title: Expression of an oxalate decarboxylase impairs the necrotic effect induced by Nep1-like protein (NLP) of Moniliophthora perniciosa in transgenic tobacco.
abstract: Oxalic acid (OA) and Nep1-like proteins (NLP) are recognized as elicitors of programmed cell death (PCD) in plants, which is crucial for the pathogenic success of necrotrophic plant pathogens and involves reactive oxygen species (ROS). To determine the importance of oxalate as a source of ROS for OA- and NLP-induced cell death, a full-length cDNA coding for an oxalate decarboxylase (FvOXDC) from the basidiomycete Flammulina velutipes, which converts OA into CO(2) and formate, was overexpressed in tobacco plants. The transgenic plants contained less OA and more formic acid compared with the control plants and showed enhanced resistance to cell death induced by exogenous OA and MpNEP2, an NLP of the hemibiotrophic fungus Moniliophthora perniciosa. This resistance was correlated with the inhibition of ROS formation in the transgenic plants inoculated with OA, MpNEP2, or a combination of both PCD elicitors. Taken together, these results have established a pivotal function for oxalate as a source of ROS required for the PCD-inducing activity of OA and NLP. The results also indicate that FvOXDC represents a potentially novel source of resistance against OA- and NLP-producing pathogens such as M. perniciosa, the causal agent of witches' broom disease of cacao (Theobroma cacao L.).
authors.affiliation: Centro de Biotecnologia e Genetica, Universidade Estadual de Santa Cruz, Brazil.
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: da Silva
authors.forename: Cristiano V
authors.initials: CV
authors.lastname: Dias
authors.forename: Luciana C
authors.initials: LC
authors.lastname: Cidade
authors.forename: Juliano S
authors.initials: JS
authors.lastname: Mendes
authors.forename: Carlos P
authors.initials: CP
authors.lastname: Pirovani
authors.forename: Fátima C
authors.initials: FC
authors.lastname: Alvim
authors.forename: Gonçalo A G
authors.initials: GA
authors.lastname: Pereira
authors.forename: Francisco J L
authors.initials: FJ
authors.lastname: Aragão
authors.forename: Júlio C M
authors.initials: JC
authors.lastname: Cascardo
authors.forename: Marcio G C
authors.initials: MG
authors.lastname: Costa
mesh_terms: D000363:Agaricales / Q000378:metabolism* / Q000472:pathogenicity*; D002262:Carboxy-Lyases / Q000096:biosynthesis* / Q000235:genetics; D016923:Cell Death; D055393:Flammulina / Q000201:enzymology / Q000235:genetics; D005561:Formates / Q000378:metabolism; D009336:Necrosis; D019815:Oxalic Acid / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D030821:Plants, Genetically Modified; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000382:microbiology
chemical_list: D005561:Formates; D017382:Reactive Oxygen Species; C030544:formic acid; D019815:Oxalic Acid; D002262:Carboxy-Lyases; C021915:oxalate decarboxylase