Peptide signaling for drought-induced tomato flower drop

Fruit abscission in response to drought Plants faced with drought, or simply not quite enough water, may be more likely to drop their fruit prematurely. Reichardt et al. found that a small signaling peptide hormone, phytosulfokine, which was previously known for its ability to regulate plant cell growth, also drives fruit abscission. Processed, and thus activated, by a subtilisin-like protease, phytosulfokine in turn drives expression of the hydrolases that degrade the cell walls in the abscission zone, leading to dropped fruit. Science , this issue p. 1482