The Downside of Smelling for Danger: Fitness Costs of Plant Defense Priming via Plant-Plant Volatile Signaling

植物可以探测到环境中空气中的化学物质，这些化学物质预示着即将到来的压力，并在经历压力之前做好防御准备。这种现象被称为“启动效应”。本项目通过实地观察和受控环境实验，探索启动反应的分子模式。由于生态学理论预测引种应该有成本，因此引种对植物生长、繁殖和草食率的影响的测量将用于确定引种的成本和收益。最后，将检查启动和未启动植物的后代，以确定启动植物的后代是否比未启动植物的后代具有更好的防御能力。该项目将继续“百万叶计划”，这是一个由首席研究员开发的科学研讨会，通过教授一种经验方法来测量和分析植物及其叶片所遭受的损害，向市民和小学生介绍植物与昆虫的相互作用。参与者收集自己的数据，以探索昆虫消费者对植物施加了多大的压力，从而了解植物的化学防御和感官知觉是如何进化的。这项研究的结果也可用于诱导农作物对草食有更强的抗性，从而减少虫害造成的损失。本研究的主要目的是测试两种系统发育不同的拟南芥和菜豆在控制和野外条件下与防御启动相关的适应度成本和分子模式。大量证据表明，植物对某些挥发性有机化合物（VOCs）的反应是通过“启动”（即准备）它们的防御来应对，例如来自邻近或自身远端部分的草食诱导植物挥发物（hipv）。然而，指示启动的挥发相关分子模式（VAMPs）尚不清楚。此外，生态学理论预测，诱导过程应该产生适应度成本，但目前支持这一预测的证据有限，涉及hipv介导的启动。该项目将检验以下假设：植物对hipv的反应将产生可测量的适应度成本，这将比诱导抗性的成本要低，并且hipv启动的植物将产生具有指示启动生理改变的后代（即，它们将“被启动”）。这个项目将解决我们对防御启动理解的一个关键缺口。该项目包括博士后培养、研究生培养和本科生培养。路易斯维尔大学（University of Louisville）将招收历史上代表性不足的不同群体的本科生。公民科学推广包括通过“百万叶子项目”，参与者学习量化草食动物对叶子的损害，并就植物-草食动物相互作用的生态学和进化提出自己的假设。

Plants can detect airborne chemicals in their environment that are indicative of impending stress and prepare defenses prior to experiencing the stress. This phenomenon has been termed "priming". This project explores the molecular patterns of response indicative of priming using both field observations and controlled environment experiments. Since ecological theory predicts that there should be a cost to priming, measurements of the effects of priming on plant growth, reproduction and rates of herbivory will be used to determine both the costs and benefits of priming. Finally, the progeny of primed and non-primed plants will be examined to determine if the offspring of primed plants are better defended than offspring from non-primed plants. This project will continue the "Million Leaf Project", which is a science workshop developed by the lead investigator to introduce citizens and grade school students to plant-insect interactions by teaching an experiential approach to both measure and analyze the damage experienced by plants and their leaves. Participants collect their own data to explore how much pressure insect consumers put on plants, and therefore how plant chemical defenses and sensory perception might have evolved. The results of this research may also be applied to inducing greater resistance to herbivory in agricultural crops, thereby reducing losses to pests.The principle objective of this study is to test fitness costs and molecular patterns associated with defense priming under controlled and field conditions in two phylogenetically disparate Rosids: Arabidopsis thaliana and Phaseolus lunatus. Overwhelming evidence exists that plants respond to certain volatile organic compounds (VOCs) such as herbivore-induced plant volatiles (HIPVs) from their neighbors or distal parts of themselves by "priming" (i.e., preparing) their defenses. However, the volatile-associated molecular patterns (VAMPs) indicative of priming are not well known. Moreover, ecological theory predicts that induced processes should incur fitness costs, but there is currently limited evidence to support this prediction with respect to HIPV-mediated priming. The project will test the hypothesis that plants responding to HIPVs will incur measurable fitness costs that will be less severe than costs of induced resistance, and that HIPV-primed plants will produce offspring with altered physiology indicative of priming (i.e., they will be "Primed to be Primed"). This project will address a key gap in our understanding of defense priming. The project includes post-doctoral, graduate and undergraduate training. Undergraduates will be required from a diverse population of historically underrepresented groups at the University of Louisville. Citizen science outreach is included through the "Million Leaf Project" where participants learn to quantify herbivore damage to leaves and develop their own hypotheses related to the ecology and evolution of plant-herbivore interactions.