Friend or Foe: Exploring endophytic colonization by the banana pathogen Fusarium odoratissimum TR4 in banana and other plant species.

Global banana production is severely affected by Fusarium Wilt of Banana (FWB), a devastating fungal vascular wilt disease. The responsible pathogen is Fusarium odoratissimum, also known as Tropical Race 4 (TR4). Current control measures are inadequate to stop the fast spread of the disease. To secure the future of banana, there is an urgent need for more resistant banana varieties. Although FWB drastically impacts banana production by aggressively destroying banana plants, the causal agent TR4 can also be a harmless endophytic colonizer of other plants. In contrast to its pathogenic lifestyle, TR4 does not cause disease during its endophytic lifestyle, i.e., it colonizes without causing damage. However, it is unknown how TR4 can harmlessly colonize other pant species, while TR4 colonization of banana plants is destructive. In this research, the endophytic colonization by F. odoratissimum TR4 will be explored. First, an elaborate overview of the colonization by TR4 will be established using a diverse set of plants. Second, RNA-sequencing experiments will be performed to identify key genes, from both the fungus and plant, that are involved in endophytic colonization by TR4. Third, the findings will be validated in a model plant, e.g., Arabidopsis, to confirm the involvement of the fungal and plant genes in endophytic colonization. This research will provide new insights in the interaction of TR4 with banana and other plants. Furthermore, it will contribute to a novel approach to find resistance against TR4 by exploring the contribution of plant genes in facilitating endophytic TR4 colonization.