Q.9:- What are the steps involved in formation of a root nodule?
Development of root nodules happens in following steps:
- Rhizobium bacteria contact a susceptible root hair and divides near it.
- Successful infection of the root hair results in curling of the root hair.
- The infected thread carries the bacteria to the inner cortex. The bacteria get modified into rod-shaped bacteroids and cause inner cortical and pericycle cells to divide. Division and growth of cortical and pericycle cells lead to nodule formation.
- A mature nodule is complete with vascular tissues. The vascular tissues of the nodule are continuous with those of the root.