反应都是由茉莉酸（JA）激素信号介导的。该项目的更广泛的目标是了解植物的内置防御机制介导的JA作为一个重要的一步，发展可持续的害虫缓解措施。更具体地说，这个项目将阐明JA生物合成的第一步，以及它是如何与植物细胞对害虫攻击的感知相联系的。现有的证据指向参与酶称为脂肪酶水解膜脂质作为主要的调节点。揭示脂肪酶的生化调控在食品、化妆品、洗涤剂和制药工业中具有潜在的应用。此外，膜离子通道类似于参与动物神经传递的那些，参与植物中害虫激活的防御反应。了解这些元素是如何组织和参与跨王国执行类似功能的是迷人的，并将导致对细胞信号传导的更基本的理解。该项目将以多种方式促进STEM教育和公众科学素养。首先，通过PI的核心和机构计划，将直接和间接地促进本科生参与研究。第二，将通过Sci-LiFT（未来教师科学素养）计划提高公众科学素养，该计划旨在将未来的中学科学教师纳入真实研究。未来的教师和大学生的培养将对社会产生深远的影响。组织损伤，如由昆虫植食引起的，在植物中引发许多防御反应。在组织损伤的几分钟内开始合成植物激素茉莉酸（JA）是这些防御反应的关键，但JA的快速合成是如何实现的仍然是一个谜。该项目的主要目标是研究JA生物合成的初始步骤，以了解这些步骤是如何调节的。PI假设，相关的脂肪酶，如DEFECTIVE IN ANTHER DEHISCENCE 1（DAD 1）和GLYCEROL LIPASE A1（GLA 1）受到不同的转录和转录后调控模式的影响：后者负责JA的初始破裂，而前者则为植物防御未来的攻击做好准备。他们进一步假设，转录后激活模式发生在谷氨酸受体样（GLR）离子通道的信号传导后，该离子通道在植物范围内传播伤口反应。PI实验室开发的各种分子，遗传和分析工具将用于拟南芥和烟草的成熟模型系统，以解决以下具体目标：i）确定DAD 1和GLA 1脂肪酶对创伤引发的JA生物合成的生物化学调节，ii）鉴定和表征调节脂肪酶活性的新蛋白，和iii）确定促进系统性GLR信号传导至JA途径的空间和结构特征。脂肪酶和膜离子通道都是跨界细胞功能的基础，因此，了解这些途径如何在植物中进化将有助于了解它们在生命中的一般作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

To meet the growing needs of global food production, crop losses due to pests must be minimized. Many of pest resistance responses in plants are mediated by the hormonal signal, jasmonate (JA). The broader aim of this project is to understand plant’s built-in defense mechanisms mediated by JA as an important step toward developing sustainable pest mitigation measures. More specifically this project will elucidate the very first step(s) of JA biosynthesis and how it is linked to the perception of pest attacks by the plant cells. Available evidence points toward involvement of enzymes called lipases that hydrolyze membrane lipids as primary regulatory point. Uncovering biochemical regulation of lipases has potential applications in the food, cosmetics, detergent, and pharmaceutical industries. Additionally, membrane ion channels analogous to those involved in animal neurotransmission are involved in pest activated defense responses in plants. Learning how these elements are organized and engaged to carry out analogous functions across kingdoms is fascinating and will lead to more fundamental understanding about cell signaling. This project will contribute to STEM education and public science literacy in several ways. First, undergraduate participation in research will be promoted directly and indirectly through the PI’s core and institutional programs. Second, public science literacy will be enhanced through Sci-LiFT (Science Literacy for Future Teachers) program aimed at including future secondary school science teachers in authentic research. Training of future teachers and undergraduates will have far reaching impacts on society.Tissue injury such as that caused by insect herbivory triggers numerous defense responses in plants. The synthesis of the plant hormone jasmonate (JA) that begins within few minutes of tissue damage is key to these defense responses, but how such rapid synthesis of JA is achieved is still a mystery. The major goal of this project is to investigate the initial steps of JA biosynthesis to understand how these steps are regulated. The PI hypothesizes that the relevant lipases such as DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1) and GLYCEROL LIPASE A1 (GLA1) are subject to distinct transcriptional and post-transcriptional modes of regulation: the latter being responsible for the initial bust of JA, while the former primes the plant for defense against future attacks. They further hypothesize that the post-transcriptional mode of activation occurs after signaling from GLUTAMATE RECEPTOR LIKE (GLR) ion channels that propagate wound response plant-wide. A diverse range of molecular, genetic, and analytical tools developed in the PI’s lab will be used in the well-established model systems of Arabidopsis and Nicotiana to address following specific aims: i) determine biochemical regulation of DAD1 and GLA1 lipases for wound-elicited JA biosynthesis, ii) identify and characterize novel proteins regulating lipase activity, and iii) determine the spatial and structural features that facilitate systemic GLR signaling to the JA pathway. Both lipases and membrane ion channels are fundamental to cell function across kingdoms and thus, understanding how these pathways have evolved in plants will contribute to understanding their general roles in life.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.