Proteomic analysis of pathogen-responsive proteins from rice leaves induced by rice blast fungus, Magnaporthe grisea.
Proteomic approaches using two-dimensional gel electrophoresis (2-DE) were adopted to identify proteins from rice leaf that are differentially expressed in response to the rice blast fungus, Magnaporthe grisea. Microscopic observation of inoculated leaf with M. grisea revealed that callose deposition and hypersensitive response was clearly visible in incompatible interactions but excessive invading hypha with branches were evident in compatible interactions. Proteins were extracted from leaves 24, 48, and 72 hours after rice blast fungus inoculation. Eight proteins resolved on the 2-DE gels were induced or increased in the inoculated leaf. Matrix-assisted laser desorption/ionization-time of flight analysis of these differentially displayed proteins showed them to be two receptor-like protein kinases (RLK), two beta-1.3-glucanases (Glu1, Glu2), thaumatin-like protein (TLP), peroxidase (POX 22.3), probenazole-inducible protein (PBZ1), and rice pathogenesis-related 10 (OsPR-10). Of these proteins, RLK, TLP, PBZ, and OsPR-10 proteins were induced more in the incompatible interactions than in compatible ones. A phytohormone, jasmonic acid also induced all eight proteins in leaves. To confirm whether the expression profile is equal to the 2-DE data, seven cDNA clones were used as probes in Northern hybridization experiments using total RNA from leaf tissues inoculated with incompatible and compatible rice blast fungal races. The genes encoding POX22.3, Glu1, Glu2, TLP, OsRLK, PBZ1, and OsPR-10 were activated in inoculated leaves, with TLP, OsRLK, PBZ1, and OsPR-10 being expressed earlier and more in incompatible than in compatible interactions. These results suggest that early and high induction of these genes may provide host plants with leading edges to defend themselves. The localization of two rice PR-10 proteins, PBZ1 and OsPR-10, was further examined by immunohistochemical analysis. PBZ1 accumulated highly in mesophyll cells under the attachment site of the appressorium. In contrast, OsPR-10 expression was mainly localized to vascular tissue.
Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Environmental Biotechnology National Core Research Center, Gyeongsang National University, Chinju, Korea.
Sun Tae
ST
Kim
Sang Gon
SG
Kim
Du Hyeon
DH
Hwang
Sun Young
SY
Kang
Han Ju
HJ
Kim
Byung Hyun
BH
Lee
Jeung Joo
JJ
Lee
Kyu Young
KY
Kang
D015152:Blotting, Northern; D015180:Electrophoresis, Gel, Two-Dimensional; D007150:Immunohistochemistry; D020082:Magnaporthe / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism* / Q000382:microbiology; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism
C099062:PBZ1 protein, Oryza sativa; D010937:Plant Growth Regulators; D010940:Plant Proteins; D020543:Proteome