| Title: | Enhanced toxicity to the cyanobacterium Microcystis aeruginosa by low-dosage repeated exposure to the allelochemical N-phenyl-1-naphthylamine |
| Author(s): | Gao YN; Ge FJ; Zhang LP; He Y; Lu ZY; Zhang YY; Liu BY; Zhou QH; Wu ZB; |
| Address: | "College of Fisheries, Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang, Henan, 453007, China. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China. Electronic address: qhzhou@ihb.ac.cn" |
| DOI: | 10.1016/j.chemosphere.2017.01.102 |
| ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
| Abstract: | "It has been puzzling whether and how a plant could exert a strong allelopathic inhibition to the target organisms by releasing low concentrations of allelochemicals. Plant allelochemicals have been proposed to be released continuously, however, direct evidence from specific allelochemicals is urgently required. In the present study, the toxicity of allelochemical N-phenyl-1-naphthylamine (NPN) towards the cyanobacterium Microcystis aeruginosa by two different exposure patterns was compared. One was low-dosage repeated exposure (LRE), in which 50 mug L(-1) NPN was repeatedly dosed to simulate the continual release of allelochemicals, and the other one was high-dosage single exposure (HSE) as per the routine toxicity assay. The results showed a significant growth inhibition to M. aeruginosa in the LRE group, where the inhibition rate reached above 90% from day 6 to day 9. The cell-membrane damage ratio increased from 64.05% on day 5 up to 96.60% on day 9. PSII photosynthesis activity expressed as Fv/Fm, Phi(PSII), NPQ and ETRmax was also thoroughly inhibited in this group. Whereas the growth and PSII photosynthesis activity of M. aeruginosa in the HSE group were inhibited initially, but recovered gradually from day 4 or 5, which was accompanied by a continuous reduction of NPN content in culture solutions. Although NPN content in the LRE group was relatively lower, it remained at a more stable level throughout the experiment. These results indicate that continual release of low-dosage allelochemicals by aquatic plants plays crucial roles in their potent inhibition against cyanobacteria. Low-dosage continual exposure pattern needs to be investigated further" |
| Keywords: | "1-Naphthylamine/*analogs & derivatives/toxicity Dose-Response Relationship, Drug Environmental Pollutants/*toxicity Microcystis/*drug effects/growth & development/metabolism Pheromones/*toxicity Photosynthesis/drug effects Time Factors Cell membrane damag;" |
| Notes: | "MedlineGao, Y N Ge, F J Zhang, L P He, Y Lu, Z Y Zhang, Y Y Liu, B Y Zhou, Q H Wu, Z B eng England 2017/02/19 Chemosphere. 2017 May; 174:732-738. doi: 10.1016/j.chemosphere.2017.01.102. Epub 2017 Jan 21" |
