Evolutionary History of Defense Genes in the Genus Zea and Family Poaceae: Insight from DNA Sequence Data

The mechanisms by which plants defend themselves against herbivores and pathogens have been subject to extensive investigation in contemporary populations. In comparison, relatively little is known about the long-term evolutionary dynamics of plant defenses. This research will use the information contained in DNA sequences to investigate these long-term dynamics. DNA sequence diversity of defense genes in three Zea species, including the domesticate Z. mays ssp. mays (corn), and divergence of defense genes among different genera of grasses will be analyzed. These analyses will provide an unprecedented picture of the evolutionary history and present day diversity of plant defense genes.

In addition to advancing our understanding of plant evolution, the results from this research may be very valuable to agriculture. For example, the extensive sampling of defense alleles may identify genetic resources useful for developing sustainable means of pest control. This research may identify plant defenses that are evolutionarily stable and, thus, may provide durable resistance against parasites. Analysis of inter- and intra-population diversity will provide data necessary for developing efficient strategies for collecting genetic resources for conservation and crop improvement. Graduate and undergraduate students will participate in the proposed research and will have opportunities to learn molecular techniques and molecular-evolutionary analyses.