Mechanisms of autophagy and cell death in plant immunity
daniel_hofius_portraitPlants, unlike animals, lack adaptive immune mechanisms and solely rely on a multilayered innate immune system to prevent pathogen infection. One layer engages surface receptors that detect conserved pathogen molecules of bacterial, oomycete or fungal origin to initiate antimicrobial defences. Additionally, antiviral immunity involves recognition and degradation of viral genomes by the RNA silencing machinery. Successful pathogens inhibit these basal immune responses by the delivery of effector proteins or silencing suppressors inside the host cell. Plants have therefore developed another defence layer to detect effector modification of host targets via different immune receptors (resistance or R proteins). These potentiate disease resistance in association with a localized programmed cell death reaction, known as the “hypersensitive response” (HR). Many key factors of the HR have been identified but the molecular mechanisms and pathways of cell death execution remain poorly understood.