Question

“RNA interference has been used to produce transgenic tobacco plants to protect them from the infestation by specific nematodes.” Explain the novel strategy exploited by the biotechnologists.

Answer 1

RNAi involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA. The source of this complementary RNA could be from an infection by viruses having RNA genomes or transposons that replicate via an RNA intermediate.

Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant. The introduction of DNA was such that it produced both sense and anti-sense RNA in the host cells. These two RNA’s being complementary to each other formed a dsRNA that initiated RNAi and thus, silenced the specific mRNA of the nematode.

The consequence was that the parasite could not survive in a transgenic host expressing specific interfering RNA. The transgenic plant therefore got itself protected from the parasite.