CBSE Class 12-science Answered

Pest Resistance in Transgenic Plants:

• The nematode Meloidogyne incognita infects the roots of tobacco plants and causes a reduction in yield.
• A unique strategy based on RNA interference (RNAi) involves the silencing of a specific mRNA.
• Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant.
• The introduction of DNA produced both sense and antisense RNA in the host cells.
• These two RNAs being complementary to each other formed a dsRNA which initiated RNAi and thus, silenced the specific mRNA of the nematode.
• As a result, the parasite could not survive in a transgenic host expressing specific interfering RNA. 
• In this way, the transgenic plant itself is protected from the parasite.