A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield. RNA interference (RNAi) strategy is used to prevent this infestation. 

RNAi is a process by which double-stranded RNA (dsRNA) directs sequence-specific degradation of mRNA. It prevents translation of a specific mRNA (silencing) due to a complementary dsRNA molecule. The source of this complementary RNA is from an infection by RNA viruses or mobile genetic elements (transposons) that replicate via an RNA intermediate.

Using Agrobacterium vectors, nematode-specific genes (DNA) were introduced into the host plant (Tobacco plant). Introduction of DNA produces both sense and anti-sense RNA in the host cells. These two RNAs being complementary to each other formed a double stranded (dsRNA) that initiated RNAi and thus, silenced the specific mRNA of nematode' The consequence was that the parasite cannot survive in a transgenic host expressing specific interfering RNA.