COLLABORATIVE RESEARCH: EAGER: Evolution of Plant Defense: A Multigenerational Selection Experiment in the Field

植物是几乎所有食物链的基础，它们负责养活世界。换句话说，植物直接(通过食草动物)或间接(因为食肉动物吃草食动物)提供维持所有动物生命所需的能量。由于这种对植物的巨大压力，它们进化出了不同的策略来防御被消耗。例如，植物具有各种可遗传的物理(如刺、刺)和化学(如氰化物等毒素)特征，可抵御食草动物。理论、观察和实验都表明，昆虫食草动物是影响植物特征进化的关键因素。然而，植物种群如何在多个世代中实时地对这种选择做出反应，实际上是未知的。该项目将利用新开发的分子技术对月见草属植物(Oenthera Biennis)的遗传个体进行指纹分析，以解决目前科学认识上的这一重大差距。由于这个项目将在包含已知遗传特性的植物受到昆虫食草性或受昆虫食草性保护的田间地块进行，研究人员将对在自然环境条件下因昆虫食草动物攻击而进化的一般进化过程和特定特征获得新的见解。这个项目将是迄今为止对植物防御进化进行的最严格的调查之一，并将评估草食动物对植物化学防御和种群遗传组成变化的影响。此外，还将确定昆虫群落对植物种群遗传构成变化的反应。这项研究的广泛影响包括针对K-12学生、本科生、研究生和普通公众的教育努力。由于拟议的工作考察了相对较短的时间范围内的演变变化，教师和普通公众的参与可以很容易地通过外联努力和实地考察来实现。自然选择和植物-食草动物相互作用的进化信息将通过康奈尔大学(康奈尔生物教师研究所)的一个既定计划被带到K-12课堂。

Plants, being at the base of almost all food chains, are responsible for feeding the world. In other words, plants provide the necessary energy to sustain all animal life either directly (through herbivory) or indirectly (because carnivores eat herbivores). Because of this tremendous pressure on plants, they have evolved a remarkable diversity of strategies to defend against being consumed. For example, plants possess a variety of heritable physical (e.g., thorns, spines) and chemical (e.g., toxins such as cyanide) traits that ward off herbivores. Theory, observations, and experiments have all implicated insect herbivores as key agents shaping the evolution of plant traits. How plant populations respond to this selection in real time over multiple generations, however, is virtually unknown. This project will address this major gap in current scientific understanding with newly developed molecular techniques to fingerprint genetic individuals of the common evening primrose (Oenothera biennis). Because this project will be conducted in field plots containing plants of known genetic identity either subjected to or protected from insect herbivory, the investigators will gain new insight into both the evolutionary process in general and the specific traits that evolve in response to insect herbivore attack under natural environmental conditions. This project will be one of the most rigorous investigations of the evolution of plant defense performed to date, and will assess the impact of herbivores on changes in plant chemical defenses and genetic composition of the population. In addition, responses of the insect community to changes in the genetic make-up of the plant populations will be determined.Broader impacts of this study include educational efforts directed to K-12 students, undergraduates, graduate students, and the general public. Because the work proposed examines evolutionary changes over relatively short time scales, engaging teachers and the general public can be readily accomplished through outreach efforts and field trips. The message of evolution by natural selection and plant-herbivore interactions will be taken into K-12 classrooms via an established program at Cornell University (Cornell Institute for Biology Teachers).