Originally published as Genetics Published Articles Ahead of Print on October 20, 2008.

Genetics, Vol. 180, 2267-2276, December 2008, Copyright © 2008
doi:10.1534/genetics.108.095034

Two Adjacent Nucleotide-Binding Site–Leucine-Rich Repeat Class Genes Are Required to Confer Pikm-Specific Rice Blast Resistance

Ikuo Ashikawa^*,1, Nagao Hayashi, Hiroko Yamane, Hiroyuki Kanamori, Jianzhong Wu, Takashi Matsumoto, Kazuko Ono^** and Masahiro Yano^**

^* NARO, National Institute of Crop Science, Tsukuba, Ibaraki 305-8518, Japan, Plant Disease Resistance Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan, Institute of the Society for Techno-Innovation of Agriculture, Forestry, and Fisheries, Tsukuba, Ibaraki 305-0854, Japan, Plant Genome Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan and ^** QTL Genomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan

¹ Corresponding author: NARO, National Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan.
E-mail: ashikawa{at}affrc.go.jp

The rice blast resistance gene Pikm was cloned by a map-based cloning strategy. High-resolution genetic mapping and sequencing of the gene region in the Pikm-containing cultivar Tsuyuake narrowed down the candidate region to a 131-kb genomic interval. Sequence analysis predicted two adjacently arranged resistance-like genes, Pikm1-TS and Pikm2-TS, within this candidate region. These genes encoded proteins with a nucleotide-binding site (NBS) and leucine-rich repeats (LRRs) and were considered the most probable candidates for Pikm. However, genetic complementation analysis of transgenic lines individually carrying these two genes negated the possibility that either Pikm1-TS or Pikm2-TS alone was Pikm. Instead, it was revealed that transgenic lines carrying both of these genes expressed blast resistance. The results of the complementation analysis and an evaluation of the resistance specificity of the transgenic lines to blast isolates demonstrated that Pikm-specific resistance is conferred by cooperation of Pikm1-TS and Pikm2-TS. Although these two genes are not homologous with each other, they both contain all the conserved motifs necessary for an NBS–LRR class gene to function independently as a resistance gene.

This article has been cited by other articles:

				S. Lee, S. Costanzo, Y. Jia, K. M. Olsen, and A. L. Caicedo Evolutionary Dynamics of the Genomic Region Around the Blast Resistance Gene Pi-ta in AA Genome Oryza Species Genetics, December 1, 2009; 183(4): 1315 - 1325. [Abstract] [Full Text] [PDF]

				J. Shang, Y. Tao, X. Chen, Y. Zou, C. Lei, J. Wang, X. Li, X. Zhao, M. Zhang, Z. Lu, et al. Identification of a New Rice Blast Resistance Gene, Pid3, by Genomewide Comparison of Paired Nucleotide-Binding Site-Leucine-Rich Repeat Genes and Their Pseudogene Alleles Between the Two Sequenced Rice Genomes Genetics, August 1, 2009; 182(4): 1303 - 1311. [Abstract] [Full Text] [PDF]

				K. Yoshida, H. Saitoh, S. Fujisawa, H. Kanzaki, H. Matsumura, K. Yoshida, Y. Tosa, I. Chuma, Y. Takano, J. Win, et al. Association Genetics Reveals Three Novel Avirulence Genes from the Rice Blast Fungal Pathogen Magnaporthe oryzae PLANT CELL, May 1, 2009; 21(5): 1573 - 1591. [Abstract] [Full Text] [PDF]

				S.-K. Lee, M.-Y. Song, Y.-S. Seo, H.-K. Kim, S. Ko, P.-J. Cao, J.-P. Suh, G. Yi, J.-H. Roh, S. Lee, et al. Rice Pi5-Mediated Resistance to Magnaporthe oryzae Requires the Presence of Two Coiled-Coil-Nucleotide-Binding-Leucine-Rich Repeat Genes Genetics, April 1, 2009; 181(4): 1627 - 1638. [Abstract] [Full Text] [PDF]

International Access Link

Online ISSN: 1943-2361  Print ISSN: 0016-6731
Copyright 2009 by the Genetics Society of America
phone: 412-268-1812   fax: 412-268-1813   email: genetics-gsa{at}andrew.cmu.edu