EAGER: Leucine Aminopeptidase - Regulator of the Stress-Induced Stromal Proteome

世界上超过40%的粮食供应因病原体、害虫和杂草造成的破坏而损失。因此，提高植物生产力和抗虫害能力的新战略将大大提高世界粮食供应的安全性。为了实现这一目标，需要深入了解控制昆虫抗性的机制。该项目处于植物-昆虫相互作用的最前沿，将揭示叶绿体如何与细胞核通信，以协调受伤和昆虫攻击后的强大防御;这些知识将使未来的抗虫新策略成为可能。这个项目是培养研究生的沃土。研究生的领导能力将通过指导本科生在这个项目中发展。UCR是一个为少数民族服务的机构，该项目将招募和吸引不同背景的学生。该项目的成果将通过在科学期刊上发表文章、在滨江K-12学校和公众中进行的非专业讲座以及在会议和大学中进行的讲座进行传播。该项目将研究番茄叶绿体定位蛋白质亮氨酸氨肽酶（LAP-A）的重要性及其在昆虫进食和受伤后产生控制核基因表达的信号中的作用。该项目将确定LAP-A依赖的信号，介导这种叶绿体到细胞核的通信。将鉴定LAP-A作用的蛋白质/肽（靶标），并且靶标可以是信号或可以产生信号。LAP-A有两项活动。LAP-A是氨肽酶，并且可以通过修饰位于叶绿体中的靶蛋白/肽的N-末端来产生信号。LAP-A也是一种分子伴侣，可以帮助靶标保持活跃的折叠状态。这些活动应该影响目标的结构、活性和/或稳定性，从而影响信号产生。该项目将使用尖端的蛋白质组学技术来测量表达不同水平LAP-A（LapA沉默，LapA过度表达和野生型）的三种番茄品系中的蛋白质/肽。目的1将鉴定（1）被LAP-A切割和（2）具有与LAP-A的存在/不存在严格相关的改变的稳定性的叶绿体蛋白。目的2将确定LAP-A依赖的变化，在一个小肽称为谷胱甘肽（GSH）。初步数据链接LAP-A和GSH周转。GSH是一个很好的候选信号，因为它调节其他系统中的两个防御信号（活性氧和氧化还原状态）。LAP-A靶点的确定将揭示LAP-A产生的介导叶绿体-核通讯的信号的性质。

Over 40% of the world's food supply is lost to damage caused by pathogens, pests and weeds. Therefore, novel strategies to enhance plant productivity and resistance to pests will significantly increase the security of the world's food supply. To achieve this goal, a deep understanding the mechanisms that control resistance to insects is needed. This project is at the cutting edge of plant-insect interactions and will reveal how chloroplasts communicate with nuclei to coordinate a robust defense after injury and insect attack; this knowledge will enable new strategies for insect resistance in the future. This project is a fertile training ground for a graduate student. Graduate student leadership skills will be developed through guiding undergraduate's in this project. UCR is a minority-serving institution and this project will recruit and engage students with diverse backgrounds. Results from the project will be disseminated by publications in scientific journals, lay talks to Riverside K-12 schools and the public, and talks at meetings and universities.This project will study the importance of a tomato chloroplast-localized protein called leucine aminopeptidase (LAP-A) and its role in generating a signal that controls nuclear gene expression after insect feeding and wounding. This project will identify the LAP-A-dependent signal that mediates this chloroplast-to-nucleus communication. The protein/peptide (target) that LAP-A acts on will be identified and the target may be the signal or may create the signal. LAP-A has two activities. LAP-A is an aminopeptidase and may produce the signal by modifying the N-terminus of a target protein/peptide that resides in the chloroplast. LAP-A is also a molecular chaperone and may help targets stay in an active folded state. These activities should influence the target's structure, activity and/or stability and thereby signal production. This project will use cutting-edge proteomics technologies to measure proteins/peptides in three tomato lines that express different levels of LAP-A (LapA-silenced, LapA-overexpressing, and wild type). Aim 1 will identify chloroplast proteins that are (1) cut by LAP-A and (2) have altered stability that is strictly correlated with the presence/absence of LAP-A. Aim 2 will determine the LAP-A-dependent changes in a small peptide called glutathione (GSH). Preliminary data link LAP-A and GSH turnover. GSH is an excellent candidate for the signal as it regulates two defense signals (reactive oxygen species and redox status) in other systems. The identity of LAP-A's targets will reveal the nature of the LAP-A-generated signal that mediates chloroplast-nucleus communication.