How to effectively deploy plant resistances to pests and pathogens in crop breeding

Food shortage is currently a serious worldwide problem, and the fact that it will become an even greater problem in the coming decades underscores the necessity for more translational research in plant sciences that is directed towards crop breeding. Biotic stresses are important determinants of reduced crop production and, therefore, a better understanding of the resistance mechanisms utilized by plants to survive and remain productive following attacks by pathogens and pests is a major research goal of plant scientists and crop breeders. During the last two decades tremendous progress has been made in this field. Here we first summarize recent findings on how plants respond to their pathogens and pests and then we discuss resistance mechanisms in three categories based on differences in spectrum, durability and evolution. We also review different breeding strategies that have been adopted on the basis of these findings for improving resistance to pests and pathogens in crops and evaluate these strategies for their sustainability.