What is RNA interference? How does RNA interference helps to develop resistance in tobacco plant against Nematode infection?

Explanation

The silencing of specific m-RNA due to a complementary ds RNA molecule that binds and prevents translation of m-RNA is called RNA interference.
A nematode Meloidegyne incognitia infects the roots of tobacco plants and reduce their yield. Nematode specific genes were introduced into the host plant using Agrobacterium vectors. The introduced DNA produces both sense and antisense RNA in the host cells.
These two RNAs being complimentory to each other formed a double standard RNA (ds. RNA) that initiates RNA i and silenced the specific mRNA of the nematode.
The parasite could not survive in a transgenic host and the transgenic host and the transgenic plant got itself protected from the parasite.