Detection of S-Nitrosoglutathione Reductase Activity in Plants.

S-nitrosoglutathione reductase (GSNOR) is considered a key enzyme in the regulation of intracellular levels of S-nitrosoglutathione and protein S-nitrosylation. As a part of nitric oxide catabolism, GSNOR catalyzes the irreversible decomposition of GSNO to oxidized glutathione. GSNOR is involved in the regulation of plant growth and development, mediated by NO-dependent signaling mechanisms, and is known to play important roles in plant responses to various abiotic and biotic stress conditions. Here we present optimized protocols to determine GSNOR enzyme activities in plant samples by spectrophotometric measurements and by activity staining after the native polyacrylamide gel electrophoresis.