Blog
About

7
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Intracellular pH and its response to CO2-driven seawater acidification in symbiotic versus non-symbiotic coral cells.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Regulating intracellular pH (pHi) is critical for optimising the metabolic activity of corals, yet the mechanisms involved in pH regulation and the buffering capacity within coral cells are not well understood. Our study investigated how the presence of symbiotic dinoflagellates affects the response of pHi to PCO2-driven seawater acidification in cells isolated from Pocillopora damicornis. Using the fluorescent dye BCECF-AM, in conjunction with confocal microscopy, we simultaneously characterised the pHi response in host coral cells and their dinoflagellate symbionts, in symbiotic and non-symbiotic states under saturating light, with and without the photosynthetic inhibitor DCMU. Each treatment was run under control (pH 7.8) and CO2-acidified seawater conditions (decreasing pH from 7.8 to 6.8). After 105 min of CO2 addition, by which time the external pH (pHe) had declined to 6.8, the dinoflagellate symbionts had increased their pHi by 0.5 pH units above control levels when in the absence of DCMU. In contrast, in both symbiotic and non-symbiotic host coral cells, 15 min of CO2 addition (0.2 pH unit drop in pHe) led to cytoplasmic acidosis equivalent to 0.3-0.4 pH units irrespective of whether DCMU was present. Despite further seawater acidification over the duration of the experiment, the pHi of non-symbiotic coral cells did not change, though in host cells containing a symbiont cell the pHi recovered to control levels when photsynthesis was not inhibited. This recovery was negated when cells were incubated with DCMU. Our results reveal that photosynthetic activity of the endosymbiont is tightly coupled with the ability of the host cell to recover from cellular acidosis after exposure to high CO2/low pH.

          Related collections

          Author and article information

          Journal
          J. Exp. Biol.
          The Journal of experimental biology
          1477-9145
          0022-0949
          Jun 1 2014
          : 217
          : Pt 11
          Affiliations
          [1 ] School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New Zealand.
          [2 ] Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1346, Kaneohe, HI 96744, USA.
          [3 ] School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New Zealand simon.davy@vuw.ac.nz.
          Article
          jeb.099549
          10.1242/jeb.099549
          24625648
          © 2014. Published by The Company of Biologists Ltd.

          Symbiodinium, Climate change, Acidosis

          Comments

          Comment on this article