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Antioxidant defence in UV-irradiated tobacco leaves is centred on hydrogen-peroxide neutralization
Majer, Petra; Czegeny, Gyula; Sandor, Gyorgyi; Dix, Philip; Hideg, Eva
Greenhouse grown tobacco (Nicotiana tabacum L. cv. Petit Havana) plants were exposed to supplemental UV centred at 318 nm and corresponding to 13.6 kJ m-2 d-1 biologically effective UV-B (280e315 nm) radiation. After 6 days this treatment decreased photosynthesis by 30%. Leaves responded by a large increase in UV-absorbing pigment content and antioxidant capacities. UV-stimulated defence against ROS was strongest in chloroplasts, since activities of plastid enzymes FeSOD and APX had larger relative increases than other, non-plastid specific SODs or peroxidases. In addition, non-enzymatic defence against hydroxyl radicals was doubled in UV treated leaves as compared to controls. In UV treated leaves, the extent of activation of ROS neutralizing capacities followed a peroxidases > hydroxyl-radical neutralization > SOD order. These results suggest that highly effective hydrogen peroxide neutralization is the focal point of surviving UV-inducible oxidative stress and argue against a direct signalling role of hydrogen peroxide in maintaining adaptation to UV, at least in laboratory experiments.
Keyword(s): Antioxidant; Peroxidase; Photosynthesis; Reactive oxygen species; Hydrogen peroxide; Tobacco; UV treatment
Publication Date:
Type: Journal article
Peer-Reviewed: Yes
Institution: Maynooth University
Citation(s): Majer, Petra and Czegeny, Gyula and Sandor, Gyorgyi and Dix, Philip and Hideg, Eva (2014) Antioxidant defence in UV-irradiated tobacco leaves is centred on hydrogen-peroxide neutralization. Plant Physiology and Biochemistry, 82. pp. 239-243. ISSN 0981-9428
Publisher(s): Elsevier
File Format(s): other
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First Indexed: 2016-01-20 05:00:35 Last Updated: 2018-09-04 06:13:13