Physiological plasticity related to zonation affects hsp70 expression in the reef-building coral Pocillopora verrucosa

PLoS One. 2017 Feb 15;12(2):e0171456. doi: 10.1371/journal.pone.0171456. eCollection 2017.

Abstract

This study investigates for the first time the transcriptional regulation of a stress-inducible 70-kDa heat shock protein (hsp70) in the scleractinian coral Pocillopora verrucosa sampled at three locations and two depths (3 m and 12 m) in Bangka Island waters (North Sulawesi, Indonesia). Percentage of coral cover indicated reduced habitat suitability with depth and at the Tanjung Husi (TA) site, which also displayed relatively higher seawater temperatures. Expression of the P. verrucosa hsp70 transcript evaluated under field conditions followed a depth-related profile, with relatively higher expression levels in 3-m collected nubbins compared to the 12-m ones. Expression levels of metabolism-related transcripts ATP synthase and NADH dehydrogenase indicated metabolic activation of nubbins to cope with habitat conditions of the TA site at 3 m. After a 14-day acclimatization to common and fixed temperature conditions in the laboratory, corals were subjected for 7 days to an altered thermal regime, where temperature was elevated at 31°C during the light phase and returned to 28°C during the dark phase. Nubbins collected at 12 m were relatively more sensitive to thermal stress, as they significantly over-expressed the selected transcripts. Corals collected at 3 m appeared more resilient, as they showed unaffected mRNA expressions. The results indicated that local habitat conditions may influence transcription of stress-related genes in P. verrucosa. Corals exhibiting higher basal hsp70 levels may display enhanced tolerance towards environmental stressors.

MeSH terms

  • ATP Synthetase Complexes / genetics
  • ATP Synthetase Complexes / metabolism
  • Acclimatization
  • Animals
  • Anthozoa / genetics*
  • Anthozoa / metabolism*
  • Anthozoa / radiation effects
  • Coral Reefs
  • Gene Expression Regulation*
  • HSP70 Heat-Shock Proteins / genetics*
  • HSP70 Heat-Shock Proteins / metabolism
  • Light
  • NADH Dehydrogenase / genetics
  • NADH Dehydrogenase / metabolism
  • Principal Component Analysis
  • RNA / isolation & purification
  • RNA / metabolism
  • RNA, Messenger / metabolism
  • Real-Time Polymerase Chain Reaction
  • Temperature
  • Transcriptome / radiation effects

Substances

  • HSP70 Heat-Shock Proteins
  • RNA, Messenger
  • RNA
  • NADH Dehydrogenase
  • ATP Synthetase Complexes

Grants and funding

Support was provided by the Italian Ministry of University and Research (MIUR - RFO2013) to EF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.