Biologia Plantarum

, Volume 52, Issue 3, pp 502–506 | Cite as

Changes of pH of solutions during perfusion through stem segments: further evidence for hydrogel regulation of xylem hydraulic properties?

  • A. Gascó
  • E. Gortan
  • S. Salleo
  • A. Nardini
Original Papers


Changes in hydraulic conductivity (Kh) and pH were measured in stem segments of laurel (Laurus nobilis L.) during perfusion with iso-osmotic solutions of KCl, NaCl and sucrose. Sucrose had no effect on Kh while 100 mM NaCl or KCl induced up to 22 and 35 % increase of Kh with respect to deionized water, respectively. Increases in Kh were accompanied by a sharp drop in pH from 6.0 (inlet solution) to 5.0 (outlet solution). The same effect was observed with both KCl and NaCl solutions but not in the case of sucrose. Also, similar changes of Kh and pH were observed for stems killed after immersion in hot water. Our results might provide further evidence for ion-mediated regulation of xylem hydraulic conductivity based on the hydrogel properties of pectins at the pit membrane level.

Additional key words

pit membranes potassium hydraulic conductivity Laurus nobilis



hydraulic conductivity


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Brodribb, T.J., Holbrook, N.M., Gutierrez, M.V.: Hydraulic and photosynthetic co-ordination in seasonally dry tropical forest trees.-Plant Cell Environ. 25: 1435–1444, 2002.CrossRefGoogle Scholar
  2. Cochard, H., Bodet, C., Améglio, T., Cruiziat, P.: Cryo-scanning electron microscopy observations of vessel contents during transpiration in walnut petioles. Facts or artifacts?-Plant Physiol. 124: 1191–1202, 2000.PubMedCrossRefGoogle Scholar
  3. Dähnert, K., Huster, D.: Comparison of the Poisson-Boltzmann model and the Donnan equilibrium of a polyelectrolyte in salt solution.-J. Colloid Interface Sci. 215: 131–139, 1999.PubMedCrossRefGoogle Scholar
  4. De Boer, A.H., Volkov, V.: Logistics of water and salt transport through the plant: structure and functioning of the xylem.-Plant Cell Environ. 26: 87–101, 2003.CrossRefGoogle Scholar
  5. Fahn, A.: Plant Anatomy.-Butterworth-Heinemann, Oxford 1990.Google Scholar
  6. Gascó, A., Nardini, A., Gortan, E., Salleo, S.: Ion-mediated increase in the xylem hydraulic conductivity: role of pits and consequences for the impact of cavitation on water transport in plants.-Plant Cell Environ. 29: 1946–1955, 2006.PubMedCrossRefGoogle Scholar
  7. Gascó, A., Salleo, S., Gortan, E., Nardini, A.: Seasonal changes in the ion-mediated increase of xylem hydraulic conductivity in stems of three evergreens: any functional role?-Physiol. Plant. 129: 597–606, 2007.CrossRefGoogle Scholar
  8. Gillet, C., Voué, M., Cambier, P.: Site-specific counterion binding and pectic chains conformational transitions in the Nitella cell wall.-J. exp. Bot. 49: 797–805, 1998.CrossRefGoogle Scholar
  9. Gollan, T., Schurr, U., Schulze, E.-D.: Stomatal response to drying soil in relation to changes in the xylem sap composition of Helianthus annuus. I. The concentration of cations, anions, amino acids and the pH of xylem sap.-Plant Cell Environ. 15: 551–559, 1992.CrossRefGoogle Scholar
  10. Goodger, J.Q.D., Sharp, R.E., Marsh, E.L., Schachtman, D.P.: Relationships between xylem sap constituents and leaf conductance of well-watered and water-stressed maize across three xylem sampling techniques.-J. exp. Bot. 56: 2389–2400, 2005.PubMedCrossRefGoogle Scholar
  11. Herdel, K., Schmidt, P., Feil, R., Mohr, A., Schurr, U.: Dynamics of concentration and nutrient fluxes in the xylem of Ricinus communis — diurnal course, impact of nutrient availability and nutrient uptake.-Plant Cell Environ. 24: 41–52, 2001.CrossRefGoogle Scholar
  12. Huber, B., Metz, W.: Über die Bedeutung des Hoftüpfelverschlusses für die axiale Wasserleitfähigkeit von Nadelhölzern.-Planta 51: 645–672, 1958.CrossRefGoogle Scholar
  13. Ryden, P., MacDougall, A.J., Tibbits, C.W., Ring S.G.: Hydration of pectic polysaccharides.-Biopolymers 54: 398–405, 2000.PubMedCrossRefGoogle Scholar
  14. Salleo, S., Lo Gullo, M.A., De Paoli, D., Zippo M.: Xylem recovery from cavitation-induced embolism in young plants of Laurus nobilis: a possible mechanism.-New Phytol. 132: 47–56, 1996.CrossRefGoogle Scholar
  15. Salleo S., Lo Gullo, M.A., Trifilò, P., Nardini, A.: New evidence for a role of vessel-associated cells and phloem in the rapid xylem refilling of cavitated stems of Laurus nobilis L.-Plant Cell Environ. 27: 1064–1075, 2004.CrossRefGoogle Scholar
  16. Schill, V., Hartung, W., Orthen, B., Weiselseel, M.H.: The xylem sap of maple (Acer platanoides L.) trees — sap obtained by a novel method shows changes with season and height.-J. exp. Bot. 47: 123–133, 1996.CrossRefGoogle Scholar
  17. Siebrecht, S., Herdel, K., Schurr, U., Tischner, R.: Nutrient translocation in the xylem of poplar — diurnal variations and spatial distribution along the shoot axis.-Planta 217: 783–793, 2003.PubMedCrossRefGoogle Scholar
  18. Sperry, J.S., Donnelly, J.R., Tyree, M.T.: A method of measuring hydraulic conductivity and embolism in xylem.-Plant Cell Environ. 11: 35–40, 1988.CrossRefGoogle Scholar
  19. Thakur, B.R., Singh, A.K., Handa, A.K.: Chemistry and use of pectin — a review.-Crit. Rev. Food Sci. Nutr. 37: 47–73, 1997.PubMedCrossRefGoogle Scholar
  20. Tyree, M.T., Salleo, S., Nardini, A., Lo Gullo, M.A., Mosca, R.: Refilling of embolized vessels in young stems of laurel. Do we need a new paradigm?-Plant Physiol. 120: 11–21, 1999.CrossRefGoogle Scholar
  21. Tyree, M.T., Yang S.: Hydraulic conductivity recovery versus water pressure in xylem of Acer saccharum.-Plant Physiol. 100: 669–676, 1992.PubMedCrossRefGoogle Scholar
  22. Van Ieperen, W., Van Meeteren, U., Van Gelder, H.: Fluid ionic composition influences hydraulic conductance of xylem conduits.-J. exp. Bot. 51: 769–776, 2000.PubMedCrossRefGoogle Scholar
  23. Willats, W.G.T., McCartney, L., Mackie, W., Knox, J.P.: Pectin: cell biology and prospects for functional analysis.-Plant mol. Biol. 47: 9–27, 2001.PubMedCrossRefGoogle Scholar
  24. Zimmermann, M.H.: Hydraulic architecture of some diffuse-porous trees.-Can. J. Bot. 56: 2286–2295, 1978.CrossRefGoogle Scholar
  25. Zwieniecki, M.A., Melcher, P.J., Holbrook, N.M.: Hydrogel control of xylem hydraulic resistance in plants.-Science 291: 1059–1062, 2001.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Dipartimento di BiologiaUniversità di TriesteTriesteItalia

Personalised recommendations