VAM Spore: Spores are produced at the tips of hyphae either within the host root or outside the root in the soil. Thought to be chlamydospores, these spores germinate and the germination tube that is produced grows through the soil until it comes into contact with roots. The fungus then penetrates the root and grows between root cells, or it may penetrate the cell wall and grow within root cells. Inside the root, the fungus forms arbuscules, which are highly branched hyphal structures that serve as sites of nutrient exchange with the plant.