Cyst(e)ine Is the Transport Metabolite of Assimilated Sulfur from Bundle-Sheath to Mesophyll Cells in Maize Leaves

Burgener, Marta; Suter, Marianne; Jones, Stephanie; Brunold, Christian (1998). Cyst(e)ine Is the Transport Metabolite of Assimilated Sulfur from Bundle-Sheath to Mesophyll Cells in Maize Leaves. Plant Physiology, 116(4), pp. 1315-1322. American Society of Plant Physiologists 10.1104/pp.116.4.1315

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The intercellular distribution of the enzymes and metabolites of assimilatory sulfate reduction and glutathione synthesis was analyzed in maize (Zea mays L. cv LG 9) leaves. Mesophyll cells and strands of bundle-sheath cells from second leaves of 11-d-old maize seedlings were obtained by two different mechanical-isolation methods. Cross-contamination of cell preparations was determined using ribulose bisphosphate carboxylase (EC 4.1.1.39) and nitrate reductase (EC 1.6.6.1) as marker enzymes for bundle-sheath and mesophyll cells, respectively. ATP sulfurylase (EC 2.7.7.4) and adenosine 5'-phosphosulfate sulfotransferase activities were detected almost exclusively in the bundle-sheath cells, whereas GSH synthetase (EC 6.3.2.3) and cyst(e)ine, γ-glutamylcysteine, and glutathione were located predominantly in the mesophyll cells. Feeding experiments using 35Ssulfate with intact leaves indicated that cyst(e)ine was the transport metabolite of reduced sulfur from bundle-sheath to mesophyll cells. This result was corroborated by tracer experiments, which showed that isolated bundle-sheath strands fed with 35Ssulfate secreted radioactive cyst(e)ine as the sole thiol into the resuspending medium. The results presented in this paper show that assimilatory sulfate reduction is restricted to the bundle-sheath cells, whereas the formation of glutathione takes place predominantly in the mesophyll cells, with cyst(e)ine functioning as a transport metabolite between the two cell types. APSadenosine 5'-phosphosulfateAPSSTaseadenosine 5'-phosphosulfate sulfotransferaseATPSaseadenosine triphosphate sulfurylaseBSCbundle-sheath cell(s)γECγ-glutamylcysteineMCmesophyll cell(s)NRnitrate reductaseRuBPribulose-1,5-bisphosphate

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:

Suter, Marianne and 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:

30 Jan 2018 10:39

Last Modified:

30 Jan 2018 10:39

Publisher DOI:

10.1104/pp.116.4.1315

BORIS DOI:

10.7892/boris.101663

URI:

https://boris.unibe.ch/id/eprint/101663

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