Knowledge of how changes at the genetic level cause species to have different features is still rudimentary. The proposed research will elucidate the genes responsible for differences in the architecture of wild relatives of cabbage (Brassicaceae). The genetic model species Arabidopsis thaliana produces flowers on an elongated portion of stem called an inflorescence. In contrast, species of Leavenworthia produce flowers on long stalks directly from the cluster of leaves close to the ground, the rosette. Prior NSF funded research has suggested that a gene called LFY changed during the evolution of Leavenworthia and that it may have played a role in the evolution of rosette flowering from inflorescence flowering. The proposed research we will further test this hypothesis by isolating the LFY gene from other rosette flowering and inflorescence flowering species and introducing them into A. thaliana. Additionally, other candidate genes that plausibly contributed to the evolution of rosette flowering will be studied. The characteristics of A. thaliana plants that contain single or multiple Leavenworthia genes we be used to determine which sets of genes played the most important role in architectural evolution. Lastly, the researchers will begin developing techniques for introducing genes into Leavenworthia, thereby allowing more powerful experimental tests to be used in the future. By clarifying the genetic basis of architectural evolution in Brassicaceae, the research will enhance understanding of basic principles of plant development. This information may help plant breeders more effectively manipulate crop plants and will provide insights into general mechanisms of developmental evolution. Additionally, the research program will provide valuable research opportunities for undergraduates and one minority graduate student.
