Characterisation of a cDNA Encoding γ-Glutamylcysteine Synthetase in Medicago truncatula

• Published in: Free radical research 1999-01, Vol.31 (sup1), p.213-218
• Main Authors: Frendo, Pierre, Mathieu, Christel, Van De Sype, Ghislaine, Hérouart, Didier, Puppo, Alain
• Format: Article
• Language: English
• Subjects: Arabidopsis - enzymology; Arabidopsis - genetics; Base Sequence; Cdna; DNA Primers - genetics; DNA Probes; DNA, Complementary - genetics; DNA, Complementary - isolation & purification; DNA, Plant - genetics; DNA, Plant - isolation & purification; Escherichia coli - genetics; Gene Expression Regulation, Developmental; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Genes, Plant; Glutamate-Cysteine Ligase - genetics; Glutathione; Medicago sativa - enzymology; Medicago sativa - genetics; Medicago sativa - growth & development; Medicago truncatula; Pisum sativum - enzymology; Pisum sativum - genetics; Plant; γ-glutamylcysteine synthetase
• ISSN: 1071-5762; 1029-2470
• DOI: 10.1080/10715769900301531

A gamma-ECS cDNA from Medicago truncatula was isolated using an Arabidopsis thaliana cDNA as probe. The analysis of the amino acid sequence deduced from this cDNA revealed 80% identity with the gamma-ECS from A. thaliana and Brassica juncea and suggested a plastidial localisation for the enzyme. Gamma-ECS activity and high level of GSH were detected in the gamma-ECS-deficient E. coli strain expressing a fusion protein containing the M. truncatula gamma-ECS protein. Southern blot analysis suggests that gamma-ECS is encoded by a small multigenic family in M. truncatula and shows that homologous genes are present in two other leguminous plants, Medicago sativa and Pisum sativum. Gamma-ECS gene expression was analysed by Northern blot in seedlings, plantlets and mature plants.