Insect and nematode resistance

Abstract

Crops are attacked by parasitic pests, including insects and nematodes causing considerable economic losses worldwide. The global yield loss of crops due to herbivorous insects varies between 5% and 30% depending on crop species, while the economic losses due to plant parasitic nematodes are about US $125 billion annually. Today, the control of plant parasites mainly depends on relatively few chemicals that pose serious concerns of risks and hazards for humans, animals and the environment and also increase the costs of growing crops. Use of natural resistance mechanisms offers a promising alternative for parasite control. A set of resistance genes has been identified. Advanced understandings of natural resistance mechanisms in molecular details broaden the horizon of crop resistance breeding programs. Because the resistance resource is limited in many crop species and gene-for-gene reliant resistance is easily overcome by new virulent pathotypes, new genetic variability is needed. Therefore, engineered resistance is becoming an essential part of a sustainable parasite control as it offers a parasite management with benefits to the producer, the consumer and the environment. For engineering resistance, several approaches are under discussion and application. This review focuses on the strategy for engineering parasite resistance in crops by genetic modification.