Antarctic microalgae: physiological acclimation to environmental change
Sea ice algal communities play a very significant role in primary production in the Southern Ocean, being the only source of fixed carbon for all other life in this habitat and contributing up to 22% of Antarctic primary production in ice-covered regions. Therefore it is important to understand how...
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ftvictoriauwfig:oai:figshare.com:article/17008204 2023-05-15T13:35:14+02:00 Antarctic microalgae: physiological acclimation to environmental change Rajanahally, Meghana Amarnath 2014-01-01T00:00:00Z https://doi.org/10.26686/wgtn.17008204.v1 https://figshare.com/articles/thesis/Antarctic_microalgae_physiological_acclimation_to_environmental_change/17008204 unknown doi:10.26686/wgtn.17008204.v1 https://figshare.com/articles/thesis/Antarctic_microalgae_physiological_acclimation_to_environmental_change/17008204 Author Retains Copyright Phycology (incl. Marine Grasses) Antarctica Algae Sea ice School: School of Biological Sciences 060701 Phycology (incl. Marine Grasses) 960808 Marine Flora Fauna and Biodiversity 970106 Expanding Knowledge in the Biological Sciences Degree Discipline: Marine Biology Degree Level: Masters Degree Name: Master of Science Text Thesis 2014 ftvictoriauwfig https://doi.org/10.26686/wgtn.17008204.v1 2021-11-18T00:05:21Z Sea ice algal communities play a very significant role in primary production in the Southern Ocean, being the only source of fixed carbon for all other life in this habitat and contributing up to 22% of Antarctic primary production in ice-covered regions. Therefore it is important to understand how these organisms adapt to this highly variable and harsh environment Previous studies have described their acclimation to changes in environmental conditions but we still do not understand the physiological basis of these responses. This study examines the effects of varying levels of photosynthetically active radiation (PAR), ultraviolet-B (UV-B) radiation and temperature on bottom ice algal communities and individual algal species using pulse-amplitude modulation (PAM) fluorometry, the production of mycosporine-like amino acids (MAAs) and superoxide dismutase (SOD) activity. The experiments conducted in this thesis show that bottom ice algae are capable of acclimating to the higher levels of PAR and temperature that would likely be experienced during sea ice melt As temperature was increased past a threshold temperature of thylakoid integrity, it became the major stressor, causing decreases in photosynthetic yield at around 14°C, even at ambient PAR exposure. Similarly, a thylakoid integrity experiment independently suggested that the critical temperature for the onset of thylakoid damage was 14°C, which correlated well to the 14°C incubation observations, although this is a temperature that sea ice algae are unlikely to encounter in the polar regions. It is likely that sea ice algae produce additional MAAs, known to be cellular sunscreens, in response to increasing levels of UV-B, allowing tolerance of this stressor. This is the first study in the marine environment to demonstrate that algae can produce MAAs in response to increasing PAR and temperature, even in the absence of UV-B, indicating that MAAs may be more than just sunscreen compounds. The levels of UV-B used in this study were representative of those ... Thesis Antarc* Antarctic Antarctica ice algae Sea ice Southern Ocean Open Access Victoria University of Wellington / Te Herenga Waka Antarctic Southern Ocean |
institution |
Open Polar |
collection |
Open Access Victoria University of Wellington / Te Herenga Waka |
op_collection_id |
ftvictoriauwfig |
language |
unknown |
topic |
Phycology (incl. Marine Grasses) Antarctica Algae Sea ice School: School of Biological Sciences 060701 Phycology (incl. Marine Grasses) 960808 Marine Flora Fauna and Biodiversity 970106 Expanding Knowledge in the Biological Sciences Degree Discipline: Marine Biology Degree Level: Masters Degree Name: Master of Science |
spellingShingle |
Phycology (incl. Marine Grasses) Antarctica Algae Sea ice School: School of Biological Sciences 060701 Phycology (incl. Marine Grasses) 960808 Marine Flora Fauna and Biodiversity 970106 Expanding Knowledge in the Biological Sciences Degree Discipline: Marine Biology Degree Level: Masters Degree Name: Master of Science Rajanahally, Meghana Amarnath Antarctic microalgae: physiological acclimation to environmental change |
topic_facet |
Phycology (incl. Marine Grasses) Antarctica Algae Sea ice School: School of Biological Sciences 060701 Phycology (incl. Marine Grasses) 960808 Marine Flora Fauna and Biodiversity 970106 Expanding Knowledge in the Biological Sciences Degree Discipline: Marine Biology Degree Level: Masters Degree Name: Master of Science |
description |
Sea ice algal communities play a very significant role in primary production in the Southern Ocean, being the only source of fixed carbon for all other life in this habitat and contributing up to 22% of Antarctic primary production in ice-covered regions. Therefore it is important to understand how these organisms adapt to this highly variable and harsh environment Previous studies have described their acclimation to changes in environmental conditions but we still do not understand the physiological basis of these responses. This study examines the effects of varying levels of photosynthetically active radiation (PAR), ultraviolet-B (UV-B) radiation and temperature on bottom ice algal communities and individual algal species using pulse-amplitude modulation (PAM) fluorometry, the production of mycosporine-like amino acids (MAAs) and superoxide dismutase (SOD) activity. The experiments conducted in this thesis show that bottom ice algae are capable of acclimating to the higher levels of PAR and temperature that would likely be experienced during sea ice melt As temperature was increased past a threshold temperature of thylakoid integrity, it became the major stressor, causing decreases in photosynthetic yield at around 14°C, even at ambient PAR exposure. Similarly, a thylakoid integrity experiment independently suggested that the critical temperature for the onset of thylakoid damage was 14°C, which correlated well to the 14°C incubation observations, although this is a temperature that sea ice algae are unlikely to encounter in the polar regions. It is likely that sea ice algae produce additional MAAs, known to be cellular sunscreens, in response to increasing levels of UV-B, allowing tolerance of this stressor. This is the first study in the marine environment to demonstrate that algae can produce MAAs in response to increasing PAR and temperature, even in the absence of UV-B, indicating that MAAs may be more than just sunscreen compounds. The levels of UV-B used in this study were representative of those ... |
format |
Thesis |
author |
Rajanahally, Meghana Amarnath |
author_facet |
Rajanahally, Meghana Amarnath |
author_sort |
Rajanahally, Meghana Amarnath |
title |
Antarctic microalgae: physiological acclimation to environmental change |
title_short |
Antarctic microalgae: physiological acclimation to environmental change |
title_full |
Antarctic microalgae: physiological acclimation to environmental change |
title_fullStr |
Antarctic microalgae: physiological acclimation to environmental change |
title_full_unstemmed |
Antarctic microalgae: physiological acclimation to environmental change |
title_sort |
antarctic microalgae: physiological acclimation to environmental change |
publishDate |
2014 |
url |
https://doi.org/10.26686/wgtn.17008204.v1 https://figshare.com/articles/thesis/Antarctic_microalgae_physiological_acclimation_to_environmental_change/17008204 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctica ice algae Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica ice algae Sea ice Southern Ocean |
op_relation |
doi:10.26686/wgtn.17008204.v1 https://figshare.com/articles/thesis/Antarctic_microalgae_physiological_acclimation_to_environmental_change/17008204 |
op_rights |
Author Retains Copyright |
op_doi |
https://doi.org/10.26686/wgtn.17008204.v1 |
_version_ |
1766063219805257728 |