TY - JOUR

T1 - Xylem-transported abscisic acid: the relative importance of its mass and its concentration in the control of stomatal aperture.

AU - Gowing, D. J.

AU - Jones, H. G.

AU - Davies, W. J.

PY - 1993

Y1 - 1993

N2 - Abscisic acid (ABA) fed in pulses to the petioles of detached cherry leaves in enclosed leaf chambers, caused a reduction in leaf conductance. The degree of inhibition was analysed with respect to the amount of ABA fed and to concentration of ABA in the feeding solution. Regression analysis of the data showed both variables to have a significant effect on leaf conductance. A hypothetical maximum ABA concentration occurring in the leaf apoplast was calculated for each pulse from a simple model. This variable explained more of the variance within the data than either the amount or the applied concentration variable. A value for the rate at which ABA is removed from the apoplast is derived from the experimental data using the model. A second experiment attempted to evaluate this rate directly, by measuring the rate of catabolism of labelled ABA within the leaf. The results suggested a half-life of 36 min for the initial rate of decay. This figure is similar to that derived from the model, the importance of ABA-metabolism for the control of leaf conductance is discussed in the context of root-to-shoot communication by ABA in the xylem stream.

AB - Abscisic acid (ABA) fed in pulses to the petioles of detached cherry leaves in enclosed leaf chambers, caused a reduction in leaf conductance. The degree of inhibition was analysed with respect to the amount of ABA fed and to concentration of ABA in the feeding solution. Regression analysis of the data showed both variables to have a significant effect on leaf conductance. A hypothetical maximum ABA concentration occurring in the leaf apoplast was calculated for each pulse from a simple model. This variable explained more of the variance within the data than either the amount or the applied concentration variable. A value for the rate at which ABA is removed from the apoplast is derived from the experimental data using the model. A second experiment attempted to evaluate this rate directly, by measuring the rate of catabolism of labelled ABA within the leaf. The results suggested a half-life of 36 min for the initial rate of decay. This figure is similar to that derived from the model, the importance of ABA-metabolism for the control of leaf conductance is discussed in the context of root-to-shoot communication by ABA in the xylem stream.

KW - Prunus avium × pseudocerasus L. • Rosaceae • cherry • leaf conductance • root signal • ABA metabolism

U2 - 10.1111/j.1365-3040.1993.tb00892.x

DO - 10.1111/j.1365-3040.1993.tb00892.x

M3 - Journal article

VL - 16

SP - 453

EP - 459

JO - Plant, Cell and Environment

JF - Plant, Cell and Environment

SN - 0140-7791

IS - 4

ER -