Arrange the steps involved in creating pest-resistant transgenic plants using RNA interference (RNAi).

(A) Binding of complementary RNAs to form double-stranded RNA (dsRNA).
(B) Formation of sense and antisense RNA in the host cells.
(C) Silencing of specific mRNA of the nematode.
(D) Introduction of nematode-specific genes into the host plant using Agrobacterium vectors.

Choose the correct answer from the options given below:

(D), (B), (A), (C)

The correct answer is Option (4) –(D), (B), (A), (C)

(D) Introduction of nematode-specific genes into the host plant using Agrobacterium vectors.

(B) Formation of sense and antisense RNA in the host cells.

(A) Binding of complementary RNAs to form double-stranded RNA (dsRNA).

(C) Silencing of specific mRNA of the nematode.

Several nematodes infect a wide variety of plants and animals including human beings. A nematode Meloidegyne incognitia infects the roots of tobacco plants which reduce the production of tobacco plants and reduces the production of tobacco. Thus, to prevent this infection a strategy is adopted known as RNA interface (RNAi) which takes place in all eukaryotic organisms as a method of cellular defence. This method involves silencing of mRNA due to complementary dsRNA molecule that binds to it and prevents the process of translation of mRNA.

The infection can be prevented using RNA interference process which is checked by silencing of specific mRNA due to a complementary ds RNA. The ds RNA binds and prevents translation of the mRNA. By using Agrobacterium vectors, nematode-specific genes were introduced into the host plants which produce both sense and antisense RNA in the host cells. These two RNAs are complementary to each other and form a double stranded RNA (ds RNA) that initiates RNAi and hence, silences the specific mRNA of the nematode. The parasite cannot survive in transgenic host and so, prevents the plants from pests.