Kim, Sang-Hee , Saha, Dipanwita , Anyanwu, Nkemdi , Kwon, Soon Il , Gassmann, Walter .
The Arabidopsis RPS6 disease resistance gene encodes a member of the TIR-NBS-LRR class of proteins.
Plant immune responses are determined in part by specific interactions between a host resistance (R) gene and a pathogen avirulence (avr) gene. hopPsyA from Pseudomonas syringae pv. syringae strain 61 was identified as a novel avr gene for Arabidopsis, but the corresponding R gene had not been identified. Mutations in the EDS1 (ENHANCED DISEASE SUSCEPTIBILITY1) gene abolish resistance dependent on Toll/Interleukin-1 receptor (TIR) nucleotide-binding site (NBS) leucine-rich repeat (LRR) class R genes. Interestingly, hopPsyA signaling was EDS1-dependent, suggesting that the hopPsyA R gene belongs to the TIR-NBS-LRR class of R genes. We screened approximately 20,000 EMS-mutagenized RLD plants, an accession resistant to hopPsyA, and isolated 4 hopPsyA susceptible (hps) mutants. Of these four mutants, two were placed in the hps1 complementation group. Here, we report the positional cloning of HPS1. HPS1 encodes a member of the TIR-NBS-LRR class of R genes. According to the nomenclature convention for R genes, HPS1 was renamed RPS6 (Resistance to P. syringae). The rps6-1 allele had a point mutation that changes His to Arg within the highly conserved MetHisAsp motif in the NBS domain. Gly was changed to Asp within the kinase I motif of the NBS domain in the rps6-2 allele. RT-PCR results suggest the presence of unspliced RPS6 messenger variants. To date RPS4 and RPS6 are the only Arabidopsis TIR-NBS-LRR R genes for which avr genes are known. Both are EDS1- dependent. RPS6 will allow a direct comparison with RPS4 to dissect the EDS1-dependent signaling pathway.
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1 - University of Missouri-Columbia, Division of Plant science, 314 Life science center, University of Missouri-columbia, Columbia, Mo, 65211, USA
2 - University of Missouri-Columbia, Division of Plant science
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM