The role of PYL genes as core components of abscisic acid signaling in plant abiotic stress response

The PYL gene family, encoding core ABA receptors, plays a pivotal role in abiotic stress adaptation and growth regulation in horticultural crops. By binding ABA via its conserved structural domain, PYL proteins initiate signaling cascades through PP2C phosphatase inhibition, precisely modulating downstream ABA responses. This review systematically examines the functional diversification of PYL members and their stress-responsive expression patterns in horticultural species. PYL participates in physiological processes involved in ABA signal transduction regulation. These include stomatal movement, transcriptional regulation, and metabolic regulation, thereby enhancing tolerance to abiotic stresses encountered in horticultural production, such as drought, salinity, low temperature, and darkness. Furthermore, PYLs also regulate developmental traits such as seed germination and root structure, highlighting their dual role in stress resistance and growth and development. The genetic and regulatory complexity of the PYL family offers valuable targets for molecular breeding in horticulture. Future research should elucidate crop-specific PYL regulatory networks to advance precision breeding strategies for sustainable horticultural systems.