Multitrophic Manipulation of Herbivore Perception by Plants

植物不断受到昆虫食草动物的攻击。虽然植物可以通过一系列广泛的防御反应来保护自己，但它们也可以受到昆虫食草动物天敌的保护，包括寄生虫和病原体。该项目使用两种有经济价值的农作物(番茄和玉米)、两种新大陆最具破坏性的害虫(秋季粘虫和玉米穗虫)以及两类主要的害虫天敌(寄生蜂和杆状病毒)来研究植物、昆虫、食草动物及其天敌之间的三向相互作用。寄生蜂和杆状病毒在自然界中广泛存在，也可用作生防剂来防治农业害虫。从该项目中获得的知识可通过改进生物防治药剂与发展抗虫害作物的结合，对提供可持续的虫害管理产生广泛的影响。PIs将指导不同的学生群体，将多营养相互作用的概念纳入大学教材，为家庭学童和整个教育界开发关于多营养相互作用的免费在线模块，并在每年的昆虫大博览会上向数千名小学生传授这些概念。植物通过其口腔分泌物中的激发子或草食动物相关分子模式(HAMP)识别昆虫，这会触发植物防御反应。这些研究没有考虑到田间昆虫经常被杆状病毒寄生或感染。植物防御可以降低昆虫作为第三级营养水平的资源的质量。虽然寄生虫(及其共生多聚核糖核酸病毒)和杆状病毒可以操纵宿主的免疫系统，但它们是否也能改变宿主唾液腺HAMPS和效应器的产生还从未被研究过。本项目的目的是(1)确定寄生/多核糖核酸病毒和杆状病毒是否调节毛虫唾液腺和效应器的合成和活性；(2)确定杆状病毒和寄生/多核糖核酸病毒是否为了自身的利益而操纵植物防御。第三个营养级别由专家和多面手组成，因为专家天敌对寄主的生理和行为比多面手物种具有更大的控制力。因此，专家可能会对植物防御的表达产生更大的影响。将使用分子和生化分析以及生活史测量来实现这些目标。在Dawkin的扩展表型模型中，一个生物体中的一个基因对另一个生物体具有表型效应，寄生蜂和杆状病毒不仅可以控制寄主的免疫系统，还可以控制植物的免疫系统，这可能是已知的最扩展的表型之一。

Plants are under constant attack by insect herbivores. While plants can protect themselves using a wide-array of defensive responses, they can also receive protection from the natural enemies of insect herbivores, including parasitoids and pathogens. The project investigates the three-way interaction between plants, insect herbivores and their natural enemies using two economically valuable crop plants (tomato and corn), two of the most devastating insect pests in the New World (fall armyworm and corn earworm) and two key groups natural enemies of the pests (parasitoids and baculoviruses). Parasitoids and baculoviruses occur in nature and are also used as biological control agents to control pest insects in agriculture. Knowledge gained from this project may have widespread impacts on informing sustainable pest management by improving the integration of biological control agents with the development of pest resistant crop plants. The PIs will mentor a diverse group of students, incorporate concepts of multitrophic interactions into college teaching materials, develop cost-free online modules on multitrophic interactions for homeschoolers and the educational community at large, and reach thousands of elementary school children each year in the Great Insect Fair with these concepts.Plants recognize insect herbivores through elicitors or herbivore-associated molecular patterns (HAMPs) in their oral secretions, which triggers plant defensive responses. These studies have been conducted without considering that insects in the field are often parasitized or infected by baculoviruses. Plant defenses can reduce the quality of insects as a resource for the third trophic level. While parasitoids (and their symbiotic polydnaviruses) and baculoviruses can manipulate the immune systems of their hosts, whether they can also alter the host's production of salivary HAMPs and effectors has never been investigated. The aims of this project are (1) to determine if parasitoids/polydnaviruses and baculoviruses modulate the synthesis and activity of caterpillar salivary HAMPs and effectors and (2) determine whether baculoviruses and parasitoids/polydnaviruses manipulate plant defenses to their own benefit. The third trophic level will consist of both specialists and generalists because it has been postulated that specialist natural enemies exert greater control over the physiology and behavior of their hosts than generalist species. Thus specialists may have a stronger influence on the expression of plant defenses. Molecular and biochemical assays and life-history measurements will be used to address the aims. In the Dawkin's model of the extended phenotype, whereby a gene in one organism has phenotypic effects on another organism, the potential of parasitoids and baculoviruses to exert control over not just their host's immune systems, but also control over the plant's immune system could represent one of the most extended phenotypes known.