Antioxidant defence in UV-irradiated tobacco leaves is centred on hydrogen-peroxide neutralization

Petra Majer, Gyula Czégény, Györgyi Sándor, Philip J. Dix, Éva Hideg

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12 Citations (Scopus)

Abstract

Greenhouse grown tobacco (Nicotiana tabacum L. cv. Petit Havana) plants were exposed to supplemental UV centred at 318nm and corresponding to 13.6kJm-2d-1 biologically effective UV-B (280-315nm) 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.

Original languageEnglish
Pages (from-to)239-243
Number of pages5
JournalPlant Physiology and Biochemistry
Volume82
DOIs
Publication statusPublished - Sep 2014

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Keywords

  • Antioxidant
  • Hydrogen peroxide
  • Peroxidase
  • Photosynthesis
  • Reactive oxygen species
  • Tobacco
  • UV treatment

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science

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