(i) Growth promotion Fungus produces growth promoting hormones. In the absence of this association, Pinus and Betula show stunted growth despite providing all types of nutrients.
(ii) Antimicrobial substance Fungus protects the root from parasitic fungi and harmful bacteria by secreting antimicrobial substances.
(iii) Nourishment In orchids, the fungus absorbs nourishment from outside and hands over it to germinating seed.
(iv) Adverse environment Allow plants to grow in mineral deficient soil, saline soil, unfavourable pH and temperature.
(v) Absorption of water Fungal association increases water availability to the root.