title: Ten rice peroxidases redundantly respond to multiple stresses including infection with rice blast fungus.
abstract: Class III plant peroxidases are believed to function in diverse physiological processes including disease resistance and wound response, but predicted low substrate specificities and the presence of 70 or more isoforms have made it difficult to define a specific physiological function(s) for each gene. To select pathogen-responsive POX genes, we analyzed the expression profiles of 22 rice POX genes after infection with rice blast fungus. The expression of 10 POX genes among the 22 genes was induced after fungal inoculation in both compatible and incompatible hosts. Seven of the 10 POX genes were expressed at higher levels in the incompatible host than in the compatible host 6-24 h after inoculation by which time no fungus-induced lesions have appeared. Organ-specific expression and stress-induced expression by wounding and treatment with probenazole, an agrichemical against blast fungus, jasmonic acid, salicylic acid and 1-aminocyclopropane-1-carboxylate, a precursor of ethylene, indicated that rice POXs have individual characteristics and can be classified into several types. A comparison of the amino acid sequences of POXs showed that multiple isoforms with a high sequence similarity respond to stress in different or similar ways. Such redundant responses of POX genes may guarantee POX activities that are necessary for self-defense in plant tissues against environmental stresses including pathogen infection.
authors.affiliation: Department of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan.
authors.forename: Katsutomo
authors.initials: K
authors.lastname: Sasaki
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Iwai
authors.forename: Susumu
authors.initials: S
authors.lastname: Hiraga
authors.forename: Katsushi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Shigemi
authors.initials: S
authors.lastname: Seo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Mitsuhara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyasaka
authors.forename: Masataka
authors.initials: M
authors.lastname: Iwano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Matsui
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ohashi
mesh_terms: D000598:Amino Acids, Cyclic / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics / Q000502:physiology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D020082:Magnaporthe / Q000472:pathogenicity*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D054883:Oxylipins; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011930:Reaction Time / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation / Q000235:genetics
chemical_list: D000598:Amino Acids, Cyclic; D000935:Antifungal Agents; D003517:Cyclopentanes; D007527:Isoenzymes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C023863:1-aminocyclopropane-1-carboxylic acid; C011006:jasmonic acid; D010544:Peroxidases