Engineering resistance to sigatoka

Abstract

Bananas and plantains are the major staple food in the tropical and subtropical regions. Currently the global banana production is affected by both quality- and yield-limiting by foliar fungal disease, the black sigatoka caused by Mycosphaerella fijiensis. The management of the disease by chemical approach has been relatively successful; however indiscriminate usage of chemicals has negative impact on human life and environment. Heavy reliance on fungicides has increased the chance of development of pathogen resistance. The conventional breeding approach can be a relatively impressive strategy in the development of disease-resistant cultivars, but it has become increasingly difficult due to male sterility, narrow genetic bases, and polyploidy nature. The advances in molecular biological techniques have provided the deeper insights into pathogen and plant defense mechanism, which have opened new avenue for the improvement of banana through genetic engineering. In the current review, the potential strategies used to enhance the resistance to sigatoka through genetic engineering employing different approaches like overexpression of pathogenesis-related protein (PR) antifungal proteins and bacterial hydrolytic enzymes and utilization of RNAi-mediated gene silencing of pathogenesis-related protein encoded by pathogens are summarized.