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Registro Completo |
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Biblioteca(s): |
Embrapa Pantanal. |
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Data corrente: |
04/05/2001 |
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Data da última atualização: |
30/03/2017 |
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Autoria: |
WISTUBA, N.; REICH, R.; WAGNER, H. J.; ZHU, J. J.; SCHNEIDER, H.; BENTRUP, F. W.; HAASE, A.; ZIMMERMANN, U. |
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Título: |
Xylem flow and its driving forces in a tropical liana: concomitant flow-sensitive NMR imaging and pressure probe measurements. |
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Ano de publicação: |
2000 |
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Fonte/Imprenta: |
Plant Biology, v.2, n.6, p.579-582, 2000. |
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Idioma: |
Inglês |
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Conteúdo: |
Flow-sensitive NMR imaging and pressure probe techniques were used for measuring xylem water flow and its driving forces (i.e., xylem pressure as well as cell turgor and osmotic pressure gradients) in a tropical liana, Epipremnun aureum. Selection of tall specimens allowed continuous and simultaneous measurements of all parameters at various distances from the root under diurnally changing environmental conditions. Well hydrated plants exhibited exactly linearly correlated dynamics changes in xylem tension and flow velocity. Concomitant multiple-probe insertions along the plant shoot revealed xylem and turgor pressure gradients with changing magnitudes due to environmental changes and plant orientation (upright, apex-down, or horizontal). The data suggest that in upright and - to a lesser extent - in horizontal plants the transpirational water loss by the cells towards the apex during the day is not fully compensated by water uptake throught the night. Thus, longitudinal cellular osmotic pressure gradients exist. Due to the tight hydraulic coupling of the xylem and the tissue cells these gradients represent (besides the transpiration-induced tension in the xylem) an additional tension component for anti-gravitional water movement from the roots throught the vessels to the apex. |
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Palavras-Chave: |
Cell osmotic; Diurnal change; NMR; Plant; Tropical liana; Xylem flow. |
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Thesagro: |
Planta. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02071naa a2200289 a 4500
001 1806256
005 2017-03-30
008 2000 bl --- 0-- u #d
100 1 $aWISTUBA, N.
245 $aXylem flow and its driving forces in a tropical liana$bconcomitant flow-sensitive NMR imaging and pressure probe measurements.
260 $c2000
520 $aFlow-sensitive NMR imaging and pressure probe techniques were used for measuring xylem water flow and its driving forces (i.e., xylem pressure as well as cell turgor and osmotic pressure gradients) in a tropical liana, Epipremnun aureum. Selection of tall specimens allowed continuous and simultaneous measurements of all parameters at various distances from the root under diurnally changing environmental conditions. Well hydrated plants exhibited exactly linearly correlated dynamics changes in xylem tension and flow velocity. Concomitant multiple-probe insertions along the plant shoot revealed xylem and turgor pressure gradients with changing magnitudes due to environmental changes and plant orientation (upright, apex-down, or horizontal). The data suggest that in upright and - to a lesser extent - in horizontal plants the transpirational water loss by the cells towards the apex during the day is not fully compensated by water uptake throught the night. Thus, longitudinal cellular osmotic pressure gradients exist. Due to the tight hydraulic coupling of the xylem and the tissue cells these gradients represent (besides the transpiration-induced tension in the xylem) an additional tension component for anti-gravitional water movement from the roots throught the vessels to the apex.
650 $aPlanta
653 $aCell osmotic
653 $aDiurnal change
653 $aNMR
653 $aPlant
653 $aTropical liana
653 $aXylem flow
700 1 $aREICH, R.
700 1 $aWAGNER, H. J.
700 1 $aZHU, J. J.
700 1 $aSCHNEIDER, H.
700 1 $aBENTRUP, F. W.
700 1 $aHAASE, A.
700 1 $aZIMMERMANN, U.
773 $tPlant Biology$gv.2, n.6, p.579-582, 2000.
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Registro original: |
Embrapa Pantanal (CPAP) |
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