The effects of short-term exposition to Cd, excess Cu ions and jasmonate on oxidative stress appearing in Arabidopsis thaliana

In Arabidopsis thaliana leaves, during the first hours of exposition to excess Cu or Cd, a considerable increase of hydrogen peroxide accumulation and superoxide radicals was observed. Imidazole-an inhibitor NADPH oxidase activity and propyl gallate, inhibitor synthesis of jasmonate, mostly decreased this effect. Increased superoxide radicals and hydrogen peroxide level was obtained after exogenous methyl jasmonate supply. Imidazole diminished the effect of methyl jasmonate on hydrogen peroxide burst. Excess Cd, in contrast to Cu, increased in the first hour of SOD activity, but this effect was suppressed by propyl gallate. The results indicated that the first effect of the investigated heavy metals stress was accumulation of superoxide radicals and hydrogen peroxide. That increase was mostly connected with the activity of NADPH oxidase, induction of jasmonate signaling pathways and partially, in the case of Cd, with superoxide dismutase activity increase. (c) 2005 Elsevier B.V. All rights reserved.