Question

Nematode-specific genes are introduced into the tobacco plants using Agrobacterium vectors to develop resistance in tobacco plants against nematodes. Explain the events that occur in tobacco plant to develop resistance.

OR

How has RNAi technique helped to prevent the infestation of roots in tobacco plants by a nematode Meloidegyne incognitia?

Answer 1

• A nematode Meloidegyne incognitia infects the roots of tobacco plants which reduces the production of tobacco.

• It can be prevented by using RNA interference (RNAi) process which is checked by silencing of specific mRNA due to a complementary dsRNA.

• dsRNA binds and prevents translation of the mRNA (silencing).

• By using Agrobacterium vectors, nematode-specific genes were introduced into the host plants which produce both sense and anti-sense RNA in the host cells.

• These two RNAs are complementary to each other and form a double-stranded RNA (dsRNA) that initiates RNAi and hence silence the specific mRNA of the nematode.

• The parasite cannot survive in the transgenic host, so protects the plants from pests.