Question

Short / Long answer type questions.
Describe the association known as mycorrhizae, and explain how each partner benefits.

Answer 1

The mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose supplied by the plant. The carbohydrates are translocated from their source to root tissue and on to fungal partners. In return, the plant gains the benefits of the mycelium's higher absorptive capacity for water and mineral nutrients (due to the comparatively large surface area of mycelium: root ratio), thus improving the plant's mineral absorption capabilities. Plant roots alone may be incapable of taking up phosphate ions that are demineralized, for example, in soils with a basic pH. The mycelium of the mycorrhizal fungus can, however, access these phosphorus sources, and make them available to the plants they colonize.