Early signaling components in ultraviolet-B responses: distinct roles for different reactive oxygen species and nitric oxide

FEBS Lett. 2001 Feb 2;489(2-3):237-42. doi: 10.1016/s0014-5793(01)02103-2.


The nature and origin of the reactive oxygen species (ROS) involved in the early part of Ultraviolet-B (UV-B)-induced signaling pathways were investigated in Arabidopsis thaliana using a range of enzyme inhibitors and free radical scavengers. The increase in PR-1 transcript and decrease in Lhcb transcript in response to UV-B exposure was shown to be mediated through pathways involving hydrogen peroxide (H(2)O(2)) derived from superoxide (O(2)(&z.rad;-)). In contrast, the up-regulation of PDF1.2 transcript was mediated through a pathway involving O(2)(&z.rad;-) directly. The origins of the ROS were also shown to be distinct and to involve NADPH oxidase and peroxidase(s). The up-regulation of Chs by UV-B was not affected by ROS scavengers, but was reduced by inhibitors of nitric oxide synthase (NOS) or NO scavengers. Together these results suggest that UV-B exposure leads to the generation of ROS, from multiple sources, and NO, through increased NOS activity, giving rise to parallel signaling pathways mediating responses of specific genes to UV-B radiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / genetics
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis / radiation effects*
  • Catalase / pharmacology
  • Dose-Response Relationship, Drug
  • Free Radical Scavengers / pharmacology
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Glutathione / analogs & derivatives*
  • Glutathione / pharmacology
  • Hydrogen Peroxide / metabolism
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / metabolism
  • Nitric Oxide / physiology
  • Nitroso Compounds / pharmacology
  • Photosynthetic Reaction Center Complex Proteins / genetics
  • Plant Proteins / genetics
  • RNA, Ribosomal, 18S / genetics
  • Reactive Oxygen Species / metabolism
  • Reactive Oxygen Species / physiology
  • S-Nitrosoglutathione
  • Salicylamides / pharmacology
  • Signal Transduction / drug effects
  • Signal Transduction / radiation effects*
  • Superoxide Dismutase / pharmacology
  • Superoxides / metabolism
  • Ultraviolet Rays*


  • Free Radical Scavengers
  • Nitroso Compounds
  • Photosynthetic Reaction Center Complex Proteins
  • Plant Proteins
  • RNA, Ribosomal, 18S
  • Reactive Oxygen Species
  • Salicylamides
  • pathogenesis-related proteins, plant
  • Superoxides
  • Nitric Oxide
  • S-Nitrosoglutathione
  • salicylhydroxamic acid
  • Hydrogen Peroxide
  • Catalase
  • Superoxide Dismutase
  • Acyltransferases
  • flavanone synthetase
  • Glutathione
  • NG-Nitroarginine Methyl Ester