| Autor: |
Bolink, EM, van Schalkwijk, [No Value], Posthumus, F, van Hasselt, PR |
| Jazyk: |
angličtina |
| Rok vydání: |
2001 |
| Předmět: |
|
| Zdroj: |
Plant ecology, 154(1-2), 147 |
| ISSN: |
1385-0237 |
| Popis: |
Pea (Pisum sativum L.) and bean (Phaseolus vulgaris L.) plants were exposed to enhanced levels of UV-B radiation in a growth chamber. Leaf discs of UV-B treated and control plants were exposed to high-light (HL) stress (PAR: 1200 mu mol m(-2) s(-1)) to study whether pre-treatment with UV-B affected the photoprotective mechanisms of the plants against photoinhibition. At regular time intervals leaf discs were taken to perform chlorophyll a fluorescence and oxygen evolution measurements to assess damage to the photosystems. Also, after 1 h of HL treatment the concentration of xanthophyll cycle pigments was determined. A significantly slower decline of maximum quantum efficiency of PSII (F(v)/F(m)), together with a slower decline of oxygen evolution during HL stress was observed in leaf discs of UV-B treated plants compared to controls in both plant species. This indicated an increased tolerance to HL stress in UV-B treated plants. The total pool of xanthophyll cycle pigments was increased in UV-B treated pea plants compared to controls, but in bean no significant differences were found between treatments. However, in bean plants thiol concentrations were significantly enhanced by UV-B treatment, and UV-absorbing compounds increased in both species, indicating a higher antioxidant capacity. An increased leaf thickness, together with increases in antioxidant capacity could have contributed to the higher protection against photoinhibition in UV-B treated plants. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink