Acute Exposure to UV-B Sensitizes Cucumber, Tomato, and Arabidopsis Plants to Photooxidative Stress by Inhibiting Thermal Energy Dissipation and Antioxidant Defense

作者：Moon Yu Ran; Lee Min Hee; Tovuu Altanzaya; Lee Choon Hwan; Chung Byung Yeoup; Park Youn Il; Kim Jin Hong^*

来源：Journal of Radiation Research, 2011, 52(2): 238-248.

DOI：10.1269/jrr.10133

Non-photochemical quenching/Reactive oxygen species/Ultraviolet-B/Xanthophyll cycle. To characterize a change in NPQ upon exposure to ultraviolet-B (UV-B), the xanthophyll cycle-dependent and -independent NPQs were compared in Cucumis swims, Lycopersicum esculentum, and Arabidopsis thaliana leaves. The xanthophyll cycle-dependent NPQ was dramatically but reversibly suppressed by UV-B radiation. This suppression was correlated more strongly with a marked decrease in photosynthetic electron transport rather than changes in xanthophyll cycle enzymes such as violaxanthin de-epoxidase and zeaxanthin epoxidase. Accordingly, the UV-B-induced suppression of NPQ cannot be attributed to changes in expressions of VDE and ZEP. However, suppression of the xanthophyll cycle-dependent NPQ could only account for the 77 K fluorescence emission spectra of thylakoid membranes and the increased level of (1)O(2) production, but not for the decreased levels of center dot O(2)(-) production and H(2)O(2) scavenging. These results suggest that a gradual reduction of H(2)O(2) scavenging activity as well as a transient and reversible suppression of thermal energy dissipation may contribute differentially to increased photooxidative damages in cucumber, tomato, and Arabidopsis plants after acute exposure to UV-B radiation.

• 出版日期2011-3