Localization of S-nitrosothiols and assay of nitric oxide synthase and S-nitrosoglutathione reductase activity in plants.

The study of the metabolism of nitric oxide and other reactive nitrogen species (RNS) in plants has been the subject of intensive work in the last decade due to the relevance of these molecules in the physiology and biochemistry of plants. However, there are still many methodological limitations in the specific and accurate determination and localization of RNS. This chapter describes several biochemical and cellular methods demonstrated to be useful for this purpose in different plant tissues. These methods are the determination of L-arginine-dependent nitric oxide synthase and S-nitrosoglutathione reductase activities, as well as cellular localization by confocal laser-scanning microscopy of S-nitrosothiols, particularly S-nitrosoglutathione. These approaches can help advance the knowledge of the function of RNS in plant cells.