Regulation of glutathione synthesis in leaves of transgenic poplar (Populus tremula X P. alba) overexpressing glutathione synthetase

• Published in: The Plant journal : for cell and molecular biology Vol. 7; no. 1; pp. 141 - 145
• Main Authors: Strohm, M, Jouanin, L, Kunert, K.J, Pruvost, C, Polle, A, Foyer, C.H, Rennenberg, H
• Format: Journal Article
• Language: English
• Published: Osney Mead, Oxford OX2 0EL, UK Blackwell Science Ltd 1995; Blackwell Science; Wiley
• Subjects: Agronomy. Soil science and plant productions; biochemical pathways; Biological and medical sciences; biosynthesis; cysteine; cytosol; Economic plant physiology; enzyme activity; Escherichia coli; Fundamental and applied biological sciences. Psychology; gamma-glutamylcysteine; gene expression; genetic regulation; Genetics; glutathione; glutathione synthase; hybrids; leaves; Life Sciences; Metabolism; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Plants genetics; Populus alba; Populus tremula; precursors; strain differences; transgenic plants; Carbon-nitrogen ligases; Enzyme; Gene overexpression; Biosynthesis; Salicaceae; Glutathione synthase; Regulation(control); Enzymatic activity; Ligases; Dicotyledones; Angiospermae; Hardwood forest tree; Transgenic plant; Spermatophyta; Cytoplasm; Glutathione; PEUPLIER
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.1995.07010141.x

The poplar hybrid Populus tremula X P. alba was transformed with the Escherichia coli gene for glutathione synthetase (gsh II) targetted to the cytosol. Leaves of five lines of transgenic plants exhibited glutathione synthetase activities 15‐ to 60‐fold higher than those of wild‐type plants. Total glutathione levels and GSH/GSSG ratios were similar in transgenic and wild‐type plants. Precursor feeding experiments with cysteine and γ‐glutamylcysteine suggest that glutathione synthesis in the cytoplasm is controlled by a multistep procedure that includes (i) the availability of cysteine, (ii) the availability of γ‐glutamylcysteine, and (iii) regulation of the activities of both γ‐glutamylcysteine synthetase and glutathione synthetase. However step (ii) may set an upper limit for the cellular glutathione content.