Watson, Jonathon S.; Sephton, Mark A.; Sephton, Sarah V.; Self, Stephen; Fraser, Wesley T.; Lomax, Barry H.; Gilmour, Iain; Wellman, Charles H. and Beerling, David J.
(2007).
| DOI (Digital Object Identifier) Link: | http://dx.doi.org/doi:10.1039/b617794h |
|---|---|
| Google Scholar: | Look up in Google Scholar |
Abstract
Spore chemistry is at the centre of investigations aimed at producing a proxy record of harmful ultraviolet radiation (UV-B) through time. A biochemical proxy is essential owing to an absence of long-term (century or more) instrumental records. Spore cell material contains UV-B absorbing compounds that appear to be synthesised in variable amounts dependent on the ambient UV-B flux. To facilitate these investigations we have developed a rapid method for detecting variations in spore chemistry using combined thermochemolysis gas chromatography-mass spectrometry and micro-Fourier transform infrared spectroscopy. Our method was tested using spores obtained from five populations of the tropical lycopsid Lycopodium cernuum growing across an altitudinal gradient (650–1981 m a.s.l.) in S.E. Asia with the assumption that they experienced a range of UV-B radiation doses. Thermochemolysis and subsequent pyrolysis liberated UV-B pigments (ferulic and para-coumaric acid) from the spores. All of the aromatic compounds liberated from spores by thermochemolysis and pyrolysis were active in UV-B protection. The various functional groups associated with UV-B protecting pigments were rapidly detected by micro-FTIR and included the aromatic CC absorption band which was exclusive to the pigments. We show increases in micro-FTIR aromatic absorption (1510 cm–1) with altitude that may reflect a chemical response to higher UV-B flux. Our results indicate that rapid chemical analyses of historical spore samples could provide a record ideally suited to investigations of a proxy for stratospheric O3 layer variability and UV-B flux over historical (century to millennia) timescales.
| Item Type: | Journal Article |
|---|---|
| ISSN: | 1474-905X |
| Academic Unit/Department: | Science > Physical Sciences Science > Environment, Earth and Ecosystems |
| Interdisciplinary Research Centre: | Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR) |
| Item ID: | 7463 |
| Depositing User: | Astrid Peterkin |
| Date Deposited: | 30 May 2007 |
| Last Modified: | 02 Dec 2010 19:59 |
| URI: | http://oro.open.ac.uk/id/eprint/7463 |
Actions (login may be required)
| View Item | |
| Public: Report issue / request change |