Cell wall-bound ultraviolet-screening compounds explain the high ultraviolet tolerance of the Antarctic moss, Ceratodon purpureus
Article first published online: 30 MAY 2008
© The Authors (2008). Journal compilation © New Phytologist (2008)
Volume 179, Issue 3, pages 776–783, August 2008
How to Cite
Clarke, L. J. and Robinson, S. A. (2008), Cell wall-bound ultraviolet-screening compounds explain the high ultraviolet tolerance of the Antarctic moss, Ceratodon purpureus. New Phytologist, 179: 776–783. doi: 10.1111/j.1469-8137.2008.02499.x
- Issue published online: 15 JUL 2008
- Article first published online: 30 MAY 2008
- Received: 19 February 2008Accepted: 3 April 2008
- Bryum pseudotriquetrum;
- cell wall;
- Ceratodon purpureus;
- confocal microscopy;
- ozone depletion;
- Schistidium antarctici (Grimmia antarctici);
- UV-screening compounds
- • 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. purpureus the concentration of cell wall-bound screening compounds was six times higher than the concentration of MeOH-soluble UV screens. The Antarctic endemic Schistidium antarctici possessed half the combined pool of UV screens of the other species but, as in C. purpureus, these were predominantly cell wall bound. Confocal microscopy confirmed the localization of UV screens in each species.
- • Greater investment in cell wall-bound UV screens offers C. purpureus a more spatially uniform, and potentially more effective, UV screen. Schistidium antarctici has the lowest UV-screening potential, indicating that this species may be disadvantaged under continuing springtime ozone depletion. Cell wall compounds have not previously been quantified in bryophytes but may be an important component of the UV defences of lower plants.