Protective pigmentation in UVB-screened Antarctic lichens studied by Fourier transform Raman spectroscopy: an extremophile bioresponse to radiation stress

• Published in: Journal of Raman spectroscopy 2004-06, Vol.35 (6), p.463-469
• Main Authors: Edwards, Howell G. M., Cockell, Charles S., Newton, Emma M., Wynn-Williams, David D.
• Format: Article
• Language: English
• Subjects: Antarctic lichens; Antarctica; Bands; Caloplaca; Fourier transforms; Habitats; Lichens; Mars analogues; photoprotective pigments; Pigments; radiation stress; Raman spectroscopy; Spectra; UV radiation stress; Xanthoria elegans
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.1172

FT‐Raman spectra were obtained for two Antarctic extremophiles, the epilithic lichens Xanthoria elegans and Caloplaca sublobulata from the maritime ecological long‐term research site on Leonie Island. Twelve specimens from cloches designed for the filtering out and transmission of UVB radiation over a 2 year period and two specimens from the natural habitat outside the cloches were analysed in terms of their characteristic Raman bands from the two photoprotective pigments parietin and β‐carotene. Following chemometric analysis, the specimens inside the UVB‐protective cloches exhibited a lower parietin:β‐carotene ratio than specimens from the same habitat that did not have UVB protection. The relative roles of parietin, a passive UVB photoprotectant, and β‐carotene are discussed and a possible duality of biological function is suggested for these pigments. Copyright © 2004 John Wiley & Sons, Ltd.