Cetaceans and fishery interactions along the Espírito Santo State, Southeastern Brazil during 1994-2001

Abstract

To gain better insights into the generation of oxidative stress by NaClstress, we compared the effects of toxic, sublethal concentrations ofNaCl (150 mM) with those of CuSO4 (100 mu M) On the antioxidant defenceresponses of Nicotiana plumbaginifolia L. plants grown in hydroponicculture. Short- and long-term adaptive responses were investigated aswell as the effects of root cutting to allow rapid absorption of ions.Our results show that photosynthesis is already affected after 12 h ofboth treatments and that photoinhibition is induced. Furthermore, thetwo treatments showed distinct patterns of induction of the genes of theantioxidant systems. Principally, NaCl stimulated catalase activitythrough activation of the Cat2 and Call genes, whereas with CuSO4,transcript levels, protein levels, and enzymatic activities ofglutathione peroxidase, ascorbate peroxidase, and superoxide dismutasewere differentially induced. The antioxidants ascorbate and glutathionewere found to be largely oxidized after 12 h, suggesting an inability ofthe recycling process to cope with the stress, In addition, both NaCland CuSO4 treatments stimulated the accumulation of the osmolyteproline, Therefore, we conclude that the uptake and accumulation ofdifferent types of ions lead to the generation of distinct antioxidantresponses in N. plumbaginifolia.