Neophaseic acid catabolism in the 9'-hydroxylation pathway of abscisic acid in Arabidopsis thaliana.

ABSTRACT: Abscisic acid (ABA) hydroxylation is an important pathway for ABA inactivation and homeostasis maintenance. Here, we discover a new downstream catabolite of neophaseic acid (neoPA) in the ABA 9'-hydroxyl pathway and identify it as epi-neodihydrophaseic acid (epi-neoDPA) by comparing its accurate mass, retention time, and MSⁿ spectra with those of our chemically synthesized epi-neoDPA. Analyses of Arabidopsis seed germination and ABA-related gene expression reveal that neoPA rather than epi-neoDPA possesses ABA-like hormonal activity. In vitro enzyme activity tests of prokaryotic recombinant protein reveal that NeoPAR1 (neoPA reductase 1) identified from Arabidopsis converts neoPA into epi-neoDPA. Site-directed mutation at Tyr163 in the conserved motif of NeoPAR1 abolishes the ca

SUBMITTER: Bai YL 

PROVIDER: S-EPMC9482987 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature