Interaction between Phloem transport and Apoplastic Solute Concentrations

  • G. Lohaus


In addition to several other physiological functions, the apoplast is involved in phloem loading of many plant species. Therefore, apoplastic solute concentrations influence phloem transport of solutes and vice versa. For studying this relationship it is necessary to know apoplastic solute concentrations as well as that in the phloem sap. Phloem sap was collected with the laser-aphid-stylet technique. Until now this is the best possibility to collect pure phloem sap from intact plants. The analysis of apoplastic fluids is more difficult because one of the major problems in any approach to study apoplastic ion relations is the method by with apoplastic solution is obtained. Several methods to analyse apoplastic fluids have been developed but all these methods have special advantages and disadvantages. We used the infiltration-centrifugation technique and made a critical evaluation of different parameters which influence the solute concentrations in the apoplast.

Plant growth and development are dependent on translocation of photoassimilates from the sites of synthesis to the sites of consumption or storage. In addition, substantial amounts of solutes transported to the leaves in the xylem are re-translocated in the phloem. This is also true under different stress conditions like salt stress. Approximately 13–36% of the Na+ and Cl- imported into the leaves through the xylem were exported by the phloem. It is concluded that phloem transport plays an important role in controlling the solute content of a leaf.

Key words

apoplastic solute concentration infiltration-centrifugation technique laseraphid-stylet technique phloem salt stress translocation xylem 


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  1. Barlow, C.A. and Mc Cully, M.E. (1972) The ruby laser as an instrument for cutting the stylets of feeding aphids. Can. J. Zool., 50, 1497–1499.CrossRefGoogle Scholar
  2. Bauer, C.S., Hoth, S., Haga, K., Philippar, K., Aoki, N. and Hedrich, R. (2000) Differential expression and regulation of K+ channels in the maize coleoptile: molecular and biophysical analysis of the cells isolated from cortex and vasculature. Plant J., 24, 139–145.PubMedCrossRefGoogle Scholar
  3. Canny, M.J. (1990) What becomes of the transpiration stream? New Phytol., 114, 341–368.CrossRefGoogle Scholar
  4. Cosgrove, D.J. and Cleland, R.E. (1983) Solutes in the free space of growing stem tissues. Plant Physiol., 72, 326–331.PubMedGoogle Scholar
  5. Cramer, G.R., Alberico, G.J. and Schmidt, C. (1994) Salt tolerance is not associated with sodium accumulation of two maize hybrids. Aust. J. Plant Physiol., 21, 675–692.Google Scholar
  6. Dengler, N.G., Dengler, R.E., Donnelly, P.M. and Hattersley, P.W. (1994) Quantitative leaf anatomy of C3 and C4 grasses (Poaceae): Bundle sheath and mesophyll surface area relationships. Ann. Bot., 73, 241–255.CrossRefGoogle Scholar
  7. Dietz, K.J. (1997) Functions and responses of the leaf apoplast under stress. Prog. Bot., 58, 221–254.Google Scholar
  8. Downing, N. (1980) Measurements of the osmotic concentrations of stylet sap, haemolymph and honeydew from aphid under osmotic stress. J. Exp. Bot., 33, 557–573.Google Scholar
  9. Evert, R.F., Eschrich, W. and Heyser, W. (1977) Distribution and structure of the plasmodesmata in mesophyll and bundle-sheath cells of Zea mays L. Planta, 136, 77–89.Google Scholar
  10. Giaquinta, R.T. (1983) Phloem loading of sucrose. Ann. Rev. Plant Physiol., 34, 347–387.CrossRefGoogle Scholar
  11. Gouia, H., Ghorbal, M.H. and Touraine, B. (1994) Effects of NaCl on flows of N and mineral ions and on NO3 - reduction rate within whole plants of salt-sensitive bean and salt sensitive cotton. Plant Physiol., 105, 1409–1418.PubMedGoogle Scholar
  12. Greenway, H., Gunn, A., Pitman, M. and Thomas, D.A. (1965) Plant response to saline substrates. VI. Chloride, sodium, and potassium uptake and distribution within the plant during ontogenesis of Hordeum vulgare. Aust. J. Biol. Sci., 18, 525–540.Google Scholar
  13. Husted, S. and Schjoerring, J.K. (1995) Apoplastic pH and ammonium concentration in leaves of Brassica napus L. Plant Physiol., 109, 1453–1460.PubMedGoogle Scholar
  14. Jeschke, W.D., Pate, J.S. and Atkins, C.A. (1987) Partitioning of K+, Na+, Mg2+, and Ca2+ through xylem and phloem component organs and nodulated white lupin under mild salinity. J. Plant Physiol., 128, 77–93.Google Scholar
  15. Klement, Z. (1965) Method of obtaining fluid from the intercellular spaces of foliage and the fluid‘s merit as substrate for phytobacterial pathogens. Phytopathology, 55, 1033–1034.Google Scholar
  16. Lacombe, B., Pilot, G., Michard, E., Gaymard, F., Sentenac, H. and Thibaud, J.B. (2000) A skaker-like K+ channel with waek rectification is expressed in both source and sink phloem tissues of Arabidopsis. Plant Cell, 12, 837–851.PubMedCrossRefGoogle Scholar
  17. Läuchli, A. and Wieneke, J. (1979) Studies on growth and distribution of Na+, K+, and Cl- in soybean varieties differing in salt tolerance. Z. Pflanzenernähr. Bodenk., 142, 3–13.CrossRefGoogle Scholar
  18. Lessani, H. and Marschner, H. (1978) Relation between salt tolerance and long distance transport of sodium and chloride in various crop species. Aust. J. Plant Physiol., 5, 27–37.Google Scholar
  19. Lohaus, G., Hussmann, M., Pennewiss, K., Schneider, H., Zhu, J.J. and Sattelmacher, B. (2000) Solute balance of a maize (Zea mays L.) source leaf as affected by salt treatment with special emphasis on phloem retranslocation and ion leaching. J. Exp. Bot., 51, 1721–1732.PubMedCrossRefGoogle Scholar
  20. Lohaus, G., Pennewiss, K., Sattelmacher, B., Hussmann M. and Muehling, K.H. (2001) Is the infiltration-centrifugation technique appropriate for the isolation of apoplastic fluid? A critical evaluation with different plant species. Physiologia Plant., 111, 457–465.CrossRefGoogle Scholar
  21. Lohaus, G., Winter, H., Riens, B. and Heldt, H.W. (1995) Further studies of the phloem loading process in leaves of barley and spinach. The comparison of metabolite concentrations in the apoplastic compartment with those in the cytosolic compartment and in the sieve tubes. Botanica Acta, 108, 270–275.Google Scholar
  22. Luwe, M. and Heber, U. (1995) Ozone detoxification in the apoplasm and symplasm of spinach, broad bean and beech leaves at ambient and elevated concentrations of ozone in air. Planta, 197, 448–455.CrossRefGoogle Scholar
  23. Marschner, H., Kirkby, E.A. and Engels, C. (1997) Importance of cycling and recycling of mineral nutrients within plants for growth and development. Botanica Acta, 110, 265–273.Google Scholar
  24. Mimura, T., Dietz, K.-J., Kaiser, W., Schramm, M.J., Kaiser, G and Heber, U. (1992) Phosphate transport across biomembranes and cytosolic phosphate homeostasis in barley leaves. Planta, 180, 139–146.Google Scholar
  25. Mühling, K.H. and Läuchli, A. (2002a) Determination of apoplastic Na+ in intact leaves of cotton by in vivo fluorescence ratio-imaging. Funct. Plant Biol., 29, 1491–1499.CrossRefGoogle Scholar
  26. Mühling, K.H. and Läuchli, A. (2002b) Effect of salt stress on growth and cation compartmentation in leaves of two plant species differing in salt tolerance. J. Plant Physiol., 159, 137–146.CrossRefGoogle Scholar
  27. Münch, E. (1930) Die Stoffbewegungen in der Pflanze. Fischer Verlag, Jena, pp. 234.Google Scholar
  28. Munns, R., Fisher, D.B. and Tonnet, M.L. (1986) Na+ and Cl- transport in the phloem from leaves of NaCl-treated barley. Aust. J. Plant Physiol., 13, 757–66.CrossRefGoogle Scholar
  29. Nielson, K.H. and Schjoerring, J.K. (1998) regulation of apoplastic NH4 + concentration in leaves of oilseed rape. Plant Physiol., 118, 1361–1368.CrossRefGoogle Scholar
  30. Niu, X., Bressan, R.A., Hasegawa, P.M., Pardo, J.M. and Niu, X.M. (1995) Ion homeostasis in NaCl stress environments.Plant Physiol., 109, 735–742.PubMedGoogle Scholar
  31. Oertli, J.J. (1968) Extracellular salt accumulation, a possible mechanism of salt injury in plants. Agrochimica, 12, 461–469.Google Scholar
  32. Passioura, J.B. (1980) The transport of water from soil to shoot in wheat seedlings. J. Exp. Bot., 31, 333–345.CrossRefGoogle Scholar
  33. Riens, B., Lohaus, G., Winter, H. and Heldt, H.W. (1994) Production and diurnal utilization of assimilates in leaves of spinach (Spinacia oleracea L.) and barley (Hordeum vulgare L.). Planta, 192, 497–501.CrossRefGoogle Scholar
  34. Riesmeier, J.W., Willmitzer, L. and Frommer, W.B. (1992) Isolation and characterization of a sucrose carrier cDNA from spinach by functional expression in yeast. EMBO J., 11, 4705–4713.PubMedGoogle Scholar
  35. Sakurai, N. (1998) Dynamic function and regulation of apoplast in the plant body. J. Plant Res., 111, 133–148.CrossRefGoogle Scholar
  36. Sattelmacher, B. (2001) The apoplast and its significance for plant mineral nutrient. New Phytogol., 149, 167–192.CrossRefGoogle Scholar
  37. Söding, H. (1941) Über den Nachweis einer aus dem Interzellularraum von Echeveria-Blättern auswaschbaren bakteriziden Substanz. Bericht Deutsche Botanische Gesellschaft, 59, 458–466.Google Scholar
  38. Speer, M. and Kaiser, W.M. (1991) Ion relations of symplastic and apoplastic space in leaves from Spinacia oleracea L. and Pisum sativum L. under salinity. Plant Physiol., 97, 990–997.PubMedGoogle Scholar
  39. Tetlow, I.J. and Farrar, J.F. (1993) Apoplastic sugar concentration and pH in barley leaves infected with brown rust. J. Exp. Bot., 44, 929–936.CrossRefGoogle Scholar
  40. Winter, H., Robinson, D.G. and Heldt, H.W. (1993) Subcellular volumes and metabolite concentrations in barley leaves. Planta, 191, 180–190.CrossRefGoogle Scholar

Copyright information

© Springer 2007

Authors and Affiliations

  • G. Lohaus
    • 1
  1. 1.Universität Göttingen, Biochemie der PflanzeGermany

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