DISSERTATION RESEARCH: Genetic Effects of Plant Defense on Above- and Below-ground Ecological Interactions and Natural Selection

论文研究：植物防御对地上和地下生态相互作用和自然选择的遗传效应

• 批准号: 1701790
• 负责人: Thomas Mitchell-Olds
• 金额: $ 2.06万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701790&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Genetic; Effects; Plant

Using a plant species native to the Rocky Mountains in the mustard family, Boechera stricta, the investigators will test how differences in mechanisms of natural selection across environments influences the maintenance of variation of natural plant chemical defenses. In natural populations, the persistence of variation of traits among individuals allows for adaptation to occur. Despite the central role of variation in the process of adaptation, it is poorly understood how and why variation persists in the face of natural selection eliminating less fit varieties. Chemical defense strategies (various types and concentrations of mustard oils) are highly variable across natural populations of the study species. These defensive compounds have known ecological effects, both as deterrents of insect feeding on leaves (above-ground effects) and as drivers of microbial community composition in the soil (below-ground effects). The researchers will test how plant growth and reproduction are influenced by the above- and below-ground effects of different chemical defense strategies on plant-insect and plant-microbe interactions. The project provides opportunity for undergraduate training. Planned outreach activities will target middle and high school students, and also the general public during the Crested Butte Wildflower Festival.The pleiotropic effects of plant defensive chemicals and the genes that underlie them are well documented. In addition to influencing fitness by mediating herbivory in aboveground environments, defensive chemicals can affect microbial communities in the soil immediately surrounding root tissue. It is likely that interactions between above- and belowground selective pressures influence overall patterns of natural selection on plant chemistry. The investigators will test for pleiotropic above- and belowground effects of a chemical defense gene utilizing near-isogenic lines of the ecological model species, Boechera stricta (Brassicaceae), that vary in a gene controlling mustard oil biosynthesis to. They will first characterize the effects of defensive chemical profiles on microbial community assembly in the rhizosphere. Second, they will assess how rhizosphere selection affects plant fitness. Finally, they will test how the belowground context may modify aboveground effects of mustard oils as anti-herbivore defenses, and how interactions between the above- and belowground fitness effects of mustard oils result in the maintenance of genetic and trait diversity over space and time.

Boechera Stricta使用芥末家族中落基山的植物物种，研究人员将测试自然选择机制跨环境的差异如何影响维持天然植物化学防御的变化。在自然种群中，个体之间特征变化的持久性允许进行适应。尽管变异在适应过程中的核心作用，但面对自然选择消除较不拟合品种的自然选择中的变化如何以及为什么持续存在差异。化学防御策略（芥末油的各种类型和浓度）在研究物种的自然种群中是高度可变的。这些防御性化合物具有已知的生态作用，既是对叶子的昆虫进食（地面效应）的威慑作用，也是土壤中微生物群落组成的驱动因素（地下效应）。研究人员将测试植物生长和繁殖如何受到不同化学防御策略对植物诱导和植物 - 微生物相互作用的上述和地下影响的影响。该项目为本科培训提供了机会。 计划的外展活动将针对中学生和公众在冠冕的野花节上。除了通过在地上环境中介导草食性来影响健康外，防御性化学物质还会影响立即围绕根组织的土壤中的微生物群落。上层和地下选择压力之间的相互作用可能会影响植物化学上自然选择的总体模式。 研究人员将利用生态模型物种Boechera stricta（胸腺科）的近乎异源线的化学防御基因的多效性在地上和地下作用，在控制芥末油生物合成的基因中有所不同。他们将首先表征防御性化学特征对根际微生物群落组装的影响。其次，他们将评估根际选择如何影响植物健身。最后，他们将测试地下环境如何将芥末油作为抗毛发动物防御的地面影响以及芥末油的上述和地下适应性之间的相互作用如何导致维持时间和时间上的遗传和性状多样性。