title: An exo-1,3-β-glucanase GLU1 contributes to the virulence of the wheat tan spot pathogen Pyrenophora tritici-repentis.
abstract: Tan spot, caused by Pyrenophora tritici-repentis, is an important foliar disease of wheat. In the present study, a gene named glucanase gene (GLU1) encoding a putative exo-1,3-β-glucanase was cloned from a race five isolate of P. tritici-repentis. Transcription profile analysis of the GLU1 gene showed a carbon source control of the accumulation of transcript, which is strongly induced in minimal medium but depressed in rich medium. A time-course study of the infection process of the wild-type isolate on a susceptible wheat genotype revealed that the transcript level of GLU1 increased more than 8000-fold 8 h after inoculation. To study its potential function in pathogenicity, GLU1 was silenced via a sense and antisense mediated silencing mechanism. One transformant named C1 showed significantly reduced growth and sporulation relative to the wild-type. Cytological analysis of the infection revealed that C1 produced significantly lower numbers of germ tubes and appressoria than the wild-type strain on susceptible wheat leaves. This strain, as well as another two transformants, caused significantly less disease symptoms relative to the wild-type after inoculation onto a susceptible wheat genotype. These results indicate that GLU1 contributes to the development and virulence of P. tritici-repentis.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada.
authors.forename: Heting
authors.initials: H
authors.lastname: Fu
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.forename: Reem
authors.initials: R
authors.lastname: Aboukhaddour
authors.forename: Tiesen
authors.initials: T
authors.lastname: Cao
authors.forename: Sheau-Fang
authors.initials: SF
authors.lastname: Hwang
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Strelkov
mesh_terms: D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D002244:Carbon / Q000378:metabolism; D003001:Cloning, Molecular; D003470:Culture Media / Q000737:chemistry; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D043326:Glucan 1,3-beta-Glucosidase / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D014908:Triticum / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D003470:Culture Media; D037521:Virulence Factors; D002244:Carbon; D043326:Glucan 1,3-beta-Glucosidase
keywords: Cell wall degrading enzymes (CWDE); Disease development; Gene knockdown; Gene silencing; Pathogenicity