DISSERTATION RESEARCH: Ecological and Evolutionary Consequences of Natural Selection by Herbivores on Solidago altissima Defense Strategies

Cornell University, Ithaca NY

Investigators

Abstract

Plants defend themselves against herbivores in many different ways, including some defenses that are always expressed, and others that are only expressed when an herbivore is attacking. In order for a plant to best use its resources, defenses expressed only when an herbivore attacks should be effective against that herbivore, and ineffective defenses should not be expressed at that time. This project addresses the specific elicitation and biological function of antidigestive proteins induced by different herbivores in goldenrod plants. The project will study the expression of specific defenses expressed in response to herbivore attack by treating plants with two types of natural herbivores (a generalist and a specialist) and mechanical damage. Furthermore, the study will address the impact of herbivory on the evolution of specific plant defense responses by comparing plants from plots of a long-term herbivore-exclusion treatment and control plots exposed to natural herbivore attack. Hypothetically, long-term herbivore removal will select for plants with defense responses to herbivory that are more generalized or smaller in magnitude. Understanding the complexity of plant responses to herbivory is not only necessary to explore plant defenses as a strategy in sustainable pest control in agriculture but will also pave the way for understanding the adaptive value of induced defenses. This project will look at natural variation, and will study the effects of natural selection by herbivores on plant traits of herbivore resistance. It will allow training of undergraduate students in the field of Molecular and Chemical Ecology that has been identified as one of the focus fields of ecological research at Cornell. Results and plants from the study will be used as a resource for undergraduate classes.