Abstract
This paper describes a technique for measuring the in vivo metabolite levels in the chloroplast stroma, the cytosol, and the vacuole of spinach (Spinacia oleracea U.S.A. hybrid 424) leaves. Spinach leaves were freeze stopped and the frozen tissue was ground and lyophilized. The dry material was homogenized by sonication in a mixture of carbon tetrachloride and heptane, and fractionated by density gradient centrifugation. Measurements of the activity of marker enzymes in various subcellular compartments show the chloroplastic material mainly appearing in the lightest fractions and the cytosolic material in the middle of the gradient, whereas most of the vacuolar material is found in the heaviest fraction. Using the measured distributions of metabolites and of marker enzymes in each fraction of the gradient, the subcellular distribution of the metabolite can be calculated.
As a first application, the new fractionation technique was used to investigate the subcellular contents of malate and sucrose in spinach leaves. The results show striking diurnal changes of sucrose and malate, with both substances primarily located in the vacuolar compartment. About three times more malate is present at the end of the day than at the end of the night. The sucrose content in the vacuole falls from a maximum of 45 millimolars at the end of the day to an almost undetectable value of approximately 1 millimolar at the end of the night.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Arnon D. I. COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. Plant Physiol. 1949 Jan;24(1):1–15. doi: 10.1104/pp.24.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boller T., Kende H. Hydrolytic enzymes in the central vacuole of plant cells. Plant Physiol. 1979 Jun;63(6):1123–1132. doi: 10.1104/pp.63.6.1123. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Elbers R., Heldt H. W., Schmucker P., Soboll S., Wiese H. Measurement of the ATP/ADP ratio in mitochondria and in the extramitochondrial compartment by fractionation of freeze-stopped liver tissue in non-aqueous media. Hoppe Seylers Z Physiol Chem. 1974 Mar;355(3):378–393. doi: 10.1515/bchm2.1974.355.1.378. [DOI] [PubMed] [Google Scholar]
- Fisher D. B. Sucrose Compartmentation in the Palisade Parenchyma of Vicia faba L. Plant Physiol. 1979 Sep;64(3):481–483. doi: 10.1104/pp.64.3.481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heber U., Pon N. G., Heber M. Localization of Carboxydismutase & Triosephosphate Dehydrogenases in Chloroplasts. Plant Physiol. 1963 May;38(3):355–360. doi: 10.1104/pp.38.3.355. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Li Y. T. Studies on the glycosidases in jack bean meal. I. Isolation and properties of alpha-mannosidase. J Biol Chem. 1967 Dec 10;242(23):5474–5480. [PubMed] [Google Scholar]
- Lilley R. M., Stitt M., Mader G., Heldt H. W. Rapid fractionation of wheat leaf protoplasts using membrane filtration : the determination of metabolite levels in the chloroplasts, cytosol, and mitochondria. Plant Physiol. 1982 Oct;70(4):965–970. doi: 10.1104/pp.70.4.965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robinson S. P., Walker D. A. Rapid separation of the chloroplast and cytoplasmic fractions from intact leaf protoplasts. Arch Biochem Biophys. 1979 Sep;196(2):319–323. doi: 10.1016/0003-9861(79)90584-8. [DOI] [PubMed] [Google Scholar]
- Stitt M., Bulpin P. V., ap Rees T. Pathway of starch breakdown in photosynthetic tissues of Pisum sativum. Biochim Biophys Acta. 1978 Nov 15;544(1):200–214. doi: 10.1016/0304-4165(78)90223-4. [DOI] [PubMed] [Google Scholar]
- Stocking C. R. Chloroplast Isolation in Nonaqueous Media. Plant Physiol. 1959 Jan;34(1):56–61. doi: 10.1104/pp.34.1.56. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wirtz W., Stitt M., Heldt H. W. Enzymic determination of metabolites in the subcellular compartments of spinach protoplasts. Plant Physiol. 1980 Jul;66(1):187–193. doi: 10.1104/pp.66.1.187. [DOI] [PMC free article] [PubMed] [Google Scholar]