Waving hello to pathogens: The dynamics of the spread of plant MAMP-triggered Ca ²⁺ signaling

Waves of Ca²⁺ signals rapidly propagate throughout a plant to help integrate responses to stimuli as diverse as wounding, heat stress, and pathogen attack. In this issue of <i>Science Signaling</i>, Zhang <i>et al</i>. show that bacterial elicitors and physical injury likely use different molecular mechanisms to produce distinct patterns of Ca²⁺ waves, shedding light on how such a universal signal leads to stimulus-specific responses.