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Question

sir how is this mrna functions in papaya

Submitted by: Kranthi Kumar


Answer

Expert response from David Oppenheimer

Associate Professor, University of Florida

Thursday, 06/11/2014 15:02

In all organisms, mRNA functions in translation of genetic information from the genome into proteins that are used for various functions in the cell. This is also true for papaya. Certain mRNAs that are highly abundant can trigger the plant's "immune system." The plant's response is to destroy these specific mRNAs and prevent the production of the corresponding proteins. Scientists have used this property of mRNA to engineer papaya to be resistant to the papaya ringspot virus. The scientists have put the gene for virus capsid protein in the papaya genome. (The capsid protein is a protein that the virus needs to package its own genome during viral replication in an infected papaya plant.) In the engineered plants, the viral capsid protein gene is expressed and turns on the plant's "immune system" so that any mRNA that produces capsid protein is destroyed, and any infecting virus is prevented from replicating.

The beauty of this system is that only the gene for the capsid protein is transferred to the papaya genome; thus, the effects of this gene are well understood. Because of the prevalence of papaya ringspot virus, non-GM papaya plants are often infected with the virus. Prior to the use of GMO papaya, people consumed virus-infected papaya with no ill effects (which was to be expected, because no known plant virus can cause any harm to animal cells). Consuming GMO papaya is better than virus-infected papaya, because the GMO papaya has only the capsid protein gene, and not the entire virus genome and proteins.