The Primary function of the root is absorption of water and minerals and giving mechanical support to the plant. Sometimes roots get modified to carry out other functions like storage of food or additional mechanical support.
1. Banyan Tree. In banyan trees long roots develop from branches and they hanging deep down to reach the ground. They are providing additional mechanical support to the huge banyan tree. This modification is called a prop root.
2. Turnip. In turnip the root is modified to store extra food.
3. Mangrove Trees. Mangrove trees are found in marshy area. The roots are modified into pneumatophore providing extra passage to allow additional oxygen to the plant.