Sequential reduction of UV-B radiation in the field alters the pigmentation of an Antarctic leafy liverwort

UV-B radiation (280–315 nm), incident on the leafy liverwort Cephaloziella varians growing at Rothera Point on the Western Antarctic Peninsula, was manipulated in late austral spring 1998 by screens consisting of a novel combination of Plexiglas panes and polyester sheets. The screens transmitted approximately 79, 68, 48, 41 and 31% of daily UV-B radiation dose. Plants from under and outside the screens were sampled seven times over 35 days. Correlative analyses indicated that concentrations of an anthocyanin-like pigment located in leaf tips were positively associated with UV-B transmission at the last two samplings, that concentrations of total chlorophylls were negatively associated with UV-B transmission at the final sampling, and that those of UV-B screening pigments were positively correlated with transmission at three intermediate samplings. Plants exposed to low UV-B transmission levels were visibly greener than those exposed to high transmission levels after approximately 23 days. The closest relationships between the treatment and concentrations of UV-B screening pigments were associated with increased ambient biologically weighted UV-B dose received by plants in the 5.5 h before each sampling, which coincided with the passage of the ozone hole over Rothera Point. As C. varians emerged from melting snow and ice, concentrations of the anthocyanin-like pigment and chlorophyll respectively increased and decreased faster in plants exposed to high transmission levels of UV-B, relative to those exposed to low UV-B transmission levels.

Details

Publication status:
Published
Author(s):
Authors: Newsham, K.K., Geissler, P.A., Nicolson, M.J., Peat, H.J., Lewis-Smith, R.I.

On this site: Helen Peat, Kevin Newsham, Paul Geissler
Date:
1 January, 2005
Journal/Source:
Environmental and Experimental Botany / 54
Page(s):
22-32
Digital Object Identifier (DOI):
https://doi.org/10.1016/j.envexpbot.2004.05.006