title: Relationship between disease resistance and rice oxalate oxidases in transgenic rice.
abstract: Differential expression of rice oxalate oxidase genes (OsOxO1-4) in rice leaves (Oryza sativa L.) in response to biotic stress was assayed using RT-PCR. OsOxO4 was induced transiently at 12 h in plants inoculated with the pathogens of bacterial blight and that of the wounding control. Inoculation with the rice blast pathogen induced OsOxO2 expression compared to the mock spray control. Overexpressing OsOxO1 or OsOxO4 in rice resulted in elevated transcript levels of the respective transgene as well as OsOxO3 in leaves compared to that in untransformed wild type (WT). In a line of RNA-i transgenic rice plants (i-12), expression of all four OsOxO genes except that of OsOxO2 was severely inhibited. Oxalate oxidase (OxO, EC 1.2.3.4) activity in plants overexpressing OsOxO1 or OsOxO4 was substantially higher than that in WT and the RNA-i lines. It was found that transgenic rice plants with substantially higher OxO activity were not more resistant to rice blast and bacterial blight than WT. In contrast, some RNA-i lines with less OxO activity seemed to be more resistant to rice blast while some overexpressing lines were more susceptible to rice blast than WT. Therefore, OxO might not be a disease resistance factor in rice.
authors.affiliation: College of Life Science, South China Agricultural University, Guangzhou, China.
authors.forename: Xian Yong
authors.initials: XY
authors.lastname: Zhang
authors.forename: Zhuan Hua
authors.initials: ZH
authors.lastname: Nie
authors.forename: Wen Juan
authors.initials: WJ
authors.lastname: Wang
authors.forename: David W M
authors.initials: DW
authors.lastname: Leung
authors.forename: Da Gao
authors.initials: DG
authors.lastname: Xu
authors.forename: Bai Ling
authors.initials: BL
authors.lastname: Chen
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chen
authors.forename: Lie Xian
authors.initials: LX
authors.lastname: Zeng
authors.forename: E E
authors.initials: EE
authors.lastname: Liu
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics*; D019076:Transgenes / Q000235:genetics
chemical_list: D010940:Plant Proteins; D010088:Oxidoreductases; C020598:oxalate oxidase