Functional acclimation to solar UV-B radiation in Gunnera magellanica, a native plant species of southernmost Patagonia
The ecosystems of Tierra del Fuego (in southern Patagonia, Argentina) are seasonally exposed to elevated levels of ultraviolet-B radiation (UV-B: 280-315 nm), due to the passage of the 'ozone hole' over this region. In the experiments reported in this article the effects of solar UV-B and UV-A (315-...
| Authors: | ; ; ; ; ; |
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| Format: | Article |
| Status: | Published version |
| Publication date: | 2003 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/152139 |
| Online Access: | http://hdl.handle.net/11336/152139 |
| Access Level: | Open access |
| Keyword: | CYCLOBUTANE-PYRIMIDINE DIMER PHOTOREPAIR OZONE DEPLETION UV-ABSORBING COMPOUNDS UV-B https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 |
| Summary: | The ecosystems of Tierra del Fuego (in southern Patagonia, Argentina) are seasonally exposed to elevated levels of ultraviolet-B radiation (UV-B: 280-315 nm), due to the passage of the 'ozone hole' over this region. In the experiments reported in this article the effects of solar UV-B and UV-A (315-400 nm) on two UV-B defence-related processes: the accumulation of protective UV-absorbing compounds and DNA repair, were tested. It was found that the accumulation of UV-absorbing sunscreens in Gunnera magellanica leaves was not affected by plant exposure to ambient UV radiation. Photorepair was the predominant mechanism of cyclobutane-pyrimidine dimer (CPD) removal in G. magellanica. Plants exposed to solar UV had higher CPD repair capacity under optimal conditions of temperature (25 °C) than plants grown under attenuated UV. There was no measurable repair at 8 °C. The rates of CPD repair in G. magellanica plants were modest in comparison with other species and, under equivalent conditions, were about 50% lower than the repair rates of Arabidopsis thaliana (Ler ecotype). Collectively our results suggest that the susceptibility of G. magellanica plants to current ambient levels of solar UV-B in southern Patagonia may be related to a low DNA repair capacity. |
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