Premium
Co‐permeability of 3 H‐labelled water and 14 C‐labelled organic acids across isolated Prunus laurocerasus cuticles: effect of temperature on cuticular paths of diffusion
Author(s) -
Schreiber L.
Publication year - 2002
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.2002.00897.x
Subject(s) - benzoic acid , chemistry , arrhenius equation , wax , permeability (electromagnetism) , nuclear chemistry , chromatography , membrane , stereochemistry , activation energy , analytical chemistry (journal) , organic chemistry , biochemistry
Co‐permeability of 3 H‐labelled water and 14 C‐labelled benzoic acid or 2,4‐dichlorophenoxyacetic acid across isolated cuticular membranes of Prunus laurocerasus L. was measured at temperatures ranging from 15 to 50 °C. The water and benzoic acid permeances were highly correlated over the whole temperature range investigated, whereas water and 2,4‐dichlorophenoxyacetic acid permeances were only correlated between 15 and 30 °C. The activation energies of cuticular permeability calculated from Arrhenius plots were 40 kJ mol −1 for water and benzoic acid and 115 kJ mol −1 for 2,4‐dichlorophenoxyacetic acid. The slopes of the Arrhenius plots of 2,4‐dichlorophenoxyacetic acid were linear between 15 and 50 °C, whereas pronounced phase transitions around 30 °C were observed for water and benzoic acid permeability. However, with isolated polymer matrix membranes, where cuticular waxes forming the transport‐limiting barrier of cuticles have been extracted, phase transitions were not observed for water and benzoic acid. It is concluded that temperatures above 30 °C caused structural changes in the transport‐limiting barrier of the cuticles leading to additional paths of diffusion for water and benzoic acid but not for 2,4‐dichlorophenoxyacetic acid.