Cloning and molecular characterization of three members of the NBS-LRR subfamily located in the vicinity of the Co-2 locus for anthracnose resistance in Phaseolus vulgaris

Genome. 1999 Apr;42(2):254-64. doi: 10.1139/g98-134.

Abstract

Co-2 is one of the R-genes against anthracnose identified in common bean. A RAPD marker, cloned as PvH20, was previously shown to contain 6 imperfect leucine-rich-repeats and to reveal a family of related sequences in the vicinity of the Co-2 locus. Using PvH20 as probe, a genomic clone and 2 partial cDNAs were isolated. DNA sequencing revealed that the 6.1 kb genomic fragment contains sequences encoding both NBS-LRR (ORF1) and kinase-like (ORF2) products. The 2 partial cDNAs (cD7 and cD8) belong to the NBS-LRR subfamily as do most of the resistance genes cloned to date. The LRR domain of ORF1 is interrupted by 2 stop codons suggesting that it corresponds to a non-functional member of the multigene family and ORF2 appears to be a kinase pseudogene. The 3 NBS-LRR polypeptides share a high level of amino acid identity and represent different members of a related family. By genetic mapping ORF1, cD7, and cD8 were found to span a genetic distance of 3 cM: cD8 maps at 2 cM from Co-2 and 3 cM from ORF1, cD7 maps at 1 cM from ORF1 and co-segregates with Co-2, thus cD7 might be a putative candidate for the Co-2 R-gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA, Plant
  • Fabaceae / genetics*
  • Genes, Plant
  • Molecular Sequence Data
  • Multigene Family
  • Open Reading Frames
  • Plants, Medicinal*
  • Proteins / genetics*

Substances

  • DNA, Plant
  • Proteins
  • leucine-rich repeat proteins

Associated data

  • GENBANK/AF098970
  • GENBANK/AF098971