Study of the volatile organic compounds in the interaction between banana plants and the fungal disease Fusarium oxysporum f.sp. cubense Tropical Race 4 (FocTR4)

Banana fruit (Musa sp.) ranks fourth in term of worldwide production, and has economical and nutritional key values. Cavendish is the popular and most dominant variety of the dessert banana group. Nowadays, it is endangered by the emergent race of the Panama disease, caused by Fusarium oxysporum f.sp. cubense TR4 (Foc TR4). Despite the importance of the Volatile Organic Compounds (VOCs), which are secondary metabolites with a high vapour pressure, and their role in plant protection, they have never been documented as a way to manage this disease on Cavendish. Thus, the aim of this PhD thesis is to study the VOCs in the specific interaction Cavendish/Foc TR4, as a way to manage this threat. Based on the work previously done with other plants at Gembloux Agro-Bio Tech, a protocol was optimized for the extraction of the banana plant’s VOCs. In parallel, models of in-vitro and in-vivo inoculations are under development to distinguish the VOCs emitted by the root zone and those emitted by the aerial part of the plant. The results of the first analysis showed that the majority of the Cavendish VOCs belongs to the terpenes group, as well as ketones and an organic ester. The VOCs specifically emitted during the plant-pathogen interaction will be studied more in depth by evaluating their effect on the plant and the pathogen. At long term, and depending on the results, agro-ecological applications of this knowledge could include breeding for new variety or combining banana with other plants expressing VOCs against Foc TR4, applying VOCs on field to stimulate plant defences or to contain the pathogen.