Opposing roles for superoxide and nitric oxide in the NaCl stress-induced upregulation of antioxidant enzyme activity in cotton callus tissue

Proline and Glycinebetaine Ameliorated NaCl Stress via Scavenging of Hydrogen Peroxide and Methylglyoxal but Not Superoxide or Nitric Oxide in Tobacco Cultured Cells

“…Salt stress-induced accumulation of H 2 O 2 and O 2 À and a reduction in cell viability have been reported in plants. 14,16) In BY-2 cells, both the short-term (3 h) and the long-term (4 d) NaCl treatment induced H 2 O 2 accumulation (Fig. 1A and B), while only the long-term NaCl treatment increased O 2 À levels (Fig.…”

“…3A and B). 16) On the other hand, NaCl has been found to decrease the NO level by inhibiting NO synthase activity in Arabidopsis mutant (Atnoa1) plants with impaired in vivo NO synthase activity, and in wild-type plants as well, 15) but simultaneous increases in NO and H 2 O 2 in tobacco cells induce apoptosis-like cell death. 20) In BY-2 cells, proline and betaine did not reduce NO production under either short-term or long-term NaCl treatment ( Fig.…”

“…8) Environmental stress, including salinity, induces the production of hydrogen peroxide (H 2 O 2 ), the superoxide radical (O 2 À ), and nitric oxide (NO) in plant cells. 1,[12][13][14][15][16][17][18] Excess production of H 2 O 2 , O 2 À , and NO is toxic to plants, and causes oxidative damage to cellular constituents, leading to cell death. [12][13][14][18][19][20] In plant cells, salinity also leads to the accumulation of methylglyoxal (MG), a cytotoxic compound that can react with and modify other molecules, including DNA and proteins.…”

Signal mediators at induction of heat resistance of wheat plantlets by short-term heating

“…It is difficult to explain this effect without special investigations. Probably, the NO decrease in cells in itself serves as a stressfactor activating the plant protective systems [19]. Earlier the increase of activity of antioxidative enzymes superoxide dismutase, catalase and guaiacol peroxidase has been shown by us under the influence of NO scavenger PTIO and NO-synthase inhibitor L-NAME on wheat plantlets [20].…”

“…3, B). There are data in the literature, that the nitric oxi de can influence the enzymatic systems generating ROS, in particular, NADPH oxidase [30], and also antioxidative enzymes [19] and thus regulate the content of ROS. The influence of ROS on the activi ty of NO-generating enzymes is less investigated.…”