AUTHOR=Zhou Beibei , Zou Yue , Ma Jie , Li Yanping , Pan Ke TITLE=Toxicity and Bioaccumulation of Copper in Phaeodactylum tricornutum Under Different Macronutrient Conditions JOURNAL=Frontiers in Marine Science VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.907114 DOI=10.3389/fmars.2022.907114 ISSN=2296-7745 ABSTRACT=

In this study, we investigated cell physiological and biochemical responses to copper (Cu) accumulation in the marine diatom Phaeodactylum tricornutum under different nitrogen (N) and phosphorus (P) conditions. Cells with sufficient N and P (+N+P) showed the highest total Cu concentrations and displayed a higher metal-tolerance ability. In the +N+P treatments, 36.5% of dissolved Cu was adsorbed on the frustules (cell walls), 54.9% was occluded in organelles, and 8.6% was in the soluble fraction. In comparison, cells with N and/or P shortages (+N−P, −N+P, and −N−P) adsorbed 10.8–13.1% of the total Cu onto their cell walls, 74.5–80% was occluded in organelles, and 9.2–12.4% was in the soluble fraction. The Cu2+ influx on the +N+P cell wall was faster due to sufficient metal ligands on the cell walls and up-regulated metal-related transporters. A significant increase in protein content occurred under N and/or P shortages, which was accompanied by the inhibition of the antioxidative enzymatic system and cell membrane damage. Our findings indicate that N and P play an important role in both Cu adsorption (cell surface) and uptake (intracellular), and they provide multifaceted evidence of the Cu acquisition mechanism in P. tricornutum under different macronutrient conditions.