Expressed Nuclear Genes in the Plant Family Solanaceae: Unification of Phylogenetic Inference with Character Evolution

Western Michigan University, Kalamazoo MI

Investigators

Abstract

The plant family Solanaceae is one of the most economically important in the world because it contains tomato, potato, eggplant, peppers, and tobacco. Because of its great importance, many studies have been directed towards producing evolutionary-based classifications of the family; however, additional investigations are required to resolve existing ambiguities from previous research. Evolutionary-based classifications are necessary because they provide valuable frameworks that can be used to predict species that may provide valuable chemicals that are medicinally important or traits that could be useful to crop breeders. The first objective of this project by Dr. Todd Barkman of Western Michigan University is to use DNA sequences coding for the protein salicylic acid methyl transferase (SAMT) to test and refine existing evolutionary-based classifications of the tomato family. The SAMT enzyme is critical for plant survival and reproduction because it makes a chemical that is involved in pathogen and herbivore defense, and in addition in some plants, is produced by flowers as a scent compound for pollinator attraction. Because of the multiple important roles this protein plays in the tomato family, the second objective of this project is to characterize SAMT activation patterns in leaves and flowers to determine how plants have evolved the ability to manipulate the regulation of this protein for these distinct functions. This novel approach combines gene sequence data with gene activation data to provide an avenue into understanding how plants defend themselves against pathogens and herbivores but at the same time attract insects for pollination. The proposed research project will have implications for crop improvement programs aimed at enhancing activation of SAMT by artificial breeding or genetic engineering thereby leading to increased natural resistance to pathogens in tobacco, tomato, potato, eggplant, and pepper. Additionally, this project is geared towards training students in state-of-the-art research methods at Western Michigan University (WMU). In fact, much of the preliminary data for this project has been collected by an underrepresented minority undergraduate student. This student has already presented her results at 3 national meetings in the last year and is preparing to submit a manuscript for publication in a peer-reviewed journal within the coming months. These funds will allow her to complete her work on this project and serve to establish her in the field of plant science. This project will not only train undergraduates to use state-of-the-art molecular methods in a traditional classroom setting, it will involve training of undergraduate and graduate students in a rigorous research setting to provide data that will be important for improving crop plant production.