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. The research in this project leverages knowledge gained in the reference legumes to develop a broad infrastructure for comparative genomics, including representatives from the key phylogenetic nodes of the Papilionoid subfamily in which reside almost all of the economically important legume species. Understanding Papilionoid genome evolution, particularly the evolution of resistance genes, is the primary goal of this work. Among the outcomes will be a road map that links ancestral genomic landmarks between related species, providing insight into the evolution of these species and 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 of nucleotide binding site - leucine-rich repeat (NBS-LRR) proteins. We expect to gain insight into the timing of resistance gene radiation relative to speciation; the identification of ancient and stable, versus recently derived and fast-evolving, resistance genes; the nature of specific evolutionary processes and whether they operate symmetrically across taxa; the history and frequency of specific mechanisms for resistance gene and resistance gene-cluster variation across the legume family.

Resources to be generated by the project include: (1) comparative genetic maps between legume genomes based on orthologous gene markers, (2) deep coverage Bacterial Artificial Chromosome (BAC) libraries and moderate coverage BAC end sequence data to facilitate gene discovery, (3) species-specific genetic markers that link BAC clones to genetic intervals, and (4) a complete inventory of resistance gene homologs for each of give legume species.

Broader Impacts 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.

Access to project outcomes Project data will be deposited in public databases at the National Center for Biotechnology Information (http:www.ncbi.nlm.nih.gov) and available from a project web site accessible through http://medicago.ucdavis.edu. BAC libraries will be available from the Arizona Genomics Institute (www.genome.arizona.edu/).

Agency
National Science Foundation (NSF)
Institute
Division of Integrative Organismal Systems (IOS)
Application #
0605251
Program Officer
Diane Jofuku Okamuro
Project Start
Project End
Budget Start
2006-08-01
Budget End
2011-07-31
Support Year
Fiscal Year
2006
Total Cost
$4,959,892
Indirect Cost
Name
University of California Davis
Department
Type
DUNS #
City
Davis
State
CA
Country
United States
Zip Code
95618