Dynamics of a Native Iris-Herbivore Association: Effects of Salinity, Herbivory, and Genetic Variation

该项目将调查在一系列盐度条件下生长的本地鸢尾种群和草食动物中不同类型的植物胁迫之间的相互作用。 盐胁迫和植食性胁迫都是植物胁迫的重要来源，都能诱导植物产生脱落酸（阿坝）和茉莉酸（JA）。 这些激素在植物个体间的产生变化似乎受到遗传的影响。 胁迫诱导反应的大小直接影响植物的生长和繁殖以及对植食动物攻击的抗性。 该项目将田间实验与实验室分析相结合，以1）检查植物激素诱导与鸢尾和草食动物性能之间的关系，2）量化鸢尾和草食动物种群中的基因流和遗传结构，3）确定鸢尾和鸢尾草食动物是否局部适应其微环境。 阿坝和JA都是影响植物对环境和植食性介导的胁迫的耐受性的生长调节剂。 因此，该项目的结果具有重要的经济意义。这项研究将是第一个确定的浓度和波动的压力诱导阿坝和JA在一个自然的植物种群，因此可以推进我们的一般理解植物激素在植物抗逆性中所发挥的作用。 植物对害虫和病原体的抗性是基于遗传和环境的。 通过量化盐胁迫和确定植物和草食动物种群的遗传结构，这项研究可以确定哪些植物基因型与耐盐性和敏感性相关，以及草食动物基因型与毒性相关。 然后，可以将此信息应用于压力容限是重要组成部分的托管系统。

This project will investigate the interaction between different types of plant stress in a population of native iris growing under a range of salinity conditions and herbivory. Both salinity and herbivory can be important sources of plant stress, and both can induce the production of abscisic acid (ABA) and jasmonic acid (JA). Variation in the production of these hormones among individual plants appears to be genetically influenced. The magnitude of the stress induction response can directly affect plant growth and reproduction as well as resistance to herbivore attack. This project combines field experiments with laboratory analyses to 1) examine the relationship between phytohormone induction and iris and herbivore performance, 2) quantify gene flow and genetic structure in the iris and herbivore populations, and 3) determine if iris and iris herbivores are locally adapted to their microenvironment. Both ABA and JA are growth regulators that influence plant tolerance to environmental and herbivore-mediated stress. Thus the results of this project have important economic implications. This study will be the first to determine the concentrations and fluctuations of stress-induced ABA and JA in a natural plant population, and can therefore advance our general understanding of the role played by phytohormones in plant stress tolerance. Plant resistance to pests and pathogens is both genetically and environmentally based. By quantifying salinity stress and determining the genetic structure of the plant and herbivore populations, this study can determine what plant genotypes are associated with tolerance and susceptibility to salinity and herbivory stress, as well as the herbivore genotypes associated with virulence. This information can then be applied to managed systems in which stress tolerance is an important component.