DISSERTATION RESEARCH: Dissecting microbial mediation of plant-herbivore interactions in the wild

论文研究：剖析野生植物与食草动物相互作用的微生物介导

• 批准号: 1309493
• 负责人: Noah Whiteman
• 金额: $ 1.91万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1309493&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Dissecting; microbial; mediation

If one looks closely, most plants bear some signs of having been chewed, mined, or otherwise eaten by insects. Another form of attacker, fungus and bacteria, is also common, and may be familiar through its effects on vegetables intended for human consumption; these pathogens create black spots, wilted leaves, or other signs of rot. Because each type of attacker is so common in nature, plants have evolved means of preventing or minimizing the damage they inflict. But just as the jack-of-all-trades is master of none, plants have difficulty defending themselves against all types of attacker simultaneously. That is, plants infected with bacteria are often more susceptible to insects, and vice versa. These phenomena are called trade-offs?negative interactions between behaviors or responses that otherwise benefit organisms?and their evolutionary origins and ecological consequences remain unclear. This project explores whether native plants are affected by a trade-off in defense against insects and bacteria, and how the defense status of individual plants affects how entire populations of the same plants respond to being attacked. Prior results show a positive association between bacterial abundance and attack by a leaf-mining fly across a wild population of a native plant, bittercress. This project will link the ecological impact of bacteria on bittercress and its herbivores to changes in plant chemistry and defenses that may underlie the observed effects, as well as genes and gene products in bacteria that may direct particular plant defenses. Evidence for this defense trade-off has been found for many species of crops and likewise has been observed in laboratory conditions, but examples for native plants and their wild bacterial and insect attackers are missing. By using wild species in natural conditions, this project will provide a test of the hypothesis that leaf-dwelling bacteria act as a ubiquitous but cryptic third player in the relations between insects and plants. Results will help inform management of pests and pathogens in agricultural systems worldwide, with clear relevance to food security. Also, the researchers will mentor undergraduate students in collection and interpretation of data, and will work in public schools to share their results with teachers and high school students.

如果仔细观察，大多数植物都有一些被昆虫咀嚼，开采或以其他方式食用的迹象。攻击者，真菌和细菌的另一种形式也很常见，并且可能会因其对供人类消费的蔬菜的影响而熟悉。这些病原体会产生黑斑，枯萎的叶子或其他腐烂迹象。由于每种类型的攻击者在性质上都是如此普遍，因此植物已经进化出了预防或最大程度地减少造成的损害的手段。但是，正如万能的千斤顶是无主的一样，植物也很难同时捍卫所有类型的攻击者。也就是说，感染细菌的植物通常更容易受到昆虫的影响，反之亦然。这些现象称为权衡？行为或反应有益于生物体的反应之间的负相互作用？及其进化起源和生态后果尚不清楚。该项目探讨了本地植物是否受到防御昆虫和细菌的防御的影响，以及单个植物的防御状况如何影响同一植物的整个种群对攻击的反应。先前的结果表明，细菌丰度与叶片蝇蝇的攻击之间存在正相关，该蝇蝇在本地植物的野生植物的野生种群中。该项目将将细菌对苦丝及其食草动物的生态影响与植物化学和防御的变化联系起来，这些变化可能是观察到的作用的基础，以及细菌中可能指导特定植物防御的基因和基因产物。已经发现了许多农作物的这种防御权衡的证据，并且在实验室条件下也观察到了同样的证据，但是本地植物及其野生细菌和昆虫攻击者的例子却缺失了。通过在自然条件下使用野生物种，该项目将检验以下假设：叶叶细菌在昆虫与植物之间的关系中充当无处不在但隐性的第三名参与者。结果将有助于告知管理全球农业系统中的害虫和病原体，并明确与粮食安全有关。 此外，研究人员还将指导本科生收集和解释数据，并将在公立学校与教师和高中生分享结果。