
TY  - JOUR
A1  - Lovisolo, Claudio 
A1  - Hartung, Wolfram 
A1  - Schubert, Andrea 
T1  - Whole-plant hydraulic conductance and root-to-shoot flow of abscisic acid are independently affected by water stress in grapevines
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 2002
VL  - 29
IS  - 11
SP  - 1349
EP  - 1356
KW  - ABA, abscisic acid, cavitation, embolism, hydraulic conductivity, root-to-shoot signal, split-root, stomatal conductance, Vitis vinifera L., water stress.
UR  - https://doi.org/10.1071/FP02079 
N2  - In order to investigate whether plant hydraulic conductance (gplant) is reduced under drought conditions via an ABA-related mechanism, a water-stress experiment was carried out using split-rooted grapevines. In addition, inversion of shoot growth orientation was imposed to reduce gplant independently of soil water availability, and thus of the putative ABA root-generated stress message. As expected, water stress imposed on split-roots affected ABA accumulation. ABA drought-stress message negatively affected stomatal conductance (gs) and transpiration (E), but modified neither leaf or stem water potentials (&#936;leaf and &#936;stem, respectively), nor gplant. When gplant was reduced in split-rooted, shoot-inverted (s-r/s-i) grapevines, &#936;leaf and &#936;stem decreased, without changes in ABA accumulation, gs and E. The ABA drought-stress message did not modify gplant, nor did gplant (impaired by shoot-growth inversion) decrease ABA delivery to the leaves. However, leaf growth was depressed in s-r/s-i grapevines. The fact that no interaction between ABA stress messages (caused by split-root technique) and hydraulic constraints to sap flow (caused by shoot inversion) was necessary to impair leaf growth suggests that the targets of ABA and hydraulic-limitation effects on leaf expansion are not the same. 
ER  -

