Researchers used fluorescently-labeled fungal strains to visualize how banana wilt disease spreads inside banana plants. They found that resistant banana varieties can slow down the fungus by forming blockages (called tyloses) in their water-conducting vessels, though the fungus can still initially enter the plant. The study showed that the rhizome, an underground stem-like structure, is the key location where resistant plants successfully contain the fungus, which helps explain why some banana varieties are naturally more resistant to this devastating disease.