摘要
As an important class of engineered nanomaterials, CuO nanoparticles have found broad use across various areas, while their toxicity has drawn attention. Although previous studies have reported the environmental fate of CuO particles and their ecotoxicity to algae, whether particle size modulates the aquatic toxicity of CuO particles and how algae coordinate detoxification responses under particle stress remain incompletely understood within a unified framework. In this study, physiological and transcriptomic analyses were combined to compare the toxic effects of two CuO particle size fractions, CuO-NPs (40 nm) and CuO-SMPs (150–250 nm), on Chlamydomonas reinhardtii (C. reinhardtii), and to investigate the detoxification responses of this alga at both cellular and molecular levels. The results revealed that, under the tested conditions, the CuO-NPs fraction induced stronger growth inhibition, photosynthetic damage, and oxidative stress than the CuO-SMPs fraction. At 50 mg L−1, the growth inhibition rates caused by CuO-NPs and CuO-SMPs reached 40.84% and 31.60%, respectively. RNA-seq analysis revealed 1054 differentially expressed genes, comprising 302 upregulated and 752 downregulated ones, which were mainly enriched in oxidation–reduction processes and oxidoreductase activity. By integrating physiological endpoints with transcriptomic responses, we further outlined a relatively complete detoxification route employed by C. reinhardtii under CuO particle stress, involving peroxisome regulation, activation of the ascorbate–glutathione cycle, phytochelatin chelation, and ABC transporter-mediated compartmentalized sequestration. This study provides new insight into the molecular detoxification mechanisms of microalgae under nanoparticle stress and contributes to a more complete understanding of the bidirectional interaction between CuO-NPs and aquatic microalgae.
危险品化学品经营许可证（带存储）