Chitin Signaling in Plants: Insights into the Perception of Fungal Pathogens and Rhizobacterial Symbionts

摘要

In addition to the R gene–mediated pathways of plant resistance to specific pathogens, plants have the capacity to recognize a number of microbial surface-derived molecules, which elicit a general immune response in both host and nonhost plants. These are known as pathogen-associated or microbe-associated molecular patterns (PAMPs/MAMPs), so named because they are presumed to contain a structure or a pattern that is absent from eukaryotic host molecules and allows the host to recognize a microbial (and potentially pathogenic) invader. Many PAMPs that have been identified are essential for microbial metabolism or for penetration and invasion of a host cell and are therefore broadly conserved among diverse microbial pathogens (Parker, 2003). These include lipopolysaccharides of Gram-negative bacteria, peptidoglycans from Gram-positive bacteria, eubacterial flagellin, and glucans, chitins, and proteins derived from fungal cell walls (Nürnberger and Brunner, 2002).