Properties and functions of glutathione reductase in plants

The assay and in vitro characterization of glutathione reductase (EC 1.6.4.2) is discussed. In vivo the H 2 O 2 ‐scavenging system in chloroplasts is the best documented role of reduced glutathione and glutathione reductase in plants. Similarly, redaction of H 2 O 2 , outside of the chloroplasts, requires glutathione and glutathione reductase; but the pathway, in terms of intermediates, is controversial. The notion that biological stress frequently causes cellular oxidation has lead to the suggestion that glutathione and glutathione reductase may play a role in stress resistance or tolerance mechanisms. The changes in glutathione reductase levels in response to low temperature, oxidative stress and drought are discussed.