Arabidopsis thaliana: a source of candidate disease-resistance genes for Brassica napus.
Common structural and amino acid motifs among cloned plant disease-resistance genes (R genes), have made it possible to identify putative disease-resistance sequences based on DNA sequence identity. Mapping of such R-gene homologues will identify candidate disease-resistance loci to expedite map-based cloning strategies in complex crop genomes. Arabidopsis thaliana expressed sequence tags (ESTs) with homology to cloned plant R genes (R-ESTs), were mapped in both A. thaliana and Brassica napus to identify candidate R-gene loci and investigate intergenomic collinearity. Brassica R-gene homologous sequences were also mapped in B. napus. In total, 103 R-EST loci and 36 Brassica R-gene homologous loci were positioned on the N-fo-61-9 B. napus genetic map, and 48 R-EST loci positioned on the Columbia x Landsberg A. thaliana map. The mapped loci identified collinear regions between Arabidopsis and Brassica which had been observed in previous comparative mapping studies; the detection of syntenic genomic regions indicated that there was no apparent rapid divergence of the identified genomic regions housing the R-EST loci.
Sillito
D
D
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Parkin
I A
IA
Mayerhofer
R
R
Lydiate
D J
DJ
Good
A G
AG
D017360:Arabidopsis / Q000235:genetics*; D015139:Blotting, Southern; D001937:Brassica / Q000235:genetics*; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000032:analysis; D020224:Expressed Sequence Tags; D010935:Plant Diseases / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012689:Sequence Homology, Nucleic Acid
D018744:DNA, Plant