title: OsWRKY22, a monocot WRKY gene, plays a role in the resistance response to blast.
abstract: With the aim of identifying novel regulators of host and nonhost resistance to fungi in rice, we carried out a systematic mutant screen of mutagenized lines. Two mutant wrky22 knockout lines revealed clear-cut enhanced susceptibility to both virulent and avirulent Magnaporthe oryzae strains and altered cellular responses to nonhost Magnaporthe grisea and Blumeria graminis fungi. In addition, the analysis of the pathogen responses of 24 overexpressor OsWRKY22 lines revealed enhanced resistance phenotypes on infection with virulent M. oryzae strain, confirming that OsWRKY22 is involved in rice resistance to blast. Bioinformatic analyses determined that the OsWRKY22 gene belongs to a well-defined cluster of monocot-specific WRKYs. The co-regulatory analysis revealed no significant co-regulation of OsWRKY22 with a representative panel of OsWRKYs, supporting its unique role in a series of transcriptional responses. In contrast, inquiring a subset of biotic stress-related Affymetrix data, a large number of resistance and defence-related genes were found to be putatively co-expressed with OsWRKY22. Taken together, all gathered experimental evidence places the monocot-specific OsWRKY22 gene at the convergence point of signal transduction circuits in response to both host and nonhost fungi encountering rice plants.
authors.affiliation: Rice Genomics Unit, Parco Tecnologico Padano, via Einstein, 26900 Lodi, Italy. pamela.abbruscato@tecnoparco.org
authors.forename: Pamela
authors.initials: P
authors.lastname: Abbruscato
authors.forename: Tamás
authors.initials: T
authors.lastname: Nepusz
authors.forename: Luca
authors.initials: L
authors.lastname: Mizzi
authors.forename: Marcello
authors.initials: M
authors.lastname: Del Corvo
authors.forename: Piero
authors.initials: P
authors.lastname: Morandini
authors.forename: Irene
authors.initials: I
authors.lastname: Fumasoni
authors.forename: Corinne
authors.initials: C
authors.lastname: Michel
authors.forename: Alberto
authors.initials: A
authors.lastname: Paccanaro
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guiderdoni
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schaffrath
authors.forename: Jean-Benoît
authors.initials: JB
authors.lastname: Morel
authors.forename: Pietro
authors.initials: P
authors.lastname: Piffanelli
authors.forename: Odile
authors.initials: O
authors.lastname: Faivre-Rampant
mesh_terms: D019295:Computational Biology; D017343:Genes, Plant; D020082:Magnaporthe / Q000472:pathogenicity*; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D014774:Virulence