Rice Pi5-mediated resistance to Magnaporthe oryzae requires the presence of two coiled-coil-nucleotide-binding-leucine-rich repeat genes.
Rice blast, caused by the fungus Magnaporthe oryzae, is one of the most devastating diseases of rice. To understand the molecular basis of Pi5-mediated resistance to M. oryzae, we cloned the resistance (R) gene at this locus using a map-based cloning strategy. Genetic and phenotypic analyses of 2014 F2 progeny from a mapping population derived from a cross between IR50, a susceptible rice cultivar, and the RIL260 line carrying Pi5 enabled us to narrow down the Pi5 locus to a 130-kb interval. Sequence analysis of this genomic region identified two candidate genes, Pi5-1 and Pi5-2, which encode proteins carrying three motifs characteristic of R genes: an N-terminal coiled-coil (CC) motif, a nucleotide-binding (NB) domain, and a leucine-rich repeat (LRR) motif. In genetic transformation experiments of a susceptible rice cultivar, neither the Pi5-1 nor the Pi5-2 gene was found to confer resistance to M. oryzae. In contrast, transgenic rice plants expressing both of these genes, generated by crossing transgenic lines carrying each gene individually, conferred Pi5-mediated resistance to M. oryzae. Gene expression analysis revealed that Pi5-1 transcripts accumulate after pathogen challenge, whereas the Pi5-2 gene is constitutively expressed. These results indicate that the presence of these two genes is required for rice Pi5-mediated resistance to M. oryzae.
Lee
Sang-Kyu
SK
Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, Korea.
Song
Min-Young
MY
Seo
Young-Su
YS
Kim
Hye-Kyung
HK
Ko
Seho
S
Cao
Pei-Jian
PJ
Suh
Jung-Pil
JP
Yi
Gihwan
G
Roh
Jae-Hwan
JH
Lee
Sichul
S
An
Gynheung
G
Hahn
Tae-Ryong
TR
Wang
Guo-Liang
GL
Ronald
Pamela
P
Jeon
Jong-Seong
JS
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology; D007113:Immunity, Innate / Q000235:genetics*; D016350:Leucine Zippers / Q000235:genetics; D020082:Magnaporthe / Q000276:immunology* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D015843:Serpins / Q000235:genetics / Q000502:physiology*
D004268:DNA-Binding Proteins; D010940:Plant Proteins; C085344:SERPIN-B5; D015843:Serpins