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Full-Text Articles in Social and Behavioral Sciences
Cell Wall-Bound Ultraviolet-Screening Compounds Explain The High Ultraviolet Tolerance Of The Antarctic Moss, Ceratodon Purpureus, L. J. Clarke, Sharon A. Robinson
Cell Wall-Bound Ultraviolet-Screening Compounds Explain The High Ultraviolet Tolerance Of The Antarctic Moss, Ceratodon Purpureus, L. J. Clarke, Sharon A. Robinson
Faculty of Science - Papers (Archive)
Studies of ultraviolet (UV) light-induced DNA damage in three Antarctic moss species have shown Ceratodon purpureus to be the most UV tolerant, despite containing lower concentrations of methanol-soluble UV-screening compounds than the co-occurring Bryum pseudotriquetrum. In this study, alkali extraction of cell wall-bound phenolics, combined with methanol extraction of soluble phenolics, was used to determine whether cell wall-bound UV screens explain the greater UV tolerance of C. purpureus. The combined pool of UV screens was similar in B. pseudotriquetrum and C. purpureus, but whilst B. pseudotriquetrum had almost equal concentrations of MeOH-soluble and alkali-extractable cell wall-bound UV-screening compounds, in C. …
Somatic Mutation And The Antarctic Ozone Hole, L. J. Clarke, Sharon A. Robinson, D. J. Ayre
Somatic Mutation And The Antarctic Ozone Hole, L. J. Clarke, Sharon A. Robinson, D. J. Ayre
Faculty of Science - Papers (Archive)
1 Previous studies of Antarctic clonal moss populations using RAPD markers have reported extraordinarily high levels of genetic variation. This has been claimed to reflect somatic mutation, possibly resulting from elevated UV-B radiation. 2 Our study used microsatellite markers to compare the genetic variation present within continental Antarctic, sub-Antarctic and temperate populations of the moss Ceratodon purpureus. 3 In contrast to the RAPD studies, microsatellite data revealed that C. purpureus populations from continental Antarctica display less intra-population genetic diversity than populations from a range of temperate and sub-Antarctic sites. 4 Analysis of Molecular Variation (AMOVA) revealed that populations within the …
Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson
Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson
Faculty of Science - Papers (Archive)
We investigated how surface reflectance properties and pigment concentrations of Antarctic moss varied over species, sites, microtopography, and with water content. We found that species had significantly different surface reflectance properties, particularly in the region of the red edge (approximately 700 nm), but this did not correlate strongly with pigment concentrations. Surface reflectance of moss also varied in the visible region and in the characteristics of the red edge over different sites. Reflectance parameters, such as the Photochemical Reflectance Index (PRI) and Cold Hard Band (CBH) were useful discriminators of site, microtopographic position and water content. The PRI was correlated …
Desiccation Tolerance Of Three Moss Species From Continental Antarctica, Sharon A. Robinson, J. Wasley, M. Popp, C. E. Lovelock
Desiccation Tolerance Of Three Moss Species From Continental Antarctica, Sharon A. Robinson, J. Wasley, M. Popp, C. E. Lovelock
Faculty of Science - Papers (Archive)
Tolerance of desiccation was examined in three species of moss, Grimmia antarctici Card., Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., Meyer et Scherb. collected from two sites of contrasting water availability in the Windmill Islands, continental Antarctica. Physiological tolerance to desiccation was measured using chlorophyll fluorescence in plugs of moss during natural drying in the laboratory. Differences in relative water contents, rates of drying and the response of photosynthesis to desiccation were observed among the three species and between sites. Of the three species studied, G. antarctici showed the lowest capacity to sustain photosynthetic processes during desiccation, B. …