title: GFP technology for the study of biocontrol agents in tritrophic interactions: a case study with Pseudozyma flocculosa.
abstract: GFP technology was applied to the biocontrol agent (BCA) Pseudozyma flocculosa to study its development and interactions at the tritrophic level plant-powdery mildew-BCA. Transformation experiments with GFP led to the production of a strongly fluorescent strain, Act-4, that displayed biocontrol traits typical of P. flocculosa WT. Following inundative applications, growth of P. flocculosa Act-4 was closely and almost exclusively associated with the colonies of the pathogen regardless of the powdery mildew species or the host plant tested. Development of P. flocculosa Act-4 on control leaves alone was extremely limited 24 h after its application and was typical of the epiphytic growth characterizing this type of yeast-like fungus. Based on the strong correlation between the colonization pattern of the different powdery mildew species tested and the presence of P. flocculosa Act-4, as determined by its fluorescence, it seems that growth of the BCA is dependant on the presence of powdery mildews. These results demonstrate that the GFP technology can be used to study plant-pathogen-BCA interactions and fulfill a wide array of purposes ranging from fundamental observations of the biocontrol behavior of a BCA to very applied ones serving some of the requirements for the registration of BCA's such as defining their environmental fate.
authors.affiliation: Département de Phytologie, Centre de Recherche en Horticulture, Pavillon Envirotron, Université Laval, Québec, Canada G1K 7P4.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Neveu
authors.forename: Caroline
authors.initials: C
authors.lastname: Labbé
authors.forename: Richard R
authors.initials: RR
authors.lastname: Bélanger
mesh_terms: D001203:Ascomycota / Q000235:genetics / Q000254:growth & development*; D018553:Cucumis sativus; D004271:DNA, Fungal / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics*; D018551:Solanum lycopersicum; D008856:Microscopy, Fluorescence; D010572:Pest Control, Biological / Q000379:methods*; D010935:Plant Diseases / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D027826:Rosa; D014170:Transformation, Genetic; D014908:Triticum; D014587:Ustilaginales / Q000235:genetics* / Q000254:growth & development*
chemical_list: D004271:DNA, Fungal; D049452:Green Fluorescent Proteins