Abiotic stress alters transcript profiles and activity of glutathione S‐transferase, glutathione peroxidase, and glutathione reductase in Euphorbia esula

Abstract

Glutathione S-transferase (GST), glutathione peroxidase (GPX), and glutathione reductase (GR) are enzymes that utilize glutathione to play an important role in plant defense mechanisms. In leafy spurge (Euphorbia esula L.), transcript and activity profiles for these enzymes are differentially influenced in tissue exposed to xenobiotic (diclofop-methyl) and environmental stress (cold and drought). Five different EeGST cDNA (including phi, tau, theta, and zeta class GSTs), one EeGPX cDNA, and one EeGR cDNA showed differential expression patterns in leafy spurge plants exposed to diclofop-methyl-, cold- and drought-stress. Tissue treated with diclofop-methyl also had increased GST, GPX and GR activities that were preceded or paralleled by increased gene expression. Transcript profiles resulting from drought-stressed plants were similar to transcript profiles from diclofop-methyl-treated plants but not cold-stressed plants. GPX activity in leafy spurge protein extracts was not bound to either S-hexylglutathione- or glutathione-agarose columns but instead co-migrated with fractions of GST activity that also were not bound by affinity chromatography. Fractions of GST proteins that were bound to S-hexylglutathione revealed that increased GST activity in diclofop-methyl-treated tissue could be identified as phi- and tau-type GSTs.

Plant Defense Responses in Opium Poppy Cell Cultures Revealed by Liquid Chromatography-Tandem Mass Spectrometry Proteomics

“…5), others represented in the opium poppy EST databases were not induced at the transcriptional level suggesting a defensive role for specific members. GSTs typically display differential regulation in response to various biotic and abiotic stresses (36,37).…”

Effects of Feeding Spodoptera littoralis on Lima Bean Leaves. III. Membrane Depolarization and Involvement of Hydrogen Peroxide

“…GPX (EC 1.11.1.9) GPX was assayed indirectly, as described by Anderson and Davis (2004). The reaction contained 125 mM K-P buffer, pH 7.0, 1.2 mM cumene hydroperoxide, 1.25 mM EDTA, 1.25 mM sodium azide, 1.0 mM glutathione, 0.25 mM NADPH, 0.6 IU of yeast GR (Sigma Type III), and enzyme extract in a final volume of 1 mL.…”

Glutathione S-Transferase activities and glutathione levels in needles of drought stressed Pinus brutia Ten. trees

“…Meteorological data put the presence of possible environmental stress conditions forth as an inducer of the total GST activity. During all season, those climatic conditions continued to end with higher GST activities, as expected [21][22][23][24][25]. From the beginning of the summer season till the middle, together with an increase in temperature, there was a decrease in precipitation, possibly causing lowered soil humidity.…”