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，必须将虫害造成的作物损失降至最低。植物对害虫的许多抗性反应是由激素信号茉莉酸(JA)介导的。这个项目的更广泛的目标是了解植物由JA介导的内置防御机制，作为开发可持续虫害缓解措施的重要一步。更具体地说，这个项目将阐明茉莉酸生物合成的第一步(S)，以及它如何与植物细胞对害虫攻击的感知联系在一起。现有证据表明，被称为脂肪酶的酶是主要的调控点，它可以水解膜脂类。揭示脂肪酶的生化调节在食品、化妆品、洗涤剂和制药行业具有潜在的应用。此外，与参与动物神经传递的膜离子通道类似，膜离子通道也参与植物中害虫激活的防御反应。了解这些元素是如何被组织和参与在王国之间执行类似的功能是令人着迷的，并将导致对细胞信号的更基本的理解。该项目将从几个方面促进STEM教育和公众科学素养。首先，将通过PI的核心和机构计划直接和间接促进本科生参与研究。第二，将通过旨在将未来中学科学教师纳入真实研究的Sci-Lift(面向未来教师的科学素养)计划来提高公众的科学素养。培养未来的教师和本科生将对社会产生深远的影响。昆虫食草性伤害等问题在植物中引发了无数的防御反应。在组织损伤后的几分钟内开始合成的植物激素茉莉酸(JA)是这些防御反应的关键，但如何如此快速地合成JA仍然是一个谜。该项目的主要目标是研究茉莉酸生物合成的初始步骤，以了解这些步骤是如何调控的。PI假设，相关的脂肪酶，如花药缺陷脱氢酶1(DAD1)和甘油脂肪酶A1(GLA1)受到不同的转录和转录后调控模式：后者负责JA的最初破坏，而前者启动植物抵御未来的攻击。他们进一步假设，转录后激活模式发生在谷氨酸受体样(GLR)离子通道发出信号后，该离子通道在整个植物范围内传播创伤反应。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成熟的模型系统，以解决以下特定目标：i)确定创伤诱导的JA生物合成中DAD1和GLA1脂肪酶的生化调节，ii)鉴定和表征调节脂肪酶活性的新蛋白质，以及iii)确定促进系统GLR信号转导JA途径的空间和结构特征。脂肪酶和膜离子通道都是跨王国细胞功能的基础，因此，了解这些途径是如何在植物中进化的将有助于理解它们在生命中的一般角色。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.