| Abstract Detail
Conference Wide Couch, Brett, C. [1], May, Georgiana [1]. Dating recombination in a resistance gene family from the Solanaceae. FREQUENT recombination among tandemly arranged resistance gene (R gene) copies is the hallmark of many disease resistance loci in plant genomes and is a major driver of sequence diversity. Recombination among resistance genes is known to generate chimeric sequences conferring novel resistance specificities. However, the potential for diversity comes with risk of disrupting function and loss of resistance. Although recombination can generate new sequence types over short amounts of time, our research shows that some recombinants are maintained through speciation events. Such results suggest that selection must act to retain recombinant and functional resistance genes while recombinant loss of function copies are lost in genomic drift. In this study we have sampled members of the I2 resistance gene family from genomes of six members of the Solanaceae. I2, from Solanum pimpinellifolium, is a nucleotide binding site (NBS) leucine rich repeat (LRR) R-gene that confers resistance to Fusarium oxysporum f. sp. lycopersici. We obtained sequence from the NBS and LRR domains and analyzed the history recombination within this gene family over the time represented by the sampled species. We assessed the timeframe over which sequences and the linkage of NBS and LRR substitutions have been maintained. Resistance genes and associations of substitutions in different regions of the gene that are maintained through speciation events are prime candidates for functional resistance genes maintained by selection and may provide durable resistance that is not rapidly overcome by a pathogen.
Log in to add this item to your schedule
1 - University of Minnesota, Ecology, Evolution, and Behavior, 100 Ecology Building, 1987 Upper Buford Circle, St. Paul, MN, 55108, USA
Keywords:
tobacco
tomato
Potato
R3a
Pepper.
Session: Poster-123
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:272 |
