Disease Resistance Genes

Understanding genetic mechanisms of legume disease resistance genes

The legume family, or Fabaceae, is one of the largest and most diverse plant families. Three species, Medicago truncatula, Lotus japonicus and soybean, have emerged as reference species for investigating the generic properties of legumes. Research in this project, performed in collaboration with Doug Cook and colleagues at the University of California, Davis, Dr. May and Andrew Farmer, leverages knowledge gained in the reference legumes to develop a broad infrastructure for comparative genomics, including representatives from the key phylogenetic nodes in which reside almost all of the economically important legume species. Understanding diversity of legume resistance genes is the primary goal of this work. Among the outcomes will be a road map that links genomic landmarks between related species, yielding genetic tools of use to basic research. One such product will be the cloning and genetic mapping of the majority of disease resistance genes in each of the target species, resulting in a comprehensive candidate gene resource. Currently legumes provide an estimated 33% of the protein in the human diet. The significance of legumes to human society is evidenced by their importance as commodities in the US; soybean and alfalfa, for example are major economic entities, while a diversity of grain legumes occupy part of the staple diet of US citizens. Although knowledge of genome content and structure could enable improved strategies for basic and applied research in each of the various legume species, their sheer number precludes a systematic in-depth analysis of each of their genomes. Each species selected for this project is of economic importance in the US and/or in the developing countries of Africa and in India. An ancillary goal of this project is to enhance opportunities for genomics-enabled breeding and biotechnology in legumes generally. This work is supported by the National Science Foundation.