Dichlofenac altered root developmental processes of Arabidopsis via interfering with the hormonal activities of auxin
Diclofenac, a pharmaceutical product, is detected in various environmental matrices and regarded as potential pollutant worldwide. Increased irrigation of water in agriculture has facilitated accumulation of environmental diclofenac inside green fresh products, which potentially threatens non-target
organisms including human. In current study, we demonstrated that diclofenac inhibited the growth and altered root developmental processes of plants in a similar but competitive way to auxin, a group of major phytohormones. Exogenously treated diclofenac caused oxidative stress in Arabidopsis
seedlings. In developmental point of view, diclofenac modified the root system architecture such as primary and lateral roots. The effects of diclofenac on the root development of Arabidopsis were mediated through canonical auxin signaling pathways. Interestingly, when diclofenac and auxin were used in
combination, diclofenac suppressed the activity of auxin. Conclusively, diclofenac acted as a weak agonist of auxin in the root development of Arabidopsis, but interfered with natural auxin activities via competitive association with auxin signaling factors. Such results suggested that diclofenac could potentially
behave as an environmental hormone by disturbing the natural developmental processes of plants.