title: Contribution of salicylic acid glucosyltransferase, OsSGT1, to chemically induced disease resistance in rice plants.
abstract: Systemic acquired resistance (SAR), a natural disease response in plants, can be induced chemically. Salicylic acid (SA) acts as a key endogenous signaling molecule that mediates SAR in dicotyledonous plants. However, the role of SA in monocotyledonous plants has yet to be elucidated. In this study, the mode of action of the agrochemical protectant chemical probenazole was assessed by microarray-based determination of gene expression. Cloning and characterization of the most highly activated probenazole-responsive gene revealed that it encodes UDP-glucose:SA glucosyltransferase (OsSGT1), which catalyzes the conversion of free SA into SA O-beta-glucoside (SAG). We found that SAG accumulated in rice leaf tissue following treatment with probenazole or 2,6-dichloroisonicotinic acid. A putative OsSGT1 gene from the rice cultivar Akitakomachi was cloned and the gene product expressed in Escherichia coli was characterized, and the results suggested that probenazole-responsive OsSGT1 is involved in the production of SAG. Furthermore, RNAi-mediated silencing of the OsSGT1 gene significantly reduced the probenazole-dependent development of resistance against blast disease, further supporting the suggestion that OsSGT1 is a key mediator of development of chemically induced disease resistance. The OsSGT1 gene may contribute to the SA signaling mechanism by inducing up-regulation of SAG in rice plants.
authors.affiliation: Agricultural & Veterinary Research Laboratories, Meiji Seika Kaisha Ltd, Yokohama 222-8567, Japan. kenji_umemura@meiji.co.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Umemura
authors.forename: Junji
authors.initials: J
authors.lastname: Satou
authors.forename: Michiaki
authors.initials: M
authors.lastname: Iwata
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Uozumi
authors.forename: Jinichiro
authors.initials: J
authors.lastname: Koga
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawano
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Koshiba
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Anzai
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mitomi
mesh_terms: D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005960:Glucosides / Q000378:metabolism*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D012459:Salicylates / Q000378:metabolism*; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D005960:Glucosides; D010940:Plant Proteins; D018749:RNA, Plant; D012459:Salicylates; D013844:Thiazoles; C084746:salicylic acid glucoside; C099063:oryzemate; D005964:Glucosyltransferases; C403140:UDP-glucose - salicylic acid glucosyltransferase