Stress symptoms and plant hormone-modulated defense response induced by the uptake of carbamazepine and ibuprofen in Malabar spinach (Basella alba L.)

Abstract

Due to their wide applications and extensive discharges, pharmaceuticals have recently become a potential risk to aquatic and terrestrial organisms. The uptake of pharmaceuticals have been shown to stimulate plant defense systems and induce phytotoxic effects. Signaling molecules such as plant hormones play crucial roles in plant stress and defense responses, but the relationship between these molecules and pharmaceutical uptake has rarely been investigated. In this study, two common pharmaceuticals, carbamazepine and ibuprofen, and three stress-related plant hormones, jasmonic acid, salicylic acid, and abscisic acid, were simultaneously tracked in the roots and stems of Malabar spinach (Basella alba L.) via an in vivo solid phase microextraction (SPME) method. We also monitored stress-related physiological markers and enzymatic activities to demonstrate plant hormone modulation. The results indicate that pharmaceutical uptake, subsequent stress symptoms, and the defense response were all significantly correlated with the upregulation of plant hormones. Moreover, the plant hormones in the exposure group failed to recover to normal levels, indicating that plants containing pharmaceutical residues might be subject to potential risks.