title: Expressing a gene encoding wheat oxalate oxidase enhances resistance to Sclerotinia sclerotiorum in oilseed rape (Brassica napus).
abstract: Sclerotinia sclerotiorum causes a highly destructive disease in oilseed rape (Brassica napus). Oxalic acid (OA) secreted by the pathogen is a key pathogenicity factor. Oxalate oxidase (OXO) can oxidize OA into CO2 and H2O2. In this study, we show that transgenic oilseed rape (sixth generation lines) constitutively expressing wheat (Triticum aestivum) OXO displays considerably increased OXO activity and enhanced resistance to S. sclerotiorum (with up to 90.2 and 88.4% disease reductions compared with the untransformed parent line and a resistant control, respectively). Upon application of exogenous OA, the pH values in transgenic plants were maintained at levels slightly lower than 5.58 measured prior to OA treatment, whereas the pH values in untransformed plants decreased rapidly and were markedly lower than 5.63 measured prior to OA treatment. Following pathogen inoculation, H2O2 levels were higher in transgenic plants than in untransformed plants. These results indicate that the enhanced resistance of the OXO transgenic oilseed rape to Sclerotinia is probably mediated by OA detoxification. We believe that enhancing the OA metabolism of oilseed rape in this way will be an effective strategy for improving resistance to S. sclerotiorum.
authors.affiliation: The Key Laboratory of Genetic Improvement for Oil Crops, The Ministry of Agriculture, Wuhan, People's Republic of China.
authors.forename: Xiangbai
authors.initials: X
authors.lastname: Dong
authors.forename: Ruiqin
authors.initials: R
authors.lastname: Ji
authors.forename: Xuelan
authors.initials: X
authors.lastname: Guo
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Foster
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Caihua
authors.initials: C
authors.lastname: Dong
authors.forename: Yueying
authors.initials: Y
authors.lastname: Liu
authors.forename: Qiong
authors.initials: Q
authors.lastname: Hu
authors.forename: Shengyi
authors.initials: S
authors.lastname: Liu
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D029688:Brassica napus / Q000382:microbiology / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D007113:Immunity, Innate; D019815:Oxalic Acid / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases; D018515:Plant Leaves / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000382:microbiology / Q000502:physiology; D014908:Triticum / Q000235:genetics*
chemical_list: D019815:Oxalic Acid; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C020598:oxalate oxidase