ISSN:
1365-3040
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
There have been many reports suggesting the involvement of reactive oxygen species (ROS), including superoxide anion (O2.–), in salt stress. Herein, direct evidence that treatments of cell suspension culture of tobacco (Nicotiana tabacum L.; cell line, BY-2) with various salts of trivalent, divalent and monovalent metals stimulate the immediate production of O2.– is reported. Among the salts tested, LaCl3 and GdCl3 induced the greatest responses in O2.– production, whereas CaCl2 and MgCl2 showed only moderate effects; salts of monovalent metals such as KCl and NaCl induced much lower responses, indicating that there is a strong relationship between the valence of metals and the level of O2.– production. As the valence of the added metals increased from monovalent to divalent and trivalent, the concentrations required for maximal responses were lowered. Although O2.– production by NaCl and KCl required high concentrations associated with hyperosmolarity, the O2.– generation induced by NaCl and KCl was significantly greater than that induced simply by hyperosmolarity. Since an NADPH oxidase inhibitor, diphenyleneiodonium chloride, showed a strong inhibitory effect on the trivalent and divalent cation-induced generation of O2.–, it is likely that cation treatments activate the O2.–-generating activity of NADPH oxidase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-3040.2001.00766.x
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