Metabolic recovery of the Antarctic liverwort <Emphasis Type="Italic">Cephaloziella varians</Emphasis> during spring snowmelt |
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Authors: | K R S Snell P Convey K K Newsham |
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Institution: | (1) British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK;(2) The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK |
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Abstract: | We measured the responses of pigments and chlorophyll a fluorescence parameters of the Antarctic leafy liverwort Cephaloziella varians to snowmelt during austral spring 2005 at Rothera Point on the western Antarctic Peninsula. Although no changes to the concentrations
of UV-B photoprotective pigments were detected during snowmelt, chlorophyll and carotenoid concentrations and maximum photosystem
(PS)II yield (F
v
/F
m) were respectively 88, 60 and 144% higher in the tissues of the liverwort that had recently emerged from snow than in those
under a 10 cm depth of snow. A laboratory experiment similarly showed that effective PSII yield increased rapidly within the
first 45 min after plants sampled from under snow were removed to an illuminated growth cabinet. The pigmentation and PSII
yields of plants during snowmelt were also compared with those of plants in January, during the middle of the growing season
at Rothera Point. During snowmelt, plants had lower F
v
/F
m values, chlorophyll a/b ratios and concentrations of UV-B photoprotective pigments and carotenoids than during mid-season, suggesting that although
there is some recovery of PSII activity and increases in concentrations of photosynthetic pigments during snowmelt, the metabolism
of C. varians is restricted during this period. |
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Keywords: | Anthocyanin-like pigment Carotenoids Chlorophyll a and b Chlorophyll fluorescence Photosystem II UV-B screening pigments |
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