Production, Use and Biosafety of Genetically
Engineering Resistance to Plant Virus Diseases
One successful application of genetic engineering in crop improvement is in the production of virus-resistant plants. This has been achieved by genetic transformation of plants with novel resistance genes based on nucleotide sequences derived from the viruses themselves or from virus-associated nucleic acid as well as genes from other sources.
The demonstration that the expression of tobacco mosaic virus (TMV) coat protein (CP) in transgenic plants protects the plants against virus infection 1 has led to explorations of using other viral or virus-associated genes in producing genetically engineered resistance against in plant virus. Transgenic plants expressing Sat-RNAs have been obtained in a number of laboratories and have been tested in greenhouses and fields. 2 Recent studies with defective interfering RNA or DNA protection and sense-antisense-ribozyme RNA- mediated protection offer much promise for a broad range virus resistance in plants. 3
Our laboratory has successfully produced satellite RNA-mediated resistance to cucumber mosaic virus (CMV) in tobacco and tomato, CP-mediated resistance to rice stripe virus in rice and fusion protein (CP and nuclease) mediated high resistance to tobacco mosaic virus in tobacco. One way to confer more effective and durable field resistance to virus disease in transgenic crop is to use a combination of multiple resistance genes.
and monitoring the risks of releasing genetically manipulated plants will be