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. 1980 Sep;66(3):422–427. doi: 10.1104/pp.66.3.422

Uptake and Subcellular Compartmentation of Gibberellin A1 Applied to Leaves of Barley and Cowpea 1

John B Ohlrogge 1,2, Jose L García-Martínez 1,3, David Adams 1, Lawrence Rappaport 1
PMCID: PMC440646  PMID: 16661448

Abstract

The uptake and subcellular accumulation of gibberellin A1 (GA1) by leaves and protoplasts of barley (cv. Numar) and cowpea (cv. Blackeye pea No. 5) were investigated.

Uptake of GA1 by cowpea leaves is optimal at pH 5.8 and occurs by a saturable, probably carrier-mediated process having a half-maximal velocity at 10 to 20 micromolar. Uptake by both barley and cowpea leaves is inhibited by low temperature (+4 C) and the metabolic inhibitors 2,4-dinitrophenol and azide and is stimulated by ATP. Mesophyll protoplasts isolated from leaves fed radioactive GA1 retain 20 to 80% of the radioactivity incorporated by excised leaves.

The subcellular localization of the [3H]GA was determined by lysing protoplasts and separating subcellular organelles by density gradient centrifugation. Less than 5% of the incorporated [3H]GA was found associated with chloroplasts, mitochondria, nuclei, or other organelles or membranes with densities in sucrose gradients greater than 1.15 grams per cubic centimeter. Fifty to 100% of the [3H]GA was found in vacuoles. Isolated vacuoles were judged to be free of contamination by cytoplasm using phosphoenolpyruvate carboxylase as a marker enzyme. Osmotic breakage of vacuoles or protoplasts released > 95% of the [3H]GA, suggesting that GA is associated with the vacuolar sap rather than with the tonoplast membrane.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Beier H., Bruening G. The use of an abrasive in the isolation of cowpea leaf protoplasts which support the multiplication of cowpea mosaic virus. Virology. 1975 Mar;64(1):272–276. doi: 10.1016/0042-6822(75)90099-9. [DOI] [PubMed] [Google Scholar]
  2. 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]
  3. Evans A., Smith H. Localization of phytochrome in etioplasts and its regulation in vitro of gibberellin levels. Proc Natl Acad Sci U S A. 1976 Jan;73(1):138–142. doi: 10.1073/pnas.73.1.138. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Frearson E. M., Power J. B., Cocking E. C. The isolation, culture and regeneration of Petunia leaf protoplasts. Dev Biol. 1973 Jul;33(1):130–137. doi: 10.1016/0012-1606(73)90169-3. [DOI] [PubMed] [Google Scholar]
  5. Kojima M., Poulton J. E., Thayer S. S., Conn E. E. Tissue Distributions of Dhurrin and of Enzymes Involved in Its Metabolism in Leaves of Sorghum bicolor. Plant Physiol. 1979 Jun;63(6):1022–1028. doi: 10.1104/pp.63.6.1022. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lorimer G. H., Badger M. R., Andrews T. J. D-Ribulose-1,5-bisphosphate carboxylase-oxygenase. Improved methods for the activation and assay of catalytic activities. Anal Biochem. 1977 Mar;78(1):66–75. doi: 10.1016/0003-2697(77)90009-4. [DOI] [PubMed] [Google Scholar]
  7. Nishimura M., Graham D., Akazawa T. Isolation of intact chloroplasts and other cell organelles from spinach leaf protoplasts. Plant Physiol. 1976 Sep;58(3):309–314. doi: 10.1104/pp.58.3.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Rubery P. H., Sheldrake A. R. Effect of pH and surface charge on cell uptake of auxin. Nat New Biol. 1973 Aug 29;244(139):285–288. doi: 10.1038/newbio244285a0. [DOI] [PubMed] [Google Scholar]
  9. Silk W. K., Jones R. L. Growth and gibberellin a(1) metabolism in excised lettuce hypocotyls. Plant Physiol. 1977 Feb;59(2):211–216. doi: 10.1104/pp.59.2.211. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Simcox P. D., Dennis D. T., West C. A. Kaurene synthetase from plastids of developing plant tissues. Biochem Biophys Res Commun. 1975 Sep 2;66(1):166–172. doi: 10.1016/s0006-291x(75)80309-3. [DOI] [PubMed] [Google Scholar]
  11. Wong K. F., Davies D. D. Regulation of phosphoenolpyruvate carboxylase of Zea mays by metabolites. Biochem J. 1973 Mar;131(3):451–458. doi: 10.1042/bj1310451. [DOI] [PMC free article] [PubMed] [Google Scholar]

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