Species-specific influence of P-i-status on inorganic carbon acquisition in microalgae (Chlorophyceae)
- Inorganic phosphorus (P-i) is often the primary limiting nutrient in freshwater ecosystems. Since P(i-)limitation affects energy transduction, and inorganic carbon (C-i) acquisition can be energy demanding, C(i-)acquisition strategies were compared in four species of green algae grown under P-i-replete and P-i-limited conditions predominantly at low and partly at high CO2. Although P-i-limitation was evident by the 10-fold higher cellular C:P ratio and enhanced phosphatase activity, it only decreased C-i-acquisition to a small extent. Nonetheless, the effects of Pi-limitation on both CO2 and HCO3- acquisition were demonstrated. Decreased CO2 acquisition under conditions of Pi limitation was mainly visible in the maximum uptake rate (V-max) and, for the neutrophile Scenedesmus vacuolatus, in the affinity for CO2 acquisition. Discrimination against C-13 was higher under P-i-limited, high CO2 conditions, compared with P-i-replete, highCO(2) conditions, in Chlamydomonas acidophila and S. vacuolatus. In the pH-drift experiments, HCO3-Inorganic phosphorus (P-i) is often the primary limiting nutrient in freshwater ecosystems. Since P(i-)limitation affects energy transduction, and inorganic carbon (C-i) acquisition can be energy demanding, C(i-)acquisition strategies were compared in four species of green algae grown under P-i-replete and P-i-limited conditions predominantly at low and partly at high CO2. Although P-i-limitation was evident by the 10-fold higher cellular C:P ratio and enhanced phosphatase activity, it only decreased C-i-acquisition to a small extent. Nonetheless, the effects of Pi-limitation on both CO2 and HCO3- acquisition were demonstrated. Decreased CO2 acquisition under conditions of Pi limitation was mainly visible in the maximum uptake rate (V-max) and, for the neutrophile Scenedesmus vacuolatus, in the affinity for CO2 acquisition. Discrimination against C-13 was higher under P-i-limited, high CO2 conditions, compared with P-i-replete, highCO(2) conditions, in Chlamydomonas acidophila and S. vacuolatus. In the pH-drift experiments, HCO3- acquisition was reduced in P-i-limited C. reinhardtii. In general, energy demanding bicarbonate uptake was indicated by the less strong discrimination against (13)Cunder lowCO(2) conditions in the neutrophiles (HCO3- users), separating them from the acidophilic or acidotolerant species (CO2 users). The high variability of the influence of Pi supply among different green algal species is linked to their species-specific C(i-)acquisition strategies.…
Author details: | Sabrina C. LachmannORCiDGND, Stephen C. Maberly, Elly SpijkermanORCiD |
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DOI: | https://doi.org/10.1139/cjb-2017-0082 |
ISSN: | 1916-2790 |
ISSN: | 1916-2804 |
Title of parent work (English): | Botany |
Publisher: | NRC Research Press |
Place of publishing: | Ottawa |
Publication type: | Article |
Language: | English |
Year of first publication: | 2017 |
Publication year: | 2017 |
Release date: | 2020/04/20 |
Tag: | CCM; Chlamydomonas; inorganic carbon uptake kinetics; inorganic phosphorus limitation; stable carbon isotope discrimination |
Volume: | 95 |
Number of pages: | 10 |
First page: | 943 |
Last Page: | 952 |
Funding institution: | German Research Foundation [SP695/5-1]; UK Natural Environment Research Council |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
Peer review: | Referiert |