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，大多数植物都有被昆虫咀嚼、开采或以其他方式吃掉的迹象。另一种侵袭者-真菌和细菌-也很常见，可能因为它对供人食用的蔬菜的影响而为人所熟知；这些病原体会造成黑点、枯叶或其他腐烂迹象。由于每种类型的攻击者在自然界中都很常见，植物已经进化出防止或将其造成的损害降至最低的方法。但是，就像万能的人不会掌握任何东西一样，植物很难同时防御所有类型的攻击者。也就是说，被细菌感染的植物往往更容易受到昆虫的影响，反之亦然。这些现象被称为权衡--原本有益于有机体的行为或反应之间的负面相互作用--它们的进化起源和生态后果尚不清楚。这个项目探索本地植物是否受到昆虫和细菌防御的权衡，以及个别植物的防御状态如何影响相同植物的整个种群对攻击的反应。先前的结果表明，细菌丰度与采叶蝇对当地植物苦菜野生种群的攻击之间存在正相关。该项目将把细菌对苦菜及其食草动物的生态影响与植物化学和防御系统的变化联系起来，这些变化可能是观察到的影响的基础，以及细菌中可能指导特定植物防御系统的基因和基因产物。已经在许多种类的农作物中发现了这种防御权衡的证据，在实验室条件下也观察到了同样的证据，但缺乏本土植物及其野生细菌和昆虫攻击者的例子。通过在自然条件下使用野生物种，这个项目将检验这样一个假设，即叶栖细菌在昆虫和植物之间的关系中扮演着无处不在但神秘的第三方角色。结果将有助于为全世界农业系统中的害虫和病原体的管理提供信息，这显然与粮食安全有关。此外，研究人员还将指导本科生收集和解释数据，并将在公立学校工作，与教师和高中生分享他们的结果。