Cloning and Characterization of Nbs-Lrr Class Resistance-Gene Analogs Sequences in Sunflower

A number of disease resistance gene-like DNA sequences were cloned from wild species of sunflower (Helianthus argofillus), using a PCR approach with degenerate primers designed from conserved NBS (nucleotide-binding site) motifs found in a number of plant resistance genes. After sequencing of cloned fragment, the similarity to the known resistance genes was found (NBS2, NBS5 - NBS-LRR class resistance-gene analogs in sunflower (Helianthus annuus), RLG5, c27 - resistance-gene homologues in soybean (Glycine max), FRGA-A5 - NBS-LRR resistance-gene analog in apple-tree (Malus domestica). These results indicate that resistance-gene analogs sequences amplified with the NBS-derived degenerate primers are valuable sources for developing markers in disease resistance-gene tagging, mapping and cloning