Coumarin Inhibits Primary Root Growth by Modulating Auxin Signaling via Neddylation.

ABSTRACT: The allelopathic compound coumarin inhibits root growth across numerous species, but its mechanism is unknown. Through a genetic screen in Arabidopsis mutants, we identified the mutants for AXR1 (AUXIN RESISTANT 1) and ECR1 (E1 C-TERMINAL RELATED 1), two subunits of the NEDD8-activating enzyme (NAE), that are resistant to coumarin. Conversely, overexpression of the NEDD8-encoding gene RUB1 (RELATED TO UBIQUITIN 1) caused hypersensitivity, while the NAE inhibitor MLN4924 blocked coumarin's effect. Since neddylation regulates auxin signaling, we analyzed downstream AUX/IAA proteins and found that the loss-of-function mutant of AUXIN RESISTANT 2 (AXR2) (also known as IAA7) was resistant to coumarin. We further showed that coumarin treatm

SUBMITTER: Liu S 

PROVIDER: S-EPMC12730241 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature