| Title: | Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia |
| Author(s): | Bojadzija Savic G; Bormans M; Edwards C; Lawton L; Briand E; Wiegand C; |
| Address: | "Univ Rennes 1, CNRS, ECOBIO - UMR 6553, F-35000 Rennes, France. Electronic address: gorenka.bojadzija@gmail.com. Univ Rennes 1, CNRS, ECOBIO - UMR 6553, F-35000 Rennes, France. School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, United Kingdom. Phycotoxins Laboratory, IFREMER, F-44311 Nantes, France" |
| DOI: | 10.1016/j.hal.2020.101803 |
| ISSN/ISBN: | 1878-1470 (Electronic) 1568-9883 (Linking) |
| Abstract: | "Due to eutrophication, freshwater ecosystems frequently experience cyanobacterial blooms, many of which produce bioactive metabolites that can affect vertebrates and invertebrates life traits. Zooplankton are able to develop tolerance as a physiological response to cyanobacteria and their bioactive compounds, however, this comes with energetic cost that in turn influence Daphnia life traits and may impair populations. Vice versa, it has been suggested that Daphnia are able to reduce cyanobacterial dominance until a certain cyanobacterial density; it remains unclear whether Daphnia metabolites alone influence the physiological state and bioactive metabolites production of cyanobacteria. Hence, this study investigates mutual physiological reactions of toxic Microcystis aeruginosa PCC7806 and Daphnia magna. We hypothesize that a) the presence of D. magna will negatively affect growth, increase stress response and metabolites production in M. aeruginosa PCC7806 and b) the presence of M. aeruginosa PCC7806 will negatively affect physiological responses and life traits in D. magna. In order to test these hypotheses experiments were conducted in a specially designed co-culture chamber that allows exchange of the metabolites without direct contact. A clear mutual impact was evidenced. Cyanobacterial metabolites reduced survival of D. magna and decreased oxidative stress enzyme activity. Simultaneously, presence of D. magna did not affect photosynthetic activity. However, ROS increase and tendencies in cell density decrease were observed on the same day, suggesting possible energy allocation towards anti-oxidative stress enzymes, or other protection mechanisms against Daphnia infochemicals, as the strain managed to recover. Elevated concentration of intracellular and overall extracellular microcystin MC-LR, as well as intracellular concentrations of aerucyclamide A and D in the presence of Daphnia, indicating a potential protective or anti-grazing function. However, more research is needed to confirm these findings" |
| Keywords: | Allelopathy Animals *Cyanobacteria Daphnia Ecosystem *Microcystis Cyanobacteria Oxidative stress Pcc7806 Secondary metabolites Toxic Zooplankton; |
| Notes: | "MedlineBojadzija Savic, Gorenka Bormans, Myriam Edwards, Christine Lawton, Linda Briand, Enora Wiegand, Claudia eng Research Support, Non-U.S. Gov't Netherlands 2020/05/18 Harmful Algae. 2020 Apr; 94:101803. doi: 10.1016/j.hal.2020.101803. Epub 2020 Apr 25" |
