title: Apoptosis-related genes confer resistance to Fusarium wilt in transgenic 'Lady Finger' bananas.
abstract: Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases of banana (Musa spp.). Apart from resistant cultivars, there are no effective control measures for the disease. We investigated whether the transgenic expression of apoptosis-inhibition-related genes in banana could be used to confer disease resistance. Embryogenic cell suspensions of the banana cultivar, 'Lady Finger', were stably transformed with animal genes that negatively regulate apoptosis, namely Bcl-xL, Ced-9 and Bcl-2 3' UTR, and independently transformed plant lines were regenerated for testing. Following a 12-week exposure to Foc race 1 in small-plant glasshouse bioassays, seven transgenic lines (2 × Bcl-xL, 3 × Ced-9 and 2 × Bcl-2 3' UTR) showed significantly less internal and external disease symptoms than the wild-type susceptible 'Lady Finger' banana plants used as positive controls. Of these, one Bcl-2 3' UTR line showed resistance that was equivalent to that of wild-type Cavendish bananas that were included as resistant negative controls. Further, the resistance of this line continued for 23-week postinoculation at which time the experiment was terminated. Using TUNEL assays, Foc race 1 was shown to induce apoptosis-like features in the roots of wild-type 'Lady Finger' plants consistent with a necrotrophic phase in the life cycle of this pathogen. This was further supported by the observed reduction in these effects in the roots of the resistant Bcl-2 3' UTR-transgenic line. This is the first report on the generation of transgenic banana plants with resistance to Fusarium wilt.
authors.affiliation: Centre for Tropical Crops and Biocommodities, Faculty of Science and Technology, Queensland University of Technology, Brisbane, Qld, Australia.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Paul
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Becker
authors.forename: Martin B
authors.initials: MB
authors.lastname: Dickman
authors.forename: Robert M
authors.initials: RM
authors.lastname: Harding
authors.forename: Harjeet K
authors.initials: HK
authors.lastname: Khanna
authors.forename: James L
authors.initials: JL
authors.lastname: Dale
mesh_terms: D018929:Cell Culture Techniques; D060467:Disease Resistance; D005670:Fusarium / Q000472:pathogenicity*; D018506:Gene Expression Regulation, Plant; D020287:In Situ Nick-End Labeling; D028521:Musa / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018517:Plant Roots / Q000276:immunology / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D011401:Promoter Regions, Genetic; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000276:immunology; D014170:Transformation, Genetic; D003313:Zea mays / Q000235:genetics
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2