Abstract
To study the relationship between drought and oxidative stress and mechanisms of photo- and antioxidative protection in strawberry tree (Arbutus unedo L.), the endogenous concentrations of xanthophyll cycle pigments, α-tocopherol and reduced and oxidized ascorbate were measured in 2-year-old plants exposed to a combination of water deficit, high light and high temperatures in Mediterranean field conditions. Under moderate stress (relative leaf water content [RWC] of ca. 68%), levels of photosynthetic pigments (chlorophylls and carotenoids) and ascorbate were kept constant, while α-tocopherol levels increased by ca. 50%. Under severe stress (RWC of ca. 53%): (i) α-tocopherol levels remained high, (ii) zeaxanthin concentrations increased by 75%, (iii) ascorbate increased by 54% and its redox state shifted towards its oxidized form, and (iv) chlorophylls, lutein and β-carotene decreased by ca. 63, 61 and 75%, respectively. These results are consistent with the contentions that drought causes oxidative stress in A. unedo plants, and that mechanisms of photo- and antioxidative protection contribute to withstand drought-induced oxidative stress in this Mediterranean plant species. © 2004 Elsevier Ireland Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 1105-1110 |
Journal | Plant Science |
Volume | 166 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Apr 2004 |
Keywords
- α-Tocopherol
- Activated oxygen species
- Antioxidants
- AOS
- Ascorbate
- Carotenoids
- Chl
- Chlorophyll a+b
- De-epoxidation state of the xanthophyll cycle
- DPS
- Drought
- Dry weight
- DW
- H
- Hydration of leaves
- Oxidative stress
- Strawberry tree (Arbutus unedo L.)