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. 1969 Jan;44(1):7–14. doi: 10.1104/pp.44.1.7

Compartmentation of Malate in Relation to Ion Absorption in Beet

C B Osmond a,1, George G Laties a
PMCID: PMC396031  PMID: 16657035

Abstract

Malate in beet discs treated in different salt solutions was labeled by a 30 min pulse of 14CO2, and subsequent changes in specific activity were followed for several hr. In treatments which resulted in net acid synthesis in response to excess cation absorption, malate specific activity fell slowly after removal of 14CO2. In solutions where no net acid synthesis occurred, and from which cation and anion were absorbed equally, malate specific activity fell rapidly when 14CO2 was removed. The foregoing suggests that the net synthesis of organic acids in response to excess cation absorption leads to the removal of organic anions from cytoplasmic metabolic pools as counter-ions in salt transport to the vacuole.

The latter hypothesis was further examined by direct measurement of the distribution of labeled malate between cytoplasm and vacuole using the wash-exchange method of compartmental analysis, previously described for inorganic ions. The method satisfied the criterion of exchange specificity necessary for this purpose. Much higher retention of label in the cytoplasm was observed in KCl solutions (no net synthesis) than in K2SO4 solutions (net synthesis) after 3 hr 14CO2 fixation and subsequent wash-exchange. The observed distribution is consistent with the rapid removal of organic anions to the vacuole during net acid synthesis. The significance of organic acid transport in relation to metabolism is discussed.

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Selected References

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

  1. Epstein E., Rains D. W., Elzam O. E. RESOLUTION OF DUAL MECHANISMS OF POTASSIUM ABSORPTION BY BARLEY ROOTS. Proc Natl Acad Sci U S A. 1963 May;49(5):684–692. doi: 10.1073/pnas.49.5.684. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Hiatt A. J. Relationship of Cell Sap pH to Organic Acid Change During Ion Uptake. Plant Physiol. 1967 Feb;42(2):294–298. doi: 10.1104/pp.42.2.294. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. JACKSON P. C., ADAMS H. R. Cation-anion balance during potassium and sodium absorption by barley roots. J Gen Physiol. 1963 Jan;46:369–386. doi: 10.1085/jgp.46.3.369. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Joshi G., Dolan T., Gee R., Saltman P. Sodium Chloride Effect on Dark Fixation of CO(2) by Marine & Terrestrial Plants. Plant Physiol. 1962 May;37(3):446–449. doi: 10.1104/pp.37.3.446. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Laties G. G. The Onset of Tricarboxylic Acid Cycle Activity with Aging in Potato Slices. Plant Physiol. 1964 Jul;39(4):654–663. doi: 10.1104/pp.39.4.654. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lips S. H., Beevers H. Compartmentation of Organic Acids in Corn Roots II. The Cytoplasmic Pool of Malic Acid. Plant Physiol. 1966 Apr;41(4):713–717. doi: 10.1104/pp.41.4.713. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Lips S. H., Beevers H. Compartmentation of organic acids in corn roots I. Differential labeling of 2 malate pools. Plant Physiol. 1966 Apr;41(4):709–712. doi: 10.1104/pp.41.4.709. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Maclennan D. H., Beevers H., Harley J. L. 'Compartmentation' of acids in plant tissues. Biochem J. 1963 Nov;89(2):316–327. doi: 10.1042/bj0890316. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Osmond C. B., Laties G. G. Interpretation of the dual isotherm for ion absorption in beet tissue. Plant Physiol. 1968 May;43(5):747–755. doi: 10.1104/pp.43.5.747. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Poole R. J. The influence of the intracellular potential on potassium uptake by beetroot tissue. J Gen Physiol. 1966 Jan;49(3):551–563. doi: 10.1085/jgp.49.3.551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Steer B. T., Beevers H. Compartmentation of Organic Acids in Corn Roots. III. Utilization of Exogenously Supplied Acids. Plant Physiol. 1967 Sep;42(9):1197–1201. doi: 10.1104/pp.42.9.1197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ting I. P., Dugger W. M. CO(2) Fixation in Opuntia Roots. Plant Physiol. 1966 Mar;41(3):500–505. doi: 10.1104/pp.41.3.500. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Torii K., Laties G. G. Dual mechanisms of ion uptake in relation to vacuolation in corn roots. Plant Physiol. 1966 May;41(5):863–870. doi: 10.1104/pp.41.5.863. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. WALKER D. A. Physiological studies on acid metabolism. 4. Phosphoenolpyruvic carboxylase activity in extracts of Crassulacean plants. Biochem J. 1957 Sep;67(1):73–79. doi: 10.1042/bj0670073. [DOI] [PMC free article] [PubMed] [Google Scholar]

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