Articles
ROOT SIGNALS AFFECT WATER USE EFFICIENCY AND SHOOT GROWTH
Article number
427_1
Pages
2 – 14
Language
English
Abstract
Under conditions of soil water deficiency plant water relations and chemical signals affect stomatal conductance of grapevine leaves.
The abscisic acid (ABA) concentration is shown to increase in stressed roots and ABA is transported in xylem to the leaves where it reduces photosynthesis slightly whereas transpiration is reduced more severely.
In experiments with glasshouse-grown and outdoor-grown twin-root vines this leads to an increase of the water use efficiency.
Root signals appear to inhibit vegetative growth as well: at a high leaf water status shoot growth, leaf number and leaf area are significantly reduced, increasing the fruit-to-pruning weight ratio.
A model integrating hydraulic and chemical signalling in water stressed plants (Tardieu and Davies, Plant, Cell and Environ. 16:341–349, 1993) is presented to interpret the results obtained with grapevines.
It is concluded that chemical root-to-shoot communication is an integral part of adaptation processes leading to a reduction of water loss before the water status of grapevine declines.
The abscisic acid (ABA) concentration is shown to increase in stressed roots and ABA is transported in xylem to the leaves where it reduces photosynthesis slightly whereas transpiration is reduced more severely.
In experiments with glasshouse-grown and outdoor-grown twin-root vines this leads to an increase of the water use efficiency.
Root signals appear to inhibit vegetative growth as well: at a high leaf water status shoot growth, leaf number and leaf area are significantly reduced, increasing the fruit-to-pruning weight ratio.
A model integrating hydraulic and chemical signalling in water stressed plants (Tardieu and Davies, Plant, Cell and Environ. 16:341–349, 1993) is presented to interpret the results obtained with grapevines.
It is concluded that chemical root-to-shoot communication is an integral part of adaptation processes leading to a reduction of water loss before the water status of grapevine declines.
Publication
Authors
H. Düring, P.R. Dry, B.R. Loveys
Keywords
root signal, hydraulic communication, water use efficiency, vegetative growth, water stress, adaptation to drought, stomatal conductance, water potential, abscisic acid
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