Molecular genetic mechanisms of interaction between host plants and pathogens.

Abstract

In recent years, a great number of plant resistance (R) genes and pathogen avirulence (Avr) genes were identified. Exciting breakthroughs were also made on the structural and functional analysis of R proteins and Avr proteins, and the mechanistic interaction between them. Plants have evolved two layers of the immune system to cope with pathogens in the evolutionary processes, which are pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI). In PTI responses, conserved PAMPs are recognized by plant plasma membrane-localized pattern recognition receptors (PRRs) and disease resistance is activated. Furthermore, the ETI immune signaling is activated by the recognition of pathogen Avr proteins by the host R proteins, which usually results in hypersensitive responses at the infection site. In this review, we summarize the progresses on PTI and ETI, and discuss the genetic mechanism of the interaction between plant R gene and pathogen Avr gene in detail. We also envision the new challenges and propose the new strategies for the future investigations on plant resistance molecular breeding.