title: Photosynthetic and transcriptional responses of the marine diatom Thalassiosira pseudonana to the combined effect of temperature stress and copper exposure.
abstract: A 96-h exposure experiment was conducted to elucidate the toxicity responses of the marine diatom Thalassiosira pseudonana upon exposure to different temperatures and copper (Cu) concentrations. Three Cu treatments (seawater control; 200μg/L Cu, EC50for the yield at 25°C; and 1000μg/L Cu, EC50for growth inhibition at 25°C) were conducted against four temperatures (10°C, 15°C, 25°C and 30°C). Growth rate and photosynthetic responses showed a significant interacting thermal-chemical effect with strong synergistic responses observed at 30°C treatments. Expression of heat shock protein (hsp) was positively modulated by increasing temperatures. Hsp 90, hsp90-2 and sit1 (related to silica shell formation) were highly expressed at 30°C under 1000μg/L Cu, while the genes encoding light harvesting proteins (3HfcpA and 3HfcpB) and silaffin precursor sil3 were significantly up-regulated at 15°C under 200μg/L Cu. Our results indicated an increase Cu toxicity to T. pseudonana under high temperature and Cu dose.
authors.affiliation: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. Electronic address: priscilla_ty_leung@yahoo.com.hk.
authors.forename: Priscilla T Y
authors.initials: PTY
authors.lastname: Leung
authors.affiliation: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Andy Xianliang
authors.initials: AX
authors.lastname: Yi
authors.affiliation: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Jack C H
authors.initials: JCH
authors.lastname: Ip
authors.affiliation: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China; Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Denmark.
authors.forename: Sarah S T
authors.initials: SST
authors.lastname: Mak
authors.affiliation: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. Electronic address: kmyleung@hku.hk.
authors.forename: Kenneth M Y
authors.initials: KMY
authors.lastname: Leung
mesh_terms: D003300:Copper / Q000009:adverse effects*; D017377:Diatoms / Q000187:drug effects / Q000502:physiology*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D006358:Hot Temperature / Q000009:adverse effects*; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology*; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics*; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper
keywords: Copper; Heat shock protein; Marine diatom; Photosynthesis; Thalassiosira; Thermal stress