Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i>
It has been proposed that ocean acidification (OA) will interact with other environmental factors to influence the overall impact of global change on biological systems. Accordingly we investigated the influence of nitrogen limitation and OA on the physiology of diatoms by growing the diatom <i&g...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-04-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/12/2383/2015/bg-12-2383-2015.pdf |
| _version_ | 1818276344112349184 |
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| author | W. Li K. Gao J. Beardall |
| author_facet | W. Li K. Gao J. Beardall |
| author_sort | W. Li |
| collection | DOAJ |
| description | It has been proposed that ocean acidification (OA) will interact with other
environmental factors to influence the overall impact of global change on
biological systems. Accordingly we investigated the influence of nitrogen
limitation and OA on the physiology of diatoms by growing the diatom
<i>Phaeodactylum tricornutum</i> Bohlin under elevated (1000 μatm; high CO<sub>2</sub> – HC) or ambient (390 μatm; low CO<sub>2</sub> – LC)
levels of CO<sub>2</sub> with replete (110 μmol L<sup>−1</sup>; high nitrate – HN) or reduced
(10 μmol L<sup>−1</sup>; low nitrate – LN) levels of NO<sub>3</sub><sup>-</sup> and subjecting the
cells to solar radiation with or without UV irradiance to determine their
susceptibility to UV radiation (UVR, 280–400 nm). Our results indicate that
OA and UVB induced significantly higher inhibition of both the
photosynthetic rate and quantum yield under LN than under HN conditions. UVA
or/and UVB increased the cells' non-photochemical quenching (NPQ) regardless
of the CO<sub>2</sub> levels. Under LN and OA conditions, activity of superoxide
dismutase and catalase activities were enhanced, along with the highest
sensitivity to UVB and the lowest ratio of repair to damage of PSII.
HC-grown cells showed a faster recovery rate of yield under HN but not under
LN conditions. We conclude therefore that nutrient limitation makes cells
more prone to the deleterious effects of UV radiation and that HC conditions
(ocean acidification) exacerbate this effect. The finding that nitrate
limitation and ocean acidification interact with UV-B to reduce
photosynthetic performance of the diatom <i>P. tricornutum</i> implies that ocean primary
production and the marine biological C pump will be affected by OA under
multiple stressors. |
| first_indexed | 2024-12-12T22:44:09Z |
| format | Article |
| id | doaj.art-fcf570b50b2a4cf9ae79462bcdeccbeb |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-12T22:44:09Z |
| publishDate | 2015-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-fcf570b50b2a4cf9ae79462bcdeccbeb2022-12-22T00:09:15ZengCopernicus PublicationsBiogeosciences1726-41701726-41892015-04-011282383239310.5194/bg-12-2383-2015Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i>W. Li0K. Gao1J. Beardall2State Key Laboratory of Marine Environmental Science, Xiamen University (Xiang'an campus), Xiamen, Fujian, 361102, ChinaState Key Laboratory of Marine Environmental Science, Xiamen University (Xiang'an campus), Xiamen, Fujian, 361102, ChinaSchool of Biological Sciences, Monash University, Clayton, VIC 3800, AustraliaIt has been proposed that ocean acidification (OA) will interact with other environmental factors to influence the overall impact of global change on biological systems. Accordingly we investigated the influence of nitrogen limitation and OA on the physiology of diatoms by growing the diatom <i>Phaeodactylum tricornutum</i> Bohlin under elevated (1000 μatm; high CO<sub>2</sub> – HC) or ambient (390 μatm; low CO<sub>2</sub> – LC) levels of CO<sub>2</sub> with replete (110 μmol L<sup>−1</sup>; high nitrate – HN) or reduced (10 μmol L<sup>−1</sup>; low nitrate – LN) levels of NO<sub>3</sub><sup>-</sup> and subjecting the cells to solar radiation with or without UV irradiance to determine their susceptibility to UV radiation (UVR, 280–400 nm). Our results indicate that OA and UVB induced significantly higher inhibition of both the photosynthetic rate and quantum yield under LN than under HN conditions. UVA or/and UVB increased the cells' non-photochemical quenching (NPQ) regardless of the CO<sub>2</sub> levels. Under LN and OA conditions, activity of superoxide dismutase and catalase activities were enhanced, along with the highest sensitivity to UVB and the lowest ratio of repair to damage of PSII. HC-grown cells showed a faster recovery rate of yield under HN but not under LN conditions. We conclude therefore that nutrient limitation makes cells more prone to the deleterious effects of UV radiation and that HC conditions (ocean acidification) exacerbate this effect. The finding that nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance of the diatom <i>P. tricornutum</i> implies that ocean primary production and the marine biological C pump will be affected by OA under multiple stressors.http://www.biogeosciences.net/12/2383/2015/bg-12-2383-2015.pdf |
| spellingShingle | W. Li K. Gao J. Beardall Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> Biogeosciences |
| title | Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> |
| title_full | Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> |
| title_fullStr | Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> |
| title_full_unstemmed | Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> |
| title_short | Nitrate limitation and ocean acidification interact with UV-B to reduce photosynthetic performance in the diatom <i>Phaeodactylum tricornutum</i> |
| title_sort | nitrate limitation and ocean acidification interact with uv b to reduce photosynthetic performance in the diatom i phaeodactylum tricornutum i |
| url | http://www.biogeosciences.net/12/2383/2015/bg-12-2383-2015.pdf |
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