Specific modulation of the root immune system by a community of commensal bacteria.

Plants have an innate immune system to fight off potential invaders that is based on the perception of nonself or modified-self molecules. Microbe-associated molecular patterns (MAMPs) are evolutionarily conserved microbial molecules whose extracellular detection by specific cell surface receptors initiates an array of biochemical responses collectively known as MAMP-triggered immunity (MTI). Well-characterized MAMPs include chitin, peptidoglycan, and flg22, a 22-amino acid epitope found in the major building block of the bacterial flagellum, FliC.

A complex immune response to flagellin epitope variation in commensal communities.

Immune systems restrict microbial pathogens by identifying "non-self" molecules called microbe-associated molecular patterns (MAMPs). It is unclear how immune responses are tuned to or by MAMP diversity present in commensal microbiota. We systematically studied the variability of commensal peptide derivatives of flagellin (flg22), a MAMP detected by plants.

Signatures of antagonistic pleiotropy in a bacterial flagellin epitope.

Immune systems respond to "non-self" molecules termed microbe-associated molecular patterns (MAMPs). Microbial genes encoding MAMPs have adaptive functions and are thus evolutionarily conserved. In the presence of a host, these genes are maladaptive and drive antagonistic pleiotropy (AP) because they promote microbe elimination by activating immune responses.

Beyond pathogens: microbiota interactions with the plant immune system.

Plant immune receptors perceive microbial molecules and initiate an array of biochemical responses that are effective against most invaders. The role of the plant immune system in detecting and controlling pathogenic microorganism has been well described. In contrast, much less is known about plant immunity in the context of the wealth of commensals that inhabit plants.