How do mycorrhizal fungi help the plants harbouring them?

Mycorrhiza does not help the host plant in :

How is the mycorrhizal assoication helpful in absorption of water and minerals in plants?

How do mycorrhizae act as biofertilizers? Explain. Name a genus of fungi that forms a mycorrhizal association with plants.

How do the plants check the pollution?

How is the mycorrhizal association helpful cellif it is kept ina solution having higher water potential.