Jasmonic acid regulates ascorbate and glutathione metabolism in Agropyron cristatum leaves under water stress

This study investigated the regulation of ascorbate and glutathione metabolism by jasmonic acid (JA) in Agropyron cristatum leaves underwater stress induced by 10% PEG 6000. The results showed that JA level, the transcript levels and activities of APX, GR, MDHAR, DHAR, GaILDH and gamma-ECS, and the contents of AsA, total ascorbate and total glutathione were increased by water stress. Above increases except for total glutathione content and the transcript level and activity of gamma-ECS were suppressed by application of JA biosynthesis inhibitor ibuprofen (IBU), a lipoxygenase inhibitor, for 12 h before water stress treatment. Application of JA to IBU-inhibited plants prevented the reduction in the transcript levels and activities of GaILDH, APX, GR, DHAR and MDHAR, and the contents of AsA, GSH, total ascorbate induced by IBU under water stress. Meanwhile, pretreatment with IBU increased the malondialdehyde content and electrolyte leakage of plants and these increases were suppressed by application of JA under water stress. Our results suggested that water stress-induced]A is a signal that leads to the regulation of ascorbate and glutathione metabolism and has important role for acquisition of water stress tolerance in A. cristatum. (C) 2009 Elsevier Ireland Ltd. All rights reserved.