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Tissue nitrogen status does not alter the physiological responses of Macrocystis pyrifera to ocean acidification

journal contribution
posted on 2023-05-19, 09:43 authored by Fernandez, PA, Roleda, MY, Leal, PP, Hepburn, CD, Catriona HurdCatriona Hurd
Evaluating the relative effects of local (e.g. eutrophication) and global (e.g. ocean acidification, OA) environmental change is important to predict how marine macroalgae might respond to future oceanic conditions. In this study, the effects of nitrate supply, and hence tissue nitrogen status, and OA on the N metabolism, growth and photosynthetic rates of the kelp Macrocystis pyrifera were examined. We hypothesized that (1) NO3 uptake and assimilation processes will depend on nitrate supply and (2) tissue N status modulates the physiological response of Macrocystis to OA. Macrocystis blades were grown for 3 days under replete or deplete NO3 concentrations. Thereafter, the NO3 replete and deplete blades were grown for 3 days under current and future pCO2/pH conditions, with NO3 enriched SW. After the initial pre-experimental incubation, total tissue N content, nitrate reductase (NR) activity and internal NO3 pools were reduced under low [NO3], while NO3 uptake rates increased. Initial tissue N status did not modulate the physiological response to OA. However, NO3 uptake rates and NR activity were enhanced under the OA treatment regardless of the initial tissue N status, suggesting that increases in [H+]/reduced pH might play a regulating role in the N metabolism of this species.

History

Publication title

Marine Biology

Volume

164

Article number

177

Number

177

Pagination

1-14

ISSN

0025-3162

Department/School

Institute for Marine and Antarctic Studies

Publisher

Springer-Verlag

Place of publication

175 Fifth Ave, New York, USA, Ny, 10010

Rights statement

Copyright 2017 Springer-Verlag GmbH Germany

Repository Status

  • Restricted

Socio-economic Objectives

Ecosystem adaptation to climate change

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