Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions
Ocean acidification (OA), the ongoing decline in seawater pH, is predicted to have wide-ranging effects on marine organisms and ecosystems. For seaweeds, the pH at the thallus surface, within the diffusion boundary layer (DBL), is one of the factors controlling their response to OA. Surface pH is co...
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Online Access: | https://eprints.utas.edu.au/38953/ http://dx.doi.org/oi:10.1111/ppl.12478 |
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ftunivtasmania:oai:eprints.utas.edu.au:38953 2023-05-15T17:50:43+02:00 Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions Fernandez, PA Roleda, MY Leal, PP Hurd, CL 2017 https://eprints.utas.edu.au/38953/ http://dx.doi.org/oi:10.1111/ppl.12478 unknown Blackwell Munksgaard Fernandez, PA, Roleda, MY, Leal, PP and Hurd, CL orcid:0000-0001-9965-4917 2017 , 'Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions' , Physiologia Plantarum, vol. 159, no. 1 , pp. 107-119 , doi:10.1111/ppl.12478 <http://dx.doi.org/10.1111/ppl.12478>. Macrocystis kelp ocean acidification nitrogen climate change Article PeerReviewed 2017 ftunivtasmania https://doi.org/10.1111/ppl.12478 2021-12-13T23:18:00Z Ocean acidification (OA), the ongoing decline in seawater pH, is predicted to have wide-ranging effects on marine organisms and ecosystems. For seaweeds, the pH at the thallus surface, within the diffusion boundary layer (DBL), is one of the factors controlling their response to OA. Surface pH is controlled by both the pH of the bulk seawater and by the seaweeds’ metabolism: photosynthesis and respiration increase and decrease pH within the DBL (pHDBL), respectively. However, other metabolic processes, especially the uptake of inorganic nitrogen (Ni; NO3− and NH4+) may also affect the pHDBL. Using Macrocystis pyrifera, we hypothesized that (1) NO3− uptake will increase the pHDBL, whereas NH4+ uptake will decrease it, (2) if NO3− is cotransported with H+, increases in pHDBL would be greater under an OA treatment (pH = 7.65) than under an ambient treatment (pH = 8.00), and (3) decreases in pHDBL will be smaller at pH 7.65 than at pH 8.00, as higher external [H+] might affect the strength of the diffusion gradient. Overall, Ni source did not affect the pHDBL. However, increases in pHDBL were greater at pH 7.65 than at pH 8.00. CO2 uptake was higher at pH 7.65 than at pH 8.00, whereas HCO3− uptake was unaffected by pH. Photosynthesis and respiration control pHDBL rather than Ni uptake. We suggest that under future OA, Macrocystis pyrifera will metabolically modify its surface microenvironment such that the physiological processes of photosynthesis and Ni uptake will not be affected by a reduced pH. Article in Journal/Newspaper Ocean acidification University of Tasmania: UTas ePrints Physiologia Plantarum 159 1 107 119 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
unknown |
topic |
Macrocystis kelp ocean acidification nitrogen climate change |
spellingShingle |
Macrocystis kelp ocean acidification nitrogen climate change Fernandez, PA Roleda, MY Leal, PP Hurd, CL Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
topic_facet |
Macrocystis kelp ocean acidification nitrogen climate change |
description |
Ocean acidification (OA), the ongoing decline in seawater pH, is predicted to have wide-ranging effects on marine organisms and ecosystems. For seaweeds, the pH at the thallus surface, within the diffusion boundary layer (DBL), is one of the factors controlling their response to OA. Surface pH is controlled by both the pH of the bulk seawater and by the seaweeds’ metabolism: photosynthesis and respiration increase and decrease pH within the DBL (pHDBL), respectively. However, other metabolic processes, especially the uptake of inorganic nitrogen (Ni; NO3− and NH4+) may also affect the pHDBL. Using Macrocystis pyrifera, we hypothesized that (1) NO3− uptake will increase the pHDBL, whereas NH4+ uptake will decrease it, (2) if NO3− is cotransported with H+, increases in pHDBL would be greater under an OA treatment (pH = 7.65) than under an ambient treatment (pH = 8.00), and (3) decreases in pHDBL will be smaller at pH 7.65 than at pH 8.00, as higher external [H+] might affect the strength of the diffusion gradient. Overall, Ni source did not affect the pHDBL. However, increases in pHDBL were greater at pH 7.65 than at pH 8.00. CO2 uptake was higher at pH 7.65 than at pH 8.00, whereas HCO3− uptake was unaffected by pH. Photosynthesis and respiration control pHDBL rather than Ni uptake. We suggest that under future OA, Macrocystis pyrifera will metabolically modify its surface microenvironment such that the physiological processes of photosynthesis and Ni uptake will not be affected by a reduced pH. |
format |
Article in Journal/Newspaper |
author |
Fernandez, PA Roleda, MY Leal, PP Hurd, CL |
author_facet |
Fernandez, PA Roleda, MY Leal, PP Hurd, CL |
author_sort |
Fernandez, PA |
title |
Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
title_short |
Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
title_full |
Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
title_fullStr |
Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
title_full_unstemmed |
Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
title_sort |
seawater ph, and not inorganic nitrogen source, affects ph at the blade surface of macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions |
publisher |
Blackwell Munksgaard |
publishDate |
2017 |
url |
https://eprints.utas.edu.au/38953/ http://dx.doi.org/oi:10.1111/ppl.12478 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
Fernandez, PA, Roleda, MY, Leal, PP and Hurd, CL orcid:0000-0001-9965-4917 2017 , 'Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions' , Physiologia Plantarum, vol. 159, no. 1 , pp. 107-119 , doi:10.1111/ppl.12478 <http://dx.doi.org/10.1111/ppl.12478>. |
op_doi |
https://doi.org/10.1111/ppl.12478 |
container_title |
Physiologia Plantarum |
container_volume |
159 |
container_issue |
1 |
container_start_page |
107 |
op_container_end_page |
119 |
_version_ |
1766157589832269824 |