ARS | Publication request: Isolation of Candidate Disease Resistance Gene Families in Soybean

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 1996
Publication Date: N/A

Technical Abstract: In this study, degenerate oligonucleotide primers designed from conserved sequences in the coding regions of the N (tobacco), RPS2 (Arabidopsis) and L6 (flax) disease resistance genes were used to amplify related sequences from soybean (Glycine max (L.) Merr.). Sequencing of amplification products indicated that at least nine families of resistance gene analogs (RGAs) were detected. Genetic mapping of members of these families located them to eight different linkage groups. Several RGA loci mapped near known resistance genes including a cluster of family 1 RGAs which mapped around the Rj2 (ineffective nodulation), Rmd (powdery mildew resistance) and Rps2 (Phytophthora sojae resistance) disease loci on linkage group J. Primers and probes specific for the nine RGA families were used to screen a bacterial artificial (BAC) library and clones representing 5 of the families were identified. Analysis of the BACs based on restriction enzyme digests indicated that individual BACs contained two to six members of a single RGA family. Clustering and sequence similarity of members of RGA families suggests a common process in their evolution. Our data indicate that it may be possible to use sequence homologies from conserved motifs on cloned resistance genes to identify candidate resistance loci in diverse plant taxa.