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The EMBO Journal
(2000) 19, 4004–4014, doi:10.1093/emboj/19.15.4004
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| Direct interaction of resistance gene and avirulence gene products confers rice blast resistance |
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Yulin Jia2, Sean A. McAdams1, Gregory T. Bryan1, Howard P. Hershey1 and Barbara Valent1
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1 DuPont Agricultural Products, PO Box 80402, Wilmington, DE 19880-0402, USA
2 Present address: USDA-ARS, Dale Bumpers National Rice Research Center, Stuttgart, AR, 72160, USA
To whom correspondence should be addressed
Barbara Valent, barbara.s.valent@usa.dupont.com
Received 3 February 2000; Revised 5 June 2000; Accepted 5 June 2000.
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| Abstract |
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| Rice expressing the Pi-ta gene is resistant to strains of the rice blast fungus, Magnaporthe grisea, expressing AVR-Pita in a gene-for-gene relationship. Pi-ta encodes a putative cytoplasmic receptor with a centrally localized nucleotide-binding site and leucine-rich domain (LRD) at the C-terminus. AVR-Pita is predicted to encode a metalloprotease with an N-terminal secretory signal and pro-protein sequences. AVR-Pita176 lacks the secretory and pro-protein sequences. We report here that transient expression of AVR-Pita176 inside plant cells results in a Pi-ta-dependent resistance response. AVR-Pita176 protein is shown to bind specifically to the LRD of the Pi-ta protein, both in the yeast two-hybrid system and in an in vitro binding assay. Single amino acid substitutions in the Pi-ta LRD or in the AVR-Pita176 protease motif that result in loss of resistance in the plant also disrupt the physical interaction, both in yeast and in vitro. These data suggest that the AVR-Pita176 protein binds directly to the Pi-ta LRD region inside the plant cell to initiate a Pi-ta-mediated defense response. |
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| Keywords: ligand, Magnaporthe grisea, receptor, rice, signal recognition |
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