From the effective herbicide to the environmental contaminant: A review of recent studies on quinclorac

Quinclorac is a specific auxin herbicide with chloro-quinolinecarboxylic acid structure and has been widely recognized as the preferred option for controlling both broadleaf weed and barnyard grass. However, the extensive application of quinclorac has resulted in the evolution of resistant plants, the frequent detection in the environment, and the hazard to non-target organisms. Consequently, the aim of this review is to comprehensively summarize the recent investigations on quinclorac, so as to help promoting the further study for reasonably employing quinclorac and effectively controlling the related risks. In this review, the action mechanism of quinclorac was discussed based on the structure and property, suggesting the involvements of ethylene, phytohormone and even cyanide in sensitive plants. The evolved resistance might be related to auxin production, gene expression, translocation and metabolism. By establishing the reliable methods in previous studies, the quinclorac residue was widely detected and could cause the obvious toxicity such as physiological changes and oxidative stress. Nevertheless, there is still a lack of the remediation technique, which can be efficiently applied in practical engineering.