Prospects for enhancement of the soluble antioxidants, ascorbate and glutathione

Article type: Research Article

Authors: Foyer, Christine H.

Affiliations: Crop Performance and Improvement Division, IACR-Rothamsted, Harpenden, Hertfordshire AL5 2JQ, UK. Tel.: +44 01582 763133, x2636; Fax: +44 01582 763010; E-mail: [email protected]

Abstract: Ascorbic acid (vitamin C) and the tripeptide thiol, glutathione γ-glutamyl cysteinyl glycine (glutathione) are the major low molecular weight soluble antioxidants in plant cells. The pathway of glutathione biosynthesis is similar in animals and plants while that of ascorbate biosynthesis differs considerably between the two kingdoms. The potential for obtaining substantial constitutive changes in the tissue contents of these antioxidants by manipulation of the biosynthetic enzymes has been demonstrated. Moreover, the concentrations of ascorbate and glutathione are greatly modified in response to a variety of environmental triggers, particularly those that cause increased oxidative stress. It is essential that the signals and associated signal transduction pathways that trigger enhanced antioxidant accumulation are elucidated as these offer an important alternative means of achieving greater nutritional value in edible plant organs.

Journal: BioFactors, vol. 15, no. 2-4, pp. 75-78, 2001