RNAi technology for management of banana bunchy top disease

Abstract

Banana bunchy top disease (BBTD) is one of the world's most destructive viral diseases of banana and plantain, causing up to 100% yield loss in severe cases. The disease is vectored by banana aphids (Pentalonia nigronervosa) and carried long distances through the movement of infected plant materials. The banana aphids harboring banana bunchy top virus (BBTV) present in banana producing regions are the sole vector and the most efficient method of transmitting the virus to the healthy plants. Controlling the spread of BBTD has been very challenging since no known banana germplasm is immune to BBTV. The disease can be managed with the use of virus-free planting material and roguing. However, once BBTD is established in the field, it is very difficult to eradicate or manage it. Therefore, a more sustainable way of controlling the disease is developing host plant resistance against the virus and the vector. Biotechnological strategies via RNA interference (RNAi) could be used to target the banana aphid as well as BBTV to reduce virus-associated yield losses of banana and plantain, which feed over 500 million people around the world. This review discusses the status of BBTD and perspectives on effective RNAi technologies for controlling BBTV and the vector, banana aphid, transmitting the virus as sustainable management of the disease.

Keywords: RNA interference; banana; banana aphid; banana bunchy top disease; banana bunchy top virus; plantain.

FIGURE 1

Global distribution of Banana Bunchy Top Disease (BBTD). Red color represents countries where BBTD has been reported

FIGURE 2

Genomic composition and effects of Banana bunchy top virus (BBTV) on the host plant. (a) Genomic organization of six ssDNA components of BBTV, (b) symptomatic banana plant showing stunted growth due to banana bunchy top disease

FIGURE 3

A representation of different approaches of RNAi delivery for control of the banana bunchy top disease. (a) Transgenic banana expressing RNAi targeting BBTV and/or aphids transmitting the virus, (b) nontransgenic approach of dsRNA topical spray for control of Banana bunchy top virus and/or aphids