Loss of susceptibility as a novel breeding strategy for durable and broad-spectrum resistance

Abstract

Recent studies on plant immunity have suggested that a pathogen should suppress induced plant defense in order to infect a plant species, which otherwise would have been a nonhost to the pathogen. For this purpose, pathogens exploit effector molecules to interfere with different layers of plant defense responses. In this review, we summarize the latest findings on plant factors that are activated by pathogen effectors to suppress plant immunity. By looking from a different point of view into host and nonhost resistance, we propose a novel breeding strategy: disabling plant disease susceptibility genes (S-genes) to achieve durable and broad-spectrum resistance.

Fig. 1

Comparison on effector targets with positive or negative roles in plant defense to demonstrate how to obtain resistance by knocking out susceptibility gene. Panel a shows that, in the absence of resistance protein, both presence and absence of the effector target (with a positive role in plant defense) lead to susceptible plants. Panel b demonstrates that, in the absence of resistance protein, presence of the effector target (with a negative role in plant defense) leads to susceptible plants and that knocking out the effector target leads to resistant plants