Arabidopsis thaliana: a source of candidate disease-resistance genes for Brassica napus

Sillito, D.; Parkin, I.A.P.; Mayerhofer, R.; Lydiate, D.J.; Good, A.G.

Arabidopsis thaliana: a source of candidate disease-resistance genes for Brassica napus

2000

Sillito, D. | Parkin, I.A.P. | Mayerhofer, R. | Lydiate, D.J. | Good, A.G.

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.

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