title: Ammonium reduces chromium toxicity in the freshwater alga Chlorella vulgaris.
abstract: The aim of the present study was to investigate the protective effect of ammonium (NH4 (+)) on Cr toxicity to the freshwater alga Chlorella vulgaris. We followed an array of cellular functions and biomolecules in C. vulgaris cells exposed to 50 or 100 μM Cr at three different initial NH4 (+) concentrations (0.5, 3, and 10 mM). The results showed that Cr strongly inhibited cell yield of C. vulgaris, but 10 mM NH4 (+) could decrease by more than two-fold Cr toxicity on cell yield compared to exposure to 0.5 mM NH4 (+). Cr toxicity on gene transcripts and cellular substructure was also much lower at high than at low NH4 (+). Our results suggest that this protecting effect of NH4 (+) on intracellular Cr toxicity could be due to several factors, such as enhance uptake of phosphorus, increase in C and N assimilation efficiency, and increase transcription of photosynthesis-related genes.
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310027, People's Republic of China.
authors.forename: Jingqing
authors.initials: J
authors.lastname: Liu
authors.forename: Zhengqi
authors.initials: Z
authors.lastname: Sun
authors.forename: Michel
authors.initials: M
authors.lastname: Lavoie
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Fan
authors.forename: Xiaocui
authors.initials: X
authors.lastname: Bai
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qian
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology*; D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D002713:Chlorine / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002857:Chromium / Q000493:pharmacokinetics / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005618:Fresh Water; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects / Q000235:genetics; D013455:Sulfur / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D064751:Ammonium Compounds; D014874:Water Pollutants, Chemical; D002857:Chromium; D002734:Chlorophyll; D010758:Phosphorus; D002713:Chlorine; D013455:Sulfur