Periodic Reporting for period 1 - BIO-Banana IN and OUT (BIO: Banana IN and OUT - engineering resistance against Panama disease in banana )
Reporting period: 2016-04-01 to 2018-03-31
Traditional breeding of banana is expensive, time- and space-consuming. The key goals of this project was to create a resistance against Fusarium wilt in banana. To do so, I first established a greenhouse pathogenicity assay using small banana plantlets that allows quick resistance screening even in small greenhouses in temperate countries. We will publish this method open access so that it can replace current, cumbersome pathogenicity testing, which requires bigger plants and therefore lots of greenhouse space. Genetic engineering of existing cultivars is one solution to combat current threats of banana production. Initially, we planned to introduce a resistance gene and inactivate a susceptibility gene for Foc TR4 to create resistance. Neither of these strategies turned out to be perfect. In contrast to the interaction of tomato with F. oxysporum f. sp. lycopersici, the receptor kinase encoding susceptibility gene does not seem to be a susceptibility gene for banana, since the Foc effector peptide RALF that is targeting this receptor kinase is not a strong virulence factor for Foc. Likewise, the tomato resistance protein I-3 seems to requires additional tomato factors and is therefore not suitable for transfer in banana. Since, genetically engineered bananas might have faced difficultires with consumer acceptance and would have been difficult to de-regulate, we decided to change our strategy and to explore biologicals as a means to control Fusarium wilt disease.
Biologicals are antagonistic microbial strains or molecules. They are a promising solution to control Fusarium wilt , expecially for smallholder farmers, because they are inexpensive and offers potentially season-long disease control. We successfully identified a bacterial strain that is able to inhibit Foc growth.
Traditional breeding of banana is expensive, time- and space-consuming. The key goals of this project was to create a resistance against Fusarium wilt in banana. To do so, I first established a greenhouse pathogenicity assay using small banana plantlets that allows quick resistance screening even in small greenhouses in temperate countries. We will publish this method open access so that it can replace current, cumbersome pathogenicity testing, which requires bigger plants and therefore lots of greenhouse space. Genetic engineering of existing cultivars is one solution to combat current threats of banana production. Initially, we planned to introduce a resistance gene and inactivate a susceptibility gene for Foc TR4 to create resistance. Neither of these strategies turned out to be perfect. In contrast to the interaction of tomato with F. oxysporum f. sp. lycopersici, the receptor kinase encoding susceptibility gene does not seem to be a susceptibility gene for banana, since the Foc effector peptide RALF that is targeting this receptor kinase is not a strong virulence factor for Foc. We are currently preparing the manuscript for submission to Molecular Plant Pathology. Likewise, the tomato resistance protein I-3 seems to requires additional tomato factors and is therefore not suitable for transfer in banana. Since, genetically engineered bananas might have faced difficulties with consumer acceptance and would have been difficult to de-regulate, we decided to change our strategy and to explore biologicals as a means to control Fusarium wilt disease.
Biologicals are antagonistic microbial strains or molecules. They are a promising solution to control Fusarium wilt, especially for smallholder farmers, because they are inexpensive and offers potentially season-long disease control. In collaboration with a US biotech company, I successfully identified a bacterial strain that is able to inhibit Foc growth. If this strain is active in field trials, it could become a game changer in the control of banana Fusarium wilt.