| Autor: |
David W. Fountain, Kenneth R. Markham, Rainer W. Hofmann, B. D. Campbell, Ken G. Ryan, Stephen J. Bloor, Ewald E. Swinny |
| Rok vydání: |
2003 |
| Předmět: |
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| Zdroj: |
Plant, Cell & Environment. 26:603-612 |
| ISSN: |
0140-7791 |
| Popis: |
This study used comparisons across nine populations of Trifolium repens (white clover) in conjunction with drought to examine physiological responses to ultravioletB radiation (UV-B). Plants were exposed for 12 weeks to supplementation with 13.3 kJ m - 2 d - 1 UV-B, accompanied by 4 weeks of drought under controlled environmental conditions. UV-B increased the levels of UV-B-absorbing compounds and of flavonol glycosides and this effect was synergistically enhanced by water stress. These changes were more pronounced for the ortho -dihydroxylated quercetin, rather than the monohydroxylated kaempferol glycosides. UV-B increased leaf water potential ( y L ) by 16% under drought and proline levels by 23% under wellwatered conditions. The intraspecific comparisons showed that higher UV-B-induced levels of UV-B-absorbing compounds, of quercetin glycosides and of y L were linked to lower plant productivity and to higher UV-B tolerance under well-watered conditions. These findings suggest that: (1) slow-growing T. repens ecotypes adapted to other stresses have higher capacity for physiological acclimation to UV-B; and (2) that these attributes also contribute to decreased UV-B sensitivity under drought. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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