Rapid local and systemic jasmonate signalling drives initiation and establishment of plant systemic immunity
Successful recognition of pathogen effectors by plant disease resistance proteins (effector triggered immunity, ETI) contains the invading pathogen through a localized hypersensitive response (HR). In addition, ETI activates long-range signalling cascades that establish broad spectrum systemic acquired resistance (SAR). Using a novel and sensitive reporter we have been able to image the spatio-temporal dynamics of SAR. We demonstrate that local ETI triggered SAR signal generation, followed by rapid propagation and establishment in systemic responding leaves, is dependent on both jasmonate biosynthesis and perception. Further, ETI initiates calcium- and jasmonate-dependent systemic surface electrical potentials, reminiscent of those activated by herbivory but with slower propagation kinetics. Thus, jasmonate signalling is crucial to the initiation and establishment of systemic defence responses against a diverse range of phytopathogens.