title: Transposon tagging of tobacco mosaic virus resistance gene N: its possible role in the TMV-N-mediated signal transduction pathway.
abstract: Plants can recognize and resist invading pathogens by signaling the induction of rapid defense responses. Often these responses are mediated by single dominant resistance genes (R genes). The products of R genes have been postulated to recognize the pathogen and trigger rapid host defense responses. Here we describe isolation of the classical resistance gene N of tobacco that mediates resistance to the well-characterized pathogen tobacco mosaic virus (TMV). The N gene was isolated by transposon tagging using the maize Activator (Ac) transposon. We confirmed isolation of the N gene by complementation of the TMV-sensitive phenotype with a genomic DNA fragment. Sequence analysis of the N gene shows that it encodes a protein with an amino-terminal domain similar to that of the cytoplasmic domains of the Drosophila Toll protein and the interleukin 1 receptor in mammals, a putative nucleotide-binding site and 14 imperfect leucine-rich repeats. The presence of these functional domains in the predicted N gene product is consistent with the hypothesis that the N resistance gene functions in a signal transduction pathway. Similarities of N to Toll and the interleukin 1 receptor suggest a similar signaling mechanism leading to rapid gene induction and TMV resistance.
authors.affiliation: Department of Plant Biology, University of California, Berkeley 94720, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Dinesh-Kumar
authors.forename: S
authors.initials: S
authors.lastname: Whitham
authors.forename: D
authors.initials: D
authors.lastname: Choi
authors.forename: R
authors.initials: R
authors.lastname: Hehl
authors.forename: C
authors.initials: C
authors.lastname: Corr
authors.forename: B
authors.initials: B
authors.lastname: Baker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics; D017343:Genes, Plant; D007113:Immunity, Innate / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010641:Phenotype; D010947:Plants, Toxic; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics* / Q000821:virology*; D014027:Tobacco Mosaic Virus / Q000235:genetics / Q000472:pathogenicity*; D003313:Zea mays / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements