Isolation and Analysis of NBS-LRR Resistance Gene Analogs from Sesame

Cloning and analysis of resistance gene analogs(RGAs)of resistant/susceptible sesame to Macrophomina phaseoli could lay the foundation for cloning resistance-related genes.One pair of degenerate primers and two pairs of specific primers were designed based on nucleotide binding site(NBS)-leucine rich repeats(LRR) conserved domain of reported resistance genes from other plants to amplify resistance genes from six sesame varieties resistant to Macrphomina phaseoli and eleven RGAs were obtained.BLAST X analysis indicated that eleven RGAs showed high sequence identities with the known RGAs,and the amino acid identities were 42%-57%.Clustering analysis showed that the eleven RGAs were sorted into five subgroups and all belonged to non-TIR-NBS-LRR type of resistance genes.Putative amino acid sequences all had characteristic sequences of NBS conserved domain to some extent,and shared 18.2%-49.7% identities with known resistance genes in P-loop-GLPL region.