The Arabidopsis thaliana genome contains 24 related genes that encode methyltransferase enzymes distinct from any other known methyltransferases. One methyltransferase from this group has been shown to convert jasmonic acid, an important plant hormone, into the jasmonate methyl ester, thereby changing the activity of the hormone in significant ways. Preliminary experiments suggest that the other 23 methyltransferases of this group convert several important hormones and other plant constituents into the methyl esters, thereby exerting important effects on the biological activity of these molecules and consequently on myriad important physiological processes. The aim of this project is to identify the function of all the methyltransferases of this group (i.e., which compound each of them methylates) by a combination of methods that involve molecular genetics, enzymology, protein structure analysis, and metabolite profiling. The consequences of the methylation of such hormonal molecules on the physiology of the plant will be examined in selected cases, which may include processes involving plant response to pathogens, drought conditions, and herbivory. The results are expected to provide a better understanding of plant responses to environmental conditions, thus helping improve crop yield and nutritional value. In addition, by developing methodologies for determining which Arabidopsis genes are involved in the synthesis of the plant's diverse repertoire of small molecules, the project will contribute to the elucidation of the function of other Arabidopsis genes involved in hitherto unknown biochemical pathways.
Broader Impact: The project will provide interdisciplinary opportunities for training undergraduates, graduates, and post-docs, including women and minorities. All three institutions involved in this project have formal programs to attract minority undergraduate and high school students to faculty labs, and such students will be actively recruited. In addition, methods and materials developed in this investigation will be used directly to train undergraduate students in formal lab courses taught by the lead investigators. The resources generated in the project will be made available through the Arabidopsis Biological Resources Center. The data obtained will be disseminated by publications in scientific journals, by deposition in the public databases including the Arabidopsis Information Resource, NCBI, and the Protein Data Bank, and by monthly updating of the project's website, http://biology.lsa.umich.edu/research/labs/pichersky/NSF2010.
