Genetic engineering technologies to control viruses and their application to cassava viruses
1993
Fauquet, C.M. | Schopke, C. | Chavarriaga A, P. | Sangare, A. | Beachy, R.N.
Resistance to plant viruses through genetic engineering has been investigated with the application of four different approaches. A recent approach is the use of ribozymes, which involves using catalytic RNAs to cause the cleavage of viral RNA molecules. Results of in vitro experiments have documented cleavage of viral RNAs but in vivo experiments has thus far not been reported. The second technique is to attempt to block the translation of viral RNAs by expressing genes that encode sequences complementary (i.e. antisense) to viral genes. Only a limited number of cases have been reported, but little success has been documented. A third approach is to block virus replication, using competitor sequences, subgenomic sequences and satellite RNAs. The last technique is the expression of viral genes which will interfere with virus replication and/or, diffusion in the plants; replicase gene, movement proteins and capsid proteins. The most promising technique is that of the coat protein (CP), which consists of the integration of a gene encoding viral coat protein into the plant genome. An increasing number of examples using the coat protein mediated resistance (CPMR) strategy are available, and resistance specificity and efficacy have been evaluated for viruses belonging to thirteen groups; furthermore, several successful field experiments have been conducted
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