Response of the seagrass Posidonia oceanica and its associated N2 fixers to high business-as-usual climate change scenario in winter
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Response of the seagrass Posidonia oceanica and its associated N2 fixers to high business-as-usual climate change scenario in winter. / Agawin, N.S.R.; Gil Atorrasagasti, M.G.; Frank Comas, A.; Fernández-Juárez, V.; López-Alforja, X.; Hendriks, I.E.
I: Limnology and Oceanography, Bind 66, Nr. 6, 2021.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Response of the seagrass Posidonia oceanica and its associated N2 fixers to high business-as-usual climate change scenario in winter
AU - Agawin, N.S.R.
AU - Gil Atorrasagasti, M.G.
AU - Frank Comas, A.
AU - Fernández-Juárez, V.
AU - López-Alforja, X.
AU - Hendriks, I.E.
PY - 2021
Y1 - 2021
N2 - We investigated the effects of increasing seawater temperature and CO2 concentration based on a high business-as-usual climate change scenario by year 2100 on the photosynthetic performance and productivity of Mediterranean seagrass Posidonia oceanica and alkaline phosphatase and N2-fixing activities of microbes associated with different plant parts during winter when the plants may be thermally more vulnerable. Our results suggest that elevated CO2 and temperature benefit the overall photosynthetic performance of P. oceanica. Despite the benefits, the magnitude of respiration increased with elevated CO2 resulting in a negative carbon balance for P. oceanica in winter. This trend is contradictory to the general notion of decreased respiration in plants with increasing CO2, and warrants future investigation on the mechanisms behind the opposite trend. Changes of alkaline phosphatase activities found here may not be a direct consequence of the different treatments, but indirectly, through changes in the demand for dissolved inorganic phosphorus for N2 fixers. Of the several groups of N2 fixers tested for nifH expression (a proxy for activity of nitrogenase, the enzyme required for N2 fixation), only the unicellular N2-fixing cyanobacterial phylotypes, UCYNB and UCYNC, actively transcribed with a positive nifH transcription response of UCYNC to elevated CO2 and temperature. Our results suggest that in future climate scenarios, the structure and diversity of N2 microbial communities associated with seagrasses may change and high-light the importance of investigating the responses of different groups individually in their natural habitat substrates.
AB - We investigated the effects of increasing seawater temperature and CO2 concentration based on a high business-as-usual climate change scenario by year 2100 on the photosynthetic performance and productivity of Mediterranean seagrass Posidonia oceanica and alkaline phosphatase and N2-fixing activities of microbes associated with different plant parts during winter when the plants may be thermally more vulnerable. Our results suggest that elevated CO2 and temperature benefit the overall photosynthetic performance of P. oceanica. Despite the benefits, the magnitude of respiration increased with elevated CO2 resulting in a negative carbon balance for P. oceanica in winter. This trend is contradictory to the general notion of decreased respiration in plants with increasing CO2, and warrants future investigation on the mechanisms behind the opposite trend. Changes of alkaline phosphatase activities found here may not be a direct consequence of the different treatments, but indirectly, through changes in the demand for dissolved inorganic phosphorus for N2 fixers. Of the several groups of N2 fixers tested for nifH expression (a proxy for activity of nitrogenase, the enzyme required for N2 fixation), only the unicellular N2-fixing cyanobacterial phylotypes, UCYNB and UCYNC, actively transcribed with a positive nifH transcription response of UCYNC to elevated CO2 and temperature. Our results suggest that in future climate scenarios, the structure and diversity of N2 microbial communities associated with seagrasses may change and high-light the importance of investigating the responses of different groups individually in their natural habitat substrates.
U2 - 10.1002/lno.11758
DO - 10.1002/lno.11758
M3 - Tidsskriftartikel
VL - 66
JO - Limnology and Oceanography
JF - Limnology and Oceanography
SN - 0024-3590
IS - 6
ER -
ID: 337347606