% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Westhoff:58850,
      author       = {Westhoff, M. and Schneider, H. and Zimmermann, D. and
                      Mimietz, S. and Stinzing, A. and Wegner, L. H. and Kaiser,
                      W. and Krohne, G. and Shirley, St. and Jakob, P. and
                      Bamberg, E. and Bentrup, F.-W. and Zimmermann, U.},
      title        = {{T}he mechanisms of refilling of the xylem conduits and
                      bleeding of tall birch during spring},
      journal      = {Plant biology},
      volume       = {10},
      issn         = {1435-8603},
      address      = {Oxford [u.a.] :Wiley- Blackwell},
      publisher    = {Wiley-Blackwell - STM},
      reportid     = {PreJuSER-58850},
      pages        = {604 - 623},
      year         = {2008},
      note         = {Record converted from VDB: 12.11.2012},
      abstract     = {Seasonal variations in osmolality and components of xylem
                      sap in tall birch trees were determined using several
                      techniques. Xylem sap was extracted from branch and trunk
                      sections of 58 trees using the very rapid gas bubble-based
                      jet-discharge method. The 5-cm long wood pieces were taken
                      at short intervals over the entire tree height. The data
                      show that large biphasic osmolality gradients temporarily
                      exist within the conducting xylem conduits during leaf
                      emergence (up to 272 mosmol x kg(-1) at the apex). These
                      gradients (arising mainly from glucose and fructose) were
                      clearly held within the xylem conduit as demonstrated by
                      (1)H NMR imaging of intact twigs. Refilling experiments with
                      benzene, sucrose infusion, electron and light microscopy, as
                      well as (1)H NMR chemical shift microimaging provided
                      evidence that the xylem of birch represents a compartment
                      confined by solute-reflecting barriers (radial: lipid
                      linings/lipid bodies; axial: presumably air-filled spaces).
                      These features allow transformation of osmolality gradients
                      into osmotic pressure gradients. Refilling of the xylem
                      occurs by a dual mechanism: from the base (by root pressure)
                      and from the top (by hydrostatic pressure generated by
                      xylem-bound osmotic pressure). The generation of osmotic
                      pressure gradients was accompanied by bleeding. Bleeding
                      could be observed at a height of up to 21 m. Bleeding rates
                      measured at a given height decreased exponentially with
                      time. Evidence is presented that the driving force for
                      bleeding is the weight of the static water columns above the
                      bleeding point. The pressure exerted by the water columns
                      and the bleeding volume depend on the water-filling status
                      of (communicating) vessels.},
      keywords     = {Betula: physiology / Carbohydrate Metabolism /
                      Electrolytes: metabolism / Magnetic Resonance Spectroscopy /
                      Osmolar Concentration / Osmotic Pressure / Plant Roots:
                      physiology / Seasons / Trees: physiology / Water: physiology
                      / Xylem: physiology / Electrolytes (NLM Chemicals) / Water
                      (NLM Chemicals) / J (WoSType)},
      cin          = {ICG-3},
      ddc          = {580},
      cid          = {I:(DE-Juel1)ICG-3-20090406},
      pnm          = {Terrestrische Umwelt},
      pid          = {G:(DE-Juel1)FUEK407},
      shelfmark    = {Plant Sciences},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:18761499},
      UT           = {WOS:000258288200009},
      doi          = {10.1111/j.1438-8677.2008.00062.x},
      url          = {https://juser.fz-juelich.de/record/58850},
}