Question : Give information about pest resistant plants. OR Explain RN

1.	Question : Give information about pest resistant plants. OR Explain RNA interference.
Answer» Solution :SEVERAL nematodes parasitise a WIDE variety of plants and animals including human beings. A nematode meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield. A NOVEL strategy was adopted to prevent this infestation which was based on the process of RNA interference. RNAi takes place in all eukaryotic organisms as a method of cellular defense. This method 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 air infection by viruses having RNA genomes or mobile genetic elements (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 antisense RNA in the host cells. These two RNA.s being complimentary to each other formed a double stranded (dsRNA) that initiated RNAi and thus silenced the specific mRNA of the nematode. The consequence was that the parasite could not servive in a transgenic host expressing specific interfering RNA. The transgenic plant therefore got itself protected from the parasite:

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