Unraveling the role of effectors from Fusarium spp. in Fusarium wilt of banana

Fusarium wilt of banana (FWB) is caused by a suite of soil-borne Fusarium, which invade the roots and colonize the vascular system eventually leading to plant death. Currently, eleven distinct Fusarium species cause FWB in various banana accessions. However, F. odoratissimum -also known as Tropical race 4 (TR4)-, which kills Cavendish bananas, and many others, is the prime global threat for banana cultivation. There are no effective control methods for FWB; there are no functional commercial fungicides, biocontrol is ineffective and there are no commercial banana varieties resistant to TR4. It is crucial to unravel the mechanisms underlying disease development that might aid in efficient disease management strategies. One of these strategies relies on effectors, which are in planta-secreted molecules. For instance, SIX proteins (For secreted in xylem) are secreted by pathogenic Fusarium spp. and contribute to virulence on banana. Comparative genomic and transcriptomic analyses revealed that Six genes are differentially expressed in F. odoratissimum (isolate II-5) and F. phialophorum (Isolate CR1.1A). Both isolates show a differential interaction with cavendish bananas (compatible with II-5 and incompatible with CR1.1A). Interestingly, Six6 is only upregulated in the compatible interaction. Cell death responses were observed after agro-infiltrations with Six6 in Nicotiana benthamiana. We hypothesize that Six6 might might have an important role in the virulence of isolate II-5 on banana. Overall, this work aims to understand the interaction between effectors of Fusarium spp. and banana, which is crucial for the design of novel management options for FWB