biostudies-literatureBelda-Palazon BMICINNBiotechnology and Biological Sciences Research CouncilE11857-E11863https://www.ebi.ac.uk/biostudies/studies/S-EPMC6294950biostudies-literatureUnknown115(50)The phytohormone abscisic acid (ABA) plays a key role regulating root growth, root system architecture, and root adaptive responses, such as hydrotropism. The molecular and cellular mechanisms that regulate the action of core ABA signaling components in roots are not fully understood. ABA is perceived through receptors from the PYR/PYL/RCAR family and PP2C coreceptors. PYL8/RCAR3 plays a nonredundant role in regulating primary and lateral root growth. Here we demonstrate that ABA specifically stabilizes PYL8 compared with other ABA receptors and induces accumulation of PYL8 in root nuclei. This requires ABA perception by PYL8 and leads to diminished ubiquitination of PYL8 in roots. The ABA agonist quinabactin, which promotes root ABA signaling through dimeric receptors, fails to stabilize Proceedings of the National Academy of Sciences of the United States of AmericaPYL8 mediates ABA perception in the root through non-cell-autonomous and ligand-stabilization-based mechanisms.PMC6294950BB/G023972/1BIO2014-52537-RBB/M002136/1BIO2017-82503-RBB/J009717/1BIO2015-64307-RRodriguez LBerbel ALozano-Juste JMadueno FCoego AAntoni RJulian JDietrich DBennett MJFernandez MAGonzalez-Garcia MPBelda-Palazon BRodriguez PLPeirats-Llobet MfalsePYL8 mediates ABA perception in the root through non-cell-autonomous and ligand-stabilization-based mechanisms.The phytohormone abscisic acid (ABA) plays a key role regulating root growth, root system architecture, and root adaptive responses, such as hydrotropism. The molecular and cellular mechanisms that regulate the action of core ABA signaling components in roots are not fully understood. ABA is perceived through receptors from the PYR/PYL/RCAR family and PP2C coreceptors. PYL8/RCAR3 plays a nonredundant role in regulating primary and lateral root growth. Here we demonstrate that ABA specifically stabilizes PYL8 compared with other ABA receptors and induces accumulation of PYL8 in root nuclei. This requires ABA perception by PYL8 and leads to diminished ubiquitination of PYL8 in roots. The ABA agonist quinabactin, which promotes root ABA signaling through dimeric receptors, fails to stabilize 2018-01-01T00:00:00Z2018 Dec2026-05-05T22:55:59.293Z2019-09-14T07:00:34ZS-EPMC62949503048286310.1073/pnas.1815410115