The quick and the dead: a new model for the essential role of ABA accumulation in synthetic auxin herbicide mode of action

摘要

The synthetic auxin herbicides mimic endogenous auxin and have been used for weed control in crop, turf, and non-crop systems for decades (Busi et al., 2018; Peterson et al., 2016). Questions remain regarding a precise description of the mode of action of synthetic auxin herbicides, specifically about the sequence of events/processes leading to plant death. McCauley et al. (2020) propose that rapid up-regulation of 9-cis-epoxycarotenoid deoxygenase (NCED) leading to rapid abscisic acid (ABA) synthesis and prolonged ABA accumulation followed by a general repression of photosynthesis-related transcription, and eventual leaf senescence is the primary mode of plant death for synthetic auxin herbicides.