title: Influence of temperature, mixing, and addition of microcystin-LR on microcystin gene expression in Microcystis aeruginosa.
abstract: Cyanobacteria, such as the toxin producer Microcystis aeruginosa, are predicted to be favored by global warming both directly, through elevated water temperatures, and indirectly, through factors such as prolonged stratification of waterbodies. M. aeruginosa is able to produce the hepatotoxin microcystin, which causes great concern in freshwater management worldwide. However, little is known about the expression of microcystin synthesis genes in response to climate change-related factors. In this study, a new RT-qPCR assay employing four reference genes (GAPDH, gltA, rpoC1, and rpoD) was developed to assess the expression of two target genes (the microcystin synthesis genes mcyB and mcyD). This assay was used to investigate changes in mcyB and mcyD expression in response to selected environmental factors associated with global warming. A 10°C rise in temperature significantly increased mcyB expression, but not mcyD expression. Neither mixing nor the addition of microcystin-LR (10 μg L-1or 60 μg L-1) significantly altered mcyB and mcyD expression. The expression levels of mcyB and mcyD were correlated but not identical.
authors.affiliation: Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Department of Ecology and Ecosystem Management, Technical University of Munich, Munich, Germany.
authors.forename: Pia I
authors.identifier: 0000-0002-3998-8875
authors.initials: PI
authors.lastname: Scherer
authors.affiliation: Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Department of Ecology and Ecosystem Management, Technical University of Munich, Munich, Germany.
authors.forename: Uta
authors.initials: U
authors.lastname: Raeder
authors.affiliation: Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Department of Ecology and Ecosystem Management, Technical University of Munich, Munich, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Geist
authors.affiliation: Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Department of Ecology and Ecosystem Management, Technical University of Munich, Munich, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Zwirglmaier
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis* / Q000235:genetics; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics; D057231:Climate Change; D004777:Environment; D004783:Environmental Microbiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D006358:Hot Temperature; D008387:Marine Toxins; D052998:Microcystins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology*; D046931:Microcystis / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological; D014871:Water Microbiology
chemical_list: D018528:ATP-Binding Cassette Transporters; D001427:Bacterial Toxins; D008387:Marine Toxins; C496657:McyH protein, Microcystis aeruginosa; D052998:Microcystins; C078588:microcystin; C057862:cyanoginosin LR
keywords: 
  Microcystis aeruginosa
  ; 
  mcyB
  ; 
  mcyD
  ; 
  qPCR
  ; gene expression; toxic cyanobacteria