Localization of γ-Glutamylcysteine Synthetase and Glutathione Synthetase Activity in Maize Seedlings

Rüegsegger, Adrian; Brunold, Christian (1993). Localization of γ-Glutamylcysteine Synthetase and Glutathione Synthetase Activity in Maize Seedlings. Plant Physiology, 101(2), pp. 561-566. American Society of Plant Physiologists 10.1104/pp.101.2.561

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Fresh weight, protein, cysteine, γ-glutamylcysteine, glutathione, and the extractable activity of the enzymes of glutathione biosynthesis, γ-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots, scutella, endosperms, and shoots of 3-, 7-, and 11-d-old maize (Zea mays L. cv LG 9) seedlings. In 3-d-old seedlings, the scutella represented 14% of the seedling fresh weight, containing 43% of total protein and 63 and 55% of the activity of [gamma]-glutamylcysteine synthetase and glutathione synthetase, respectively; in 11-d-old seedlings, the corresponding values were 4.5% for fresh weight, 8.0% for protein content, and 14 and 20% for the enzyme activities. The highest concentrations of thiols were found for cysteine (0.27 mM) in the roots, for glutathione (4.4 mM) in the shoots, and for γ-glutamylcysteine (13 [mu]M) in the scutella of 3-d-old seedlings. The enzyme activities of roots were localized in subcellular fractions after sucrose density gradient centrifugation. Nearly half of the γ-glutamylcysteine synthetase activity was detected in the root proplastids of 4-d-old seedlings, whereas <10% of the glutathione synthetase activity was localized in this organelle. Our results demonstrate the importance of scutella in glutathione synthesis in the early stage of seedling development. Unlike chloroplasts, root plastids show only a small proportion of glutathione synthetase activity.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Stress Physiology (discontinued)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Brunold, Christian

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0032-0889

Publisher:

American Society of Plant Physiologists

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

25 Jul 2018 13:31

Last Modified:

21 Nov 2019 00:37

Publisher DOI:

10.1104/pp.101.2.561

BORIS DOI:

10.7892/boris.118953

URI:

https://boris.unibe.ch/id/eprint/118953

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