This excerpt from the paper "The Plant Immune System" discusses the complex, two-branched defense system plants use against microbial pathogens. The authors describe how plants recognize and respond to pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs), which triggers PAMP-triggered immunity (PTI). However, successful pathogens often deploy effectors that interfere with PTI, leading to effector-triggered susceptibility (ETS). The second branch of plant immunity, effector-triggered immunity (ETI), involves the recognition of pathogen effectors by NB-LRR proteins, which often leads to a hypersensitive response (HR) and the arrest of pathogen growth. The paper goes on to examine various mechanisms of host recognition, including both direct and indirect recognition of effectors, and discusses how pathogens evolve to evade host surveillance. It highlights the ongoing co-evolutionary arms race between plants and their pathogens and explores the potential for future research in this field.
