The activity of a pathogen-derived entity that interacts with a host receptor to activate effector-triggered immunity.
Source:PMID:20601497
Comment
Note that this term is meant to annotate effectors for which the evolved activity is to act as a ligand to activate (for necrotrophs) or suppress (for biotrophs) the host immune system. It should not be used to annotate PAMPs (pathogen-associated molecular pattern molecules) or similar types of microbial proteins recognized by the host innate immune system (for example, PAMPs are recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) in both plants and animals). PAMPs activate innate immune responses, protecting the host from infection, but this is not the molecular function of PAMPs; those usually form the structure of the bacterial cell wall.