Leucine Aminopeptidase: A Regulator of the Late Branch of Wound Signaling

这一建议的重点是了解番茄亮氨酸氨基肽酶A （LapA）。LAP控制番茄伤人后的防御和昆虫取食。当LAP蛋白在转基因LapA-SI植物中减少时，拮抗昆虫生长的蛋白质和化学物质的产生水平降低。与野生型植物的昆虫相比，LapA-SI植物遭受的伤害更大，烟草角虫更大。此外，在产生过量LAP-A蛋白（LapA-OX）的植物上，毛虫消耗的叶子较少，幼虫数量减少。LapA-OX植株提供了一个重要的新的抗虫机制，因为植株的高度和肥力没有受到损害。了解LAP-A如何控制番茄防御将是我们对植物基因调控的一般知识的重要补充。目标1是确定LapA-SI和LapA-OX植物对使用不同取食方式的昆虫的敏感性或抗性。如果LapA-OX植物对许多昆虫具有抗性，那么就将发现一种重要的保护植物免受害虫侵害的新机制。目标2是利用遗传、生化和植物转化技术来确定LAP-A的肽酶活性是否对其控制昆虫防御的作用至关重要。这一点很重要，因为来自其他生物体的lap具有多种功能。最后，目标3是确定由LAP-A调控的细胞过程。提出了一种将影响番茄伤害的多种信号与LAP-A联系起来的新模型。该模型将使用分子、生化和转基因植物策略进行严格测试。通过支持或反驳这一模型，这些实验将有助于定义植物用来抵御昆虫的复杂且基本上未被探索的防御网络。这些研究应该会产生新的策略，在作物和园艺植物中设计一种环境安全的抗虫性，从而使农业和整个社会受益。拟议的实验范围从整个生物体研究到分子反应，跨越植物生物学和昆虫学领域。该研究项目将为研究生、本科生和博士后提供独特的跨学科培训环境。

This proposal focuses on understanding the tomato leucyl aminopeptidase A (LapA). LAP controls tomato defenses after wounding and insect feeding. When LAP protein is reduced in transgenic LapA-SI plants, the proteins and chemicals that antagonize insect growth are produced at lower levels. LapA-SI plants incur more damage and tobacco hornworms are larger relative to insects from wild-type plants. In addition, on plants that make excessive amounts of LAP-A protein (LapA-OX), caterpillars consume less foliage and larval masses are reduced. The LapA-OX plants provide an important and new mechanism of insect resistance, since plant stature and fertility are not impaired. Understanding how LAP-A controls tomato defenses will be an important addition to our general knowledge of gene regulation in plants. Goal 1 is to determine the susceptibility or resistance of LapA-SI and LapA-OX plants to insects that use different modes of feeding. If LapA-OX plants provide resistance to many insect species, an important and new mechanism to protect plants from insect pests will have been discovered. Goal 2 is to use genetic, biochemical and plant transformation technologies to determine if the peptidase activity of LAP-A is essential for its role in controlling defenses against insects. This is important since LAPs from other organisms have multiple functions. Finally, Goal 3 is to determine the cellular process that is regulated by LAP-A. A new model that links the many signals that influence wounding in tomato and LAP-A is proposed. This model will be rigorously tested using molecular, biochemical and transgenic plant strategies. By supporting or refuting this model, these experiments will aide in defining the complex and largely unexplored defense network that plants employ against insects. These studies should result in new strategies for engineering an environmentally safe resistance to insects into crops and horticultural plants, benefiting agriculture and society at large. The proposed experiments range from whole organism studies to molecular responses and spans the fields of plant biology and entomology. This research program will provide a unique, interdisciplinary training environment for a graduate and undergraduate students and a postdoctoral fellow.