Question

Explain the steps involved in the formation of root module.

Answer 1

Roots of legume release sugars, amino acids which attracted Rhizobium. They get attached to epidermal and root hair cells of the host.

The root hair curl and the bacteria invade the root hair.

An infection thread is produced, carrying the bacteria into the cortex of the root.

Bacteria initiate nodule formation in the cortex of the root. Then the bacteria released from the thread to the differentiation of specialised nitrogen-fixing cells,

The nodule thus formed establishes a direct vascular connection with the host for the exchange of nutrients.