The avoidance response in plant root to the environmental pollutant triclosan

Triclosan (TCS), an antimicrobial agent commonly found in personal care products and disinfectants, has raised concerns due to its potential risks for human health and environment. In this study, we observed and investigated an avoidance response in Arabidopsis roots, which exhibited directional growth away from TCS-containing medium. Genetic screening of the mutants impaired in salt stress, abscisic acid (ABA), cytokinin, and auxin signaling pathways revealed that polar auxin transport is essential for mediating this TCS-induced root response. Notably, TCS application downregulated the expression level of auxin transporter proteins AUX1 and PIN2 in the root meristem. These findings highlight the regulatory role of polar auxin transport in directing root growth reorientation in response to TCS, enabling plants to avoid from adverse environmental conditions. Deciphering the molecular mechanisms underlying plant responses to environmental pollutants offers valuable insights for developing strategies to reduce pollutant uptake and accumulation in crops, thereby enhancing food safety and supporting human health.