Induction of Inorganic Carbon Accumulation in the Unicellular Green Algae Scenedesmus obliquus and Chlamydomonas reinhardtii1
AUTOR(ES)
Palmqvist, Kristin
RESUMO
The induction of a dissolved inorganic carbon (DIC) accumulating mechanism in the two algal species Scenedesmus obliquus (WT) and Chlamydomonas reinhardtii (137 c+) was physiologically characterized by monitoring DIC uptake kinetics at a low and constant DIC concentration (120-140 micromolar), after transfer from high-DIC culturing conditions. A potentiometric titration method was used to measure and calculate algal DIC uptake. Full acclimation to low-DIC conditions was obtained within a period of 90 min, after which time the DIC uptake had been increased 7 to 10 times. Experiments were also conducted in the presence of inhibitors against DIC accumulation. The inhibitor of extracellular carbonic anhydrase (CA), acetazolamide (50 micromolar), inhibited the adaptation partly, while the inhibitor of both extra- and intracellular CA, ethoxyzolamide (50 micromolar) totally inhibited the acclimation. Cycloheximide (10 micrograms per milliliter), which inhibits protein synthesis on cytoplasmic ribosomes, and vanadate (180 micromolar), which inhibits the plasmamembrane bound ATPase, also inhibited the acclimation totally. These results taken together suggest that the algae are dependent on intracellular CA, plasmamembrane bound ATPase, and de novo protein synthesis for DIC accumulation. Also, these components are more important than extracellular CA for the overall function of the DIC-accumulating mechanism.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1054770Documentos Relacionados
- Evidence for Inorganic Carbon Transport by Intact Chloroplasts of Chlamydomonas reinhardtii1
- The Involvement of a Multicopper Oxidase in Iron Uptake by the Green Algae Chlamydomonas reinhardtii1
- Regulation by Polyamines of Ornithine Decarboxylase Activity and Cell Division in the Unicellular Green Alga Chlamydomonas reinhardtii1
- Intracellular Carbon Partitioning in Chlamydomonas reinhardtii1
- Active CO2 Transport by the Green Alga Chlamydomonas reinhardtii1