Strategies for engineering virus resistance in transgenic plants

Summary Transgenic virus-resistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat protein of tobacco mosaic virus. The introduction of coat protein transgenes has since proved to be an extremely effective and generally applicable approach to engineering virus resistance in crop plants. Extensive field trials with transgenic, virus-resistant tobacco, tomato, potato and cucumber lines have confirmed not only the durability of the resistance under natural conditions but the ease with which virus-resistant lines retaining the original cultivar traits can be recovered.A number of alternative anti-viral strategies based on transgenes from a surprisingly wide variety of sources have also been developed. These include the use of viral genes coding for proteins involved in the replication cycle and in systemic transport of viruses within the plant, the use of interfering viral RNA sequences, and the use of transgenes derived from plant and animal sources. In the latter category, the use of mammalian antibodies to confer disease resistance in plants is a particularly exciting new development. Considerable progress has also been made towards the molecular cloning of natural anti-viral resistance genes in plants.