Mediation of plant-herbivore interactions by foliar bacterial endophytes: A test using a native Pseudomonas-mustard-insect interaction system

寄生虫是对动植物健康和性能影响最大的负面因素之一。植物和动物的宿主反过来又进化出强大的免疫系统，这些系统被组织成不同的分支，对不同类型的寄生虫做出反应。然而，有证据表明，当一种寄生虫的攻击激活了免疫系统的一个分支时，其他分支可以被停用。这可能意味着，不止一种寄生虫的混合感染可能会部分破坏免疫反应，仅通过增加每种寄生虫单独攻击的影响，就会产生比预期更严重的综合影响。该项目将使用落基山脉高山生态系统中的一种本地植物物种及其自然、致病细菌和食草动物来测试这一点。研究人员将进行田间和实验室实验，以证明先前感染树叶细菌是否会使植物更容易受到咀嚼树叶的草食动物的攻击，反之亦然。使用分子技术将进一步表明，这是否伴随着植物免疫系统的分支失活，这些分支分别负责对细菌和草食动物的抗性。这个项目将有助于填补我们在理解自然界中合并感染的重要性方面的一个重要空白。这个项目将培训本科生和研究生、博士后科学家和一名高中教师，学习生态学、分子生物学和微生物学。该奖项还将通过提供他的第一笔重大联邦资金来促进一名年轻调查员的职业生涯。这些研究物种是主要农业病原体、害虫和农作物的近亲，因此研究结果应该有助于理解如何减少农业损失。这项研究也应该应用于医学，因为混合感染也是人类的健康问题。例如，以前感染过肠道蠕虫的人可能会增加对微生物感染的易感性。

Parasites are among the strongest negative factors in the health and performance of both plants and animals. Plant and animal hosts have in turn evolved robust immune systems that are organized into distinct branches that respond to different types of parasites. However, evidence suggests that when attack by one type of parasite activates one branch of the immune system, other branches can be de-activated. This could mean that co-infection by more than one type of parasite could partly defeat an immune response and have more serious combined effects than expected from just adding the effects of separate attacks by each parasite. The project will test this using a native plant species and its natural, pathogenic bacteria and herbivores in an alpine ecosystem in the Rocky Mountains. The researchers will conduct field and laboratory experiments to show if prior infection with leaf-dwelling bacteria renders the plants more susceptible to attack by leaf-chewing herbivores, and vice versa. Use of molecular techniques will further show if this is accompanied by de-activation of the branches of the immune system of the plant that are respectively responsible for resistance to bacteria and herbivores. This project will help fill an important gap in our understanding of the importance of co-infection in nature.This project will train undergraduate and graduate students, postdoctoral scientists, and a high school teacher in ecology, molecular biology, and microbiology. The award will also further the career of a young investigator by providing his first major federal funding. The study species are relatives of major agricultural pathogens, pests, and crop plants, so results should help understand how to reduce agricultural losses. The research should also have applications to medicine, because co-infection is also a health problem in humans. For example, prior infection of people with intestinal worms can lead to increased susceptibility to microbial infections.