Accumulation, transportation, and distribution of tetracycline and cadmium in rice

Co-exposure to heavy metal and antibiotic pollution might result in complexation and syn-ergistic interactions, affecting rice growth and further exacerbating pollutant enrichment. Therefore, our study sought to clarify the influence of different Tetracycline (TC) and Cad-mium(Cd) concentration ratios (both alone and combined) on rice growth, pollutant accu-mulation, and transportation during the tillering stage in hydroponic system. Surprisingly, our findings indicated that the interaction between TC and Cd could alleviate the toxic ef-fects of TC/Cd on aerial rice structures and decrease pollutant burdens during root elon-gation. In contrast, TC and Cd synergistically promoted the accumulation of TC/Cd in rice roots. However, their interaction increased the accumulation of TC in roots while decreas-ing the accumulation of Cd when the toxicant doses increased. The strong affinity of rice to Cd promoted its upward transport from the roots, whereas the toxic effects of TC re-duced TC transport. Therefore, the combined toxicity of the two pollutants inhibited their upward transport. Additionally, a low concentration of TC promoted the accumulation of Cd in rice mainly in the root tip. Furthermore, a certain dose of TC promoted the upward migra-tion of Cd from the root tip. Laser ablation-inductively coupled plasma mass spectrometry demonstrated that Cd mainly accumulated in the epidermis and stele of the root, whereas Fe mainly accumulated in the epidermis, which inhibited the absorption and accumulation of Cd by the rice roots through the generation of a Fe plaque. Our findings thus provide insights into the effects of TC and Cd co-exposure on rice growth. ?? 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.