Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability
<p><i>Skeletonema costatum</i> is a common bloom-forming diatom and encounters eutrophication and severe carbon dioxide (CO<sub>2</sub>) limitation during red tides. However, little is known regarding the role of phosphorus (P) in modulating inorganic carbon acquisit...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-08-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/4871/2018/bg-15-4871-2018.pdf |
| _version_ | 1818154174629543936 |
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| author | G. Gao G. Gao G. Gao J. Xia J. Yu J. Fan X. Zeng |
| author_facet | G. Gao G. Gao G. Gao J. Xia J. Yu J. Fan X. Zeng |
| author_sort | G. Gao |
| collection | DOAJ |
| description | <p><i>Skeletonema costatum</i> is a common bloom-forming diatom and encounters
eutrophication and severe carbon dioxide (CO<sub>2</sub>) limitation during red
tides. However, little is known regarding the role of phosphorus (P) in
modulating inorganic carbon acquisition in <i>S. costatum</i>, particularly
under CO<sub>2</sub> limitation conditions. We cultured <i>S. costatum</i> under
five phosphate levels (0.05, 0.25, 1, 4, 10 µmol L<sup>−1</sup>) and then
treated it with two CO<sub>2</sub> conditions (2.8 and 12.6 µmol L<sup>−1</sup>)
for 2 h. The lower CO<sub>2</sub> reduced net photosynthetic rate at lower
phosphate levels (< 4 µmol L<sup>−1</sup>) but did not affect it at
higher phosphate levels (4 and 10 µmol L<sup>−1</sup>). In contrast, the lower
CO<sub>2</sub> induced a higher dark respiration rate at lower phosphate levels (0.05
and 0.25 µmol L<sup>−1</sup>) and did not affect it at higher phosphate levels
(> 1 µmol L<sup>−1</sup>). The lower CO<sub>2</sub> did not change
relative electron transport rate (rETR) at lower phosphate levels (0.05 and
0.25 µmol L<sup>−1</sup>) and increased it at higher phosphate levels
(> 1 µmol L<sup>−1</sup>). Photosynthetic CO<sub>2</sub> affinity
(1/<i>K</i><sub>0.5</sub>) increased with phosphate levels. The lower CO<sub>2</sub> did not
affect photosynthetic CO<sub>2</sub> affinity at 0.05 µmol L<sup>−1</sup> phosphate but enhanced it at the other phosphate levels. Activity of
extracellular carbonic anhydrase was dramatically induced by the lower
CO<sub>2</sub> in phosphate-replete conditions (> 0.25 µmol L<sup>−1</sup>) and the same pattern also occurred for redox activity of the plasma
membrane. Direct bicarbonate (HCO<sub>3</sub><sup>−</sup>) use was induced when phosphate
concentration was more than 1 µmol L<sup>−1</sup>. These findings indicate P
enrichment could enhance inorganic carbon acquisition and thus maintain the
photosynthesis rate in <i>S. costatum</i> grown under CO<sub>2</sub>-limiting
conditions via increasing activity of extracellular carbonic anhydrase and
facilitating direct HCO<sub>3</sub><sup>−</sup> use. This study sheds light on how
bloom-forming algae cope with carbon limitation during the development of red
tides.</p> |
| first_indexed | 2024-12-11T14:22:19Z |
| format | Article |
| id | doaj.art-ac3d52dcfdea44ba9e8727bc7fccd40d |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-11T14:22:19Z |
| publishDate | 2018-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-ac3d52dcfdea44ba9e8727bc7fccd40d2022-12-22T01:02:51ZengCopernicus PublicationsBiogeosciences1726-41701726-41892018-08-01154871488210.5194/bg-15-4871-2018Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availabilityG. Gao0G. Gao1G. Gao2J. Xia3J. Yu4J. Fan5X. Zeng6School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, ChinaJiangsu Key Laboratory of Marine Bioresources and Environment, Huaihai Institute of Technology, Lianyungang, 222005, ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, ChinaSchool of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, ChinaSchool of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, ChinaJiangsu Key Laboratory of Marine Bioresources and Environment, Huaihai Institute of Technology, Lianyungang, 222005, ChinaSchool of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China<p><i>Skeletonema costatum</i> is a common bloom-forming diatom and encounters eutrophication and severe carbon dioxide (CO<sub>2</sub>) limitation during red tides. However, little is known regarding the role of phosphorus (P) in modulating inorganic carbon acquisition in <i>S. costatum</i>, particularly under CO<sub>2</sub> limitation conditions. We cultured <i>S. costatum</i> under five phosphate levels (0.05, 0.25, 1, 4, 10 µmol L<sup>−1</sup>) and then treated it with two CO<sub>2</sub> conditions (2.8 and 12.6 µmol L<sup>−1</sup>) for 2 h. The lower CO<sub>2</sub> reduced net photosynthetic rate at lower phosphate levels (< 4 µmol L<sup>−1</sup>) but did not affect it at higher phosphate levels (4 and 10 µmol L<sup>−1</sup>). In contrast, the lower CO<sub>2</sub> induced a higher dark respiration rate at lower phosphate levels (0.05 and 0.25 µmol L<sup>−1</sup>) and did not affect it at higher phosphate levels (> 1 µmol L<sup>−1</sup>). The lower CO<sub>2</sub> did not change relative electron transport rate (rETR) at lower phosphate levels (0.05 and 0.25 µmol L<sup>−1</sup>) and increased it at higher phosphate levels (> 1 µmol L<sup>−1</sup>). Photosynthetic CO<sub>2</sub> affinity (1/<i>K</i><sub>0.5</sub>) increased with phosphate levels. The lower CO<sub>2</sub> did not affect photosynthetic CO<sub>2</sub> affinity at 0.05 µmol L<sup>−1</sup> phosphate but enhanced it at the other phosphate levels. Activity of extracellular carbonic anhydrase was dramatically induced by the lower CO<sub>2</sub> in phosphate-replete conditions (> 0.25 µmol L<sup>−1</sup>) and the same pattern also occurred for redox activity of the plasma membrane. Direct bicarbonate (HCO<sub>3</sub><sup>−</sup>) use was induced when phosphate concentration was more than 1 µmol L<sup>−1</sup>. These findings indicate P enrichment could enhance inorganic carbon acquisition and thus maintain the photosynthesis rate in <i>S. costatum</i> grown under CO<sub>2</sub>-limiting conditions via increasing activity of extracellular carbonic anhydrase and facilitating direct HCO<sub>3</sub><sup>−</sup> use. This study sheds light on how bloom-forming algae cope with carbon limitation during the development of red tides.</p>https://www.biogeosciences.net/15/4871/2018/bg-15-4871-2018.pdf |
| spellingShingle | G. Gao G. Gao G. Gao J. Xia J. Yu J. Fan X. Zeng Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability Biogeosciences |
| title | Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability |
| title_full | Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability |
| title_fullStr | Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability |
| title_full_unstemmed | Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability |
| title_short | Regulation of inorganic carbon acquisition in a red tide alga (<i>Skeletonema costatum</i>): the importance of phosphorus availability |
| title_sort | regulation of inorganic carbon acquisition in a red tide alga i skeletonema costatum i the importance of phosphorus availability |
| url | https://www.biogeosciences.net/15/4871/2018/bg-15-4871-2018.pdf |
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