1. a plant hormone that regulates stress responses, seed dormancy, and leaf abscission; also called abscisic acid.
Usage: biology; botany; also abbreviated as ABA

Examples

• Abscissin levels increase in plants during drought stress.
• The hormone abscissin helps regulate when leaves fall from trees in autumn.
• Scientists study abscissin to understand how plants respond to environmental changes.
• Abscissin plays a key role in seed dormancy and germination.
• High concentrations of abscissin can trigger stomatal closure to conserve water.