Ecology and Evolution of Young Leaf Defenses in Tropical Rainforest Legumes

植物和食草动物构成了地球生物多样性的大部分，它们之间的相互作用没有任何地方像热带森林那样强烈。食草动物和植物之间的进化相互作用导致了一场“军备竞赛”，在这场竞赛中，植物防御方面的创新受到了食草动物的反适应。例如，植物有一系列的物理、化学和物候防御，帮助保护它们的叶子免受食草动物和病原体的侵害。食草动物有一系列惊人的机制来避免、排毒，甚至利用植物防御来为自己的利益服务。尽管人们普遍认为植物和食草动物的许多特征是“军备竞赛”的结果，但我们对导致新防御进化的潜在进化机制或生态条件知之甚少。为了解决这一问题，我们将研究豆科雨林树木的防御措施，量化各种防御措施，包括生物碱，测量食草动物的食叶率，并表征食草动物的生长和防御特征。这项工作将在巴拿马的史密森热带研究所和犹他大学进行。这项基础研究对于理解自然选择如何促进新的防御机制的进化，以及为什么防御机制往往在不同的植物物种中共同发生，以及植物防御机制如何限制以其为食的食草动物的行为、生长和防御是必要的。此外，该研究还应用于森林管理，以及利用野生植物的基因和防御性化合物开发药物和农作物。

DEB-0108150 ColeyPlants and herbivores comprise the majority of the earth's biodiversity, and nowhere are their interactions as intense as in tropical forests. The evolutionary interactions between herbivores and plants has led to an "arms race" in which innovations in plant defenses are met by counter adaptations on the part of herbivores. For example, plants have a battery of physical, chemical and phenological defenses which help to protect their leaves against herbivores and pathogens. And herbivores have a staggering array of mechanisms for avoiding, detoxifying and even using plant defenses for their own benefit. Despite the wide acceptance that many traits of plants and herbivores result from an "arms race", we know very little about the underlying evolutionary mechanisms or ecological conditions that would lead to the evolution of novel defenses. To address this, we will study the defenses of rainforest trees in the family Leguminosae, quantifying various defenses, including alkaloids, measuring rates of leaf-feeding by herbivores and characterizing growth and defensive traits of herbivores. The work will be conducted at the Smithsonian Tropical Research Institute in Panama and at the University of Utah. This basic research is necessary for understanding how natural selection favors the evolution of novel defenses as well as why suites of defenses tend to co-occur in different species of plants, as well as how plant defenses may constrain the behaviors, growth and defenses of the herbivores that feed on them. In addition, the research has applications for forest management, and for the development of medicinal drugs and agricultural crops using genes and defensive compounds from wild plants.