Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1998-8-20
pubmed:databankReference
pubmed:abstractText
The recent cloning of genes for resistance against diverse pathogens from a variety of plants has revealed that many share conserved sequence motifs. This provides the possibility of isolating numerous additional resistance genes by polymerase chain reaction (PCR) with degenerate oligonucleotide primers. We amplified resistance gene candidates (RGCs) from lettuce with multiple combinations of primers with low degeneracy designed from motifs in the nucleotide binding sites (NBSs) of RPS2 of Arabidopsis thaliana and N of tobacco. Genomic DNA, cDNA, and bacterial artificial chromosome (BAC) clones were successfully used as templates. Four families of sequences were identified that had the same similarity to each other as to resistance genes from other species. The relationship of the amplified products to resistance genes was evaluated by several sequence and genetic criteria. The amplified products contained open reading frames with additional sequences characteristic of NBSs. Hybridization of RGCs to genomic DNA and to BAC clones revealed large numbers of related sequences. Genetic analysis demonstrated the existence of clustered multigene families for each of the four RGC sequences. This parallels classical genetic data on clustering of disease resistance genes. Two of the four families mapped to known clusters of resistance genes; these two families were therefore studied in greater detail. Additional evidence that these RGCs could be resistance genes was gained by the identification of leucine-rich repeat (LRR) regions in sequences adjoining the NBS similar to those in RPM1 and RPS2 of A. thaliana. Fluorescent in situ hybridization confirmed the clustered genomic distribution of these sequences. The use of PCR with degenerate oligonucleotide primers is therefore an efficient method to identify numerous RGCs in plants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0894-0282
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
815-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9675895-Amino Acid Sequence, pubmed-meshheading:9675895-Arabidopsis Proteins, pubmed-meshheading:9675895-Binding Sites, pubmed-meshheading:9675895-Chromosome Mapping, pubmed-meshheading:9675895-DNA Primers, pubmed-meshheading:9675895-Gene Dosage, pubmed-meshheading:9675895-Genes, Plant, pubmed-meshheading:9675895-Genome, Plant, pubmed-meshheading:9675895-In Situ Hybridization, Fluorescence, pubmed-meshheading:9675895-Lettuce, pubmed-meshheading:9675895-Molecular Sequence Data, pubmed-meshheading:9675895-Multigene Family, pubmed-meshheading:9675895-Nucleic Acid Hybridization, pubmed-meshheading:9675895-Nucleotides, pubmed-meshheading:9675895-Plant Diseases, pubmed-meshheading:9675895-Plant Proteins, pubmed-meshheading:9675895-Polymerase Chain Reaction, pubmed-meshheading:9675895-Sequence Analysis, DNA, pubmed-meshheading:9675895-Sequence Homology, Amino Acid
pubmed:year
1998
pubmed:articleTitle
Resistance gene candidates identified by PCR with degenerate oligonucleotide primers map to clusters of resistance genes in lettuce.
pubmed:affiliation
Department of Vegetable Crops, University of California, Davis 95616, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.