| Abstract Detail
Thursday Afternoon Breeding and Variation Baker, Barbara [1], Brown, C.R. [2], Zhang, Linhai [3], Jiang, Jiming [4], Buell, CR [5], Kuang, Hanhui [1]. Comparative Genomics: Insight into Evolution of Plant Innate Immunity in Solanaceae. WILD Solanum species, including the allohexaploid Solanum demissum and diploid S. bulbocastanum, have been the source of several important disease resistance traits introduced into cultivated S. tuberosum. We investigated the structural, functional and evolutionary properties of three pathogen disease resistance loci of S. demissum using comparative genomics. Our studies focused on understanding features of clustered arrays of R gene sequences and the identification of other sequences common to resistance hotpots for specifying qualitative and quantitative resistance and generating novel pathogen disease resistance genes. We physically mapped (~15Mb total) and sequenced (~3.5 Mb total) portions of each of the three S. demissum resistance hotspots on Chromosome 5 (R1, Nb region), the lower arm of Chromosome 11 {R3a, R3b and R5-11 region, termed the Major Late Blight locus (MLB)} and the upper arm of Chromosome 11 (Rmci, N region) (see: http://www.potatogenome.org/nsf5/ and http://www.tigr.org/tdb/potato/disease_db.shtml). We found that these three resistance gene clusters exhibit variations in overall length and number of resistance gene copies between haplotypes of S. demissum and that resistance gene homologues clustered at each of the three hotspots belong to either the fast-evolving Type I R-genes or slow evolving Type II R-genes. Our comparative analyses suggests that a common mechanism could account for both the differentiation of Type I and Type II groups and differentiation of related Type I R-gene groups at each locus. Comparative analyses of the R-gene loci among Solanaceae genomes also revealed the presence of several families of miniature inverted repeat transposable elements (Sol-MITEs). The structural, functional and evolutionary impact of these transposons with respect to pathogen defense and resistance and evolution of diversity among the Solanaceae will be discussed.
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Related Links:
NSF Potato Genome Project
Solanaceae Disease Resistance (SOLR) Gene Database
NSF Potato Functional Genomics
1 - USDA-ARS/UC-Berkeley, Plant Gene Expression Center, 800 Buchanan Street, Albany, CA, 94710
2 - US Dept. of Agriculture/ARS, Prosser, WA, 99350, USA
3 - Washington State University, 24106 N. Bunn Rd., Prosser, WA, 99350
4 - University of Wisconsin - Madison, Horticulture, 1575 Linden Drive, Madison, WI, 54501, United States
5 - The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD, 20850, US
Keywords:
Disease resistance
Innate Immunity.
Session: SOL07-7
Location: Ballroom AB/Monona Terrace
Date: Thursday, July 27th, 2006
Time: 5:00 PM
Abstract ID:419 |
