title: Development of disease-resistant rice by pathogen-responsive expression of WRKY45.
abstract: WRKY45 is an important transcription factor in the salicylic acid signalling pathway in rice that mediates chemical-induced resistance against multiple pathogens. Its constitutive overexpression confers extremely strong resistance against Magnaporthe oryzae and Xanthomonas oryzae pv. oryzae to rice, but has adverse effects on agronomic traits. Here, a new strategy to confer rice with strong disease resistance without any negative effects on agronomic traits was established by expressing WRKY45 under the control of pathogen-responsive promoters in combination with a translational enhancer derived from a 5'-untranslated region (UTR) of rice alcohol dehydrogenase (ADH). Rice promoters that responded to M. oryzae and X. oryzae pv. oryzae infections within 24 h were identified, and 2-kb upstream sequences from nine of them were isolated, fused to WRKY45 cDNA with or without the ADH 5'-UTR, and introduced into rice. Although pathogen-responsive promoters alone failed to confer effective disease resistance, the use of the ADH 5'-UTR in combination with them, in particular the PR1b and GST promoters, enhanced disease resistance. Field trials showed that overall, PR1b promoter-driven (with ADH 5'-UTR) lines performed the best and one had agronomic traits comparable to control untransformed rice. Thus, expressing WRKY45 under the control of the PR1b promoter with the ADH 5'-UTR is an excellent strategy to develop disease-resistant rice, and the line established could serve as a mother line for breeding disease-resistant rice.
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Goto
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Fuyuko
authors.initials: F
authors.lastname: Sasakura-Shimoda
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Muneo
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Nagao
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.|Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Suetsugu
authors.affiliation: Plant-Microbe Interaction Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ochiai
authors.affiliation: Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.|Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takatsuji
mesh_terms: D020121:5' Untranslated Regions; D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics; D020082:Magnaporthe / Q000472:pathogenicity; D012275:Oryza / Q000235:genetics* / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000382:microbiology*; D014974:Xanthomonas / Q000472:pathogenicity
chemical_list: D020121:5' Untranslated Regions; D010940:Plant Proteins; D000426:Alcohol Dehydrogenase
keywords: Magnaporthe oryzae; Oryza sativa; Xanthomonas oryzae; plant activator; salicylic acid; transcription factor