Damage on plants activates Ca 2+ -dependent metacaspases for release of immunomodulatory peptides

Rapid response to tissue damage Damaged plants are susceptible to microbial attack. In response to physical damage, plants proactively generate signal peptides to activate their immune systems. Hander et al. examined wound responses in the model plant Arabidopsis thaliana . They identified a metacaspase that releases an immunomodulatory signal peptide from its precursor form within 30 seconds of the damage. The metacaspase itself was activated by a burst of calcium released by tissue damage. Science , this issue p. eaar7486