Long-Distance Transport of Assimilates

  • Hans Lambers
  • F. Stuart ChapinIII
  • Thijs L. Pons


The evolution of cell walls allowed plants to solve the problem of osmoregulation in freshwater environments; however, cell walls restrict motility and place constraints on the evolution of long-distance transport systems. Tissues are too rigid for a heart-pump mechanism; instead, higher plants have two systems for long-distance transport. The dead elements of the xylem allow transport of water and solutes between sites of different water potentials. That transport system is dealt with in Chapter 3 on plant water relations. The other transport system, the phloem, allows the mass flow of carbohydrates and other solutes from a source region, where the hydrostatic pressure in the phloem is relatively high, to a sink region with lower pressure.


Intermediary Cell Sieve Tube Sieve Element Minor Vein Bundle Sheath Cell 


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Hans Lambers
    • 1
  • F. Stuart ChapinIII
    • 2
  • Thijs L. Pons
    • 3
  1. 1.The University of Western AustraliaCrawleyAustralia
  2. 2.University of AlaskaFairbanksUSA
  3. 3.Utrecht UniversityThe Netherlands

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