The transcriptomic analysis revealed sulfamethoxazole stress at environmentally relevant concentration on the mechanisms of toxicity of cyanobacteria Synechococcus sp

Abstract

The study addressed the mechanisms of toxicity induced to cyanobacteria Synechococcus sp by its exposure to sulfamethoxazole (SMX). Here, transcriptomics analysis was used to investigate variations in the molecular level of Synechococcus sp under SMX stress at concentrations of 0.5 and 10 μg L−1. There were insignificant differences in algal density between 0.5 μg L−1 and the control group, whereas a conspicuous reduction of 56% in the 10 μg L−1 group was discovered. Additionally, 12 and 133 differentially expressed genes (DEGs) were found in the different treatment groups. Experimental results show that SMX at the environmentally realistic concentration may not disrupt the algal physiological status. Cyanobacteria are similar to bacterial in structure, and SMX has been recognized antibacterial effect of inhibiting folate synthesis. However, DEGs were dominantly enriched in the porphyrin and chlorophyll metabolism, photosynthesis, selenocompound metabolism, and tocopherol biosynthesis rather than folate biosynthesis pathway, indicating SMX has different mode of action between Synechococcus sp and bacteria. briefly, the Synechococcus sp was used as model organisms to reveal the mechanism of SMX.