Saturating light and not increased carbon dioxide under ocean acidification drives photosynthesis and growth in Ulva rigida (Chlorophyta).

ABSTRACT: Carbon physiology of a genetically identified Ulva rigida was investigated under different CO2(aq) and light levels. The study was designed to answer whether (1) light or exogenous inorganic carbon (Ci) pool is driving growth; and (2) elevated CO2(aq) concentration under ocean acidification (OA) will downregulate CAext-mediated [Formula: see text] dehydration and alter the stable carbon isotope (δ (13)C) signatures toward more CO2 use to support higher growth rate. At pHT 9.0 where CO2(aq) is <1 μmol L(-1), inhibition of the known [Formula: see text] use mechanisms, that is, direct [Formula: see text] uptake through the AE port and CAext-mediated [Formula: see text] dehydration decreased net photosynthesis (NPS) by only 56-83%, leaving the carbon uptake mechanism for the remaining 17-44% o

SUBMITTER: Rautenberger R 

PROVIDER: S-EPMC4338970 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature