Abstract
The green-fruited Lycopersicon hirsutum Humb. and Bonpl. accumulated sucrose to concentrations of about 118 micromoles per gram fresh weight during the final stages of development. In comparison, Lycopersicon esculentum Mill. cultivars contained less than 15 micromoles per gram fresh weight of sucrose at the ripe stage. Glucose and fructose levels remained relatively constant throughout development in L. hirsutum at 22 to 50 micromoles per gram fresh weight each. Starch content was low even at early stages of development, and declined further with development. Soluble acid invertase (EC 3.2. 1.26) activity declined concomitant with the rise in sucrose content. Acid invertase activity, which was solubilized in 1 molar NaCl (presumably cell-wall bound), remained constant throughout development (about 3 micromoles of reducing sugars (per gram fresh weight) per hour. Sucrose phosphate synthase (EC 2.4.1.14) activity was present at about 5 micromoles of sucrose (per gram fresh weight) per hour even at early stages of development, and increased sharply to about 40 micromoles of sucrose (per gram fresh weight) per hour at the final stages of development studied, parallel to the rise in sucrose content. In comparison, sucrose phosphate synthase activity in L. esculentum remained low throughout development. The possible roles of the sucrose metabolizing enzymes in determining sucrose accumulation are discussed.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Damon S., Hewitt J., Nieder M., Bennett A. B. Sink Metabolism in Tomato Fruit : II. Phloem Unloading and Sugar Uptake. Plant Physiol. 1988 Jul;87(3):731–736. doi: 10.1104/pp.87.3.731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Giaquinta R. T. Sucrose translocation and storage in the sugar beet. Plant Physiol. 1979 May;63(5):828–832. doi: 10.1104/pp.63.5.828. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hatch M. D., Glasziou K. T. Sugar Accumulation Cycle in Sugar Cane. II. Relationship of Invertase Activity to Sugar Content & Growth Rate in Storage Tissue of Plants Grown in Controlled Environments. Plant Physiol. 1963 May;38(3):344–348. doi: 10.1104/pp.38.3.344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hatch M. D., Sacher J. A., Glasziou K. T. Sugar Accumulation Cycle in Sugar Cane. I. Studies on Enzymes of the Cycle. Plant Physiol. 1963 May;38(3):338–343. doi: 10.1104/pp.38.3.338. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Helmerhorst E., Stokes G. B. Microcentrifuge desalting: a rapid, quantitative method for desalting small amounts of protein. Anal Biochem. 1980 May 1;104(1):130–135. doi: 10.1016/0003-2697(80)90287-0. [DOI] [PubMed] [Google Scholar]
- Hubbard N. L., Huber S. C., Pharr D. M. Sucrose Phosphate Synthase and Acid Invertase as Determinants of Sucrose Concentration in Developing Muskmelon (Cucumis melo L.) Fruits. Plant Physiol. 1989 Dec;91(4):1527–1534. doi: 10.1104/pp.91.4.1527. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leigh R. A., Rees T., Fuller W. A., Banfield J. The location of acid invertase activity and sucrose in the vacuoles of storage roots of beetroot (Beta vulgaris). Biochem J. 1979 Mar 15;178(3):539–547. doi: 10.1042/bj1780539. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lingle S. E., Dunlap J. R. Sucrose Metabolism in Netted Muskmelon Fruit during Development. Plant Physiol. 1987 Jun;84(2):386–389. doi: 10.1104/pp.84.2.386. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Van Handel E. Direct microdetermination of sucrose. Anal Biochem. 1968 Feb;22(2):280–283. doi: 10.1016/0003-2697(68)90317-5. [DOI] [PubMed] [Google Scholar]
- Yelle S., Hewitt J. D., Robinson N. L., Damon S., Bennett A. B. Sink Metabolism in Tomato Fruit : III. Analysis of Carbohydrate Assimilation in a Wild Species. Plant Physiol. 1988 Jul;87(3):737–740. doi: 10.1104/pp.87.3.737. [DOI] [PMC free article] [PubMed] [Google Scholar]