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Localisation of glutathione and homoglutathione in Medicago truncatula is correlated to a differential expression of genes involved in their synthesis
Author(s) -
Frendo Pierre,
Gallesi Daniela,
Turnbull Ruth,
Van de Sype Ghislaine,
Hérouart Didier,
Puppo Alain
Publication year - 1999
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1999.00367.x
Subject(s) - medicago truncatula , glutathione , biology , medicago , glutathione synthetase , gene , gene expression , western blot , microbiology and biotechnology , botany , biochemistry , genetics , enzyme , symbiosis , bacteria
Summary Glutathione (GSH) and homoglutathione (hGSH) were quantified inMedicago truncatuladuring plant development. hGSH was detectable only 48 h after seed germination whereas GSH was present in the dry seeds, indicating that only GSH is used for sulphur storage in seeds. The hGSH was detectable only in the underground part of mature plants whereas GSH was present in all the organs. γ‐EC synthetase (γ‐ECS) and GSH synthetase (GSHS) activities were found in roots and leaves whereas hGSH synthetase (hGSHS) was found only in roots. Full‐length cDNA encoding γ‐ECS and two partial cDNAs (gshs1andgshs2) showing high identity with GSHS were isolated inM. truncatula. High γ‐ECS activity was detected in protein extracts of a γ‐ECS‐deficientE. colistrain expressing theM. truncatulaγ‐ECS. Northern blot analysis showed that the γ‐ECS gene was similarly expressed in all the mature plant organs tested, whereasgshs1had a higher expression in leaves and flowers andgshs2was preferentially expressed in roots and nodules. We hypothesise thatgshs1andgshs2encode a GSHS and an hGSHS, respectively.