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Cavitation in plants at low temperature: is sap transport limited by the tensile strength of water as expected from Briggs’ Z‐tube experiment?
Author(s) -
Cochard Hervé,
Barigah Têtè,
Herbert Eric,
Caupin Frédéric
Publication year - 2007
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2006.01947.x
Subject(s) - cavitation , xylem , tube (container) , water transport , ultimate tensile strength , cohesion (chemistry) , chemistry , materials science , composite material , water flow , mechanics , geotechnical engineering , horticulture , geology , physics , biology , organic chemistry
Summary• Xylem cavitation in plants is thought to be caused by a loss of adhesion at the conduit wall surface because a rupture in the body of the water column was implicitly ruled out by an experiment by Lyman J. Briggs with Z‐tube capillaries. However, Briggs reported a drastic increase in cavitation pressure of water below 5°C which, if it were also true in xylem conduits, would suggest that water transport in plants could be limited by water cohesion at low temperature. • In this study we have repeated Briggs’ experiment using stem segments. Xylem vulnerability curves were obtained with a centrifuge technique at 1, 25 and 50°C on yew ( Taxus baccata ). • Contrary to Briggs’ finding, vulnerability to cavitation, measured as per cent loss conductance, did not increase sharply at 1°C and was even less than at 25°C and 50°C. Moreover, the onset of cavitation in yew at 1°C was measured at a much more negative pressure than Briggs’ value. • This points out an artefact in Brigg's experiment at low temperature possibly related to imperfections in the tube walls which act as cavitation nuclei.