Engineering resistance to viruses

Abstract

Banana viruses are limiting factors for banana production in many countries where bananas are grown. The most devastating viral-caused disease of bananas in Hawaii and many areas of Asia, Africa, and the Pacific is banana bunchy top caused by banana bunchy top virus (BBTV). Once BBTV is present in a plantation, it is very difficult to control. Control of the aphid vector using insecticides is inefficient and expensive and poses environmental risks. Removal of infected plants can effectively limit the spread of the virus but requires identification of early infections and involves increased labor and chemical costs. No naturally occurring resistance is known in banana. New control strategies for the efficient control of BBTV are needed. The recent development of transformation and regeneration systems for banana has made it possible to develop virus-resistant banana plants using genetic engineering. Several groups have investigated this possibility and utilized posttranscriptional gene silencing (PTGS) or RNA interference (RNAi) approaches to generate BBTV resistance in several cultivars. To date, no viable transgenic lines have been developed that display durable BBTV resistance. Recent efforts and approaches to develop BBTV-resistant transgenic banana are reviewed in this chapter, and novel strategies to produce virus-resistant transgenic banana are introduced. Future potentials of using transgenic banana as alternatives for management of banana virus diseases are discussed.