%0 Journal Article
%A Huber, Katrin
%A Vanderborght, Jan
%A Javaux, Mathieu
%A Schröder, Natalie
%A Dodd, Ian C.
%A Vereecken, Harry
%T Modelling the impact of heterogeneous rootzone water distribution on the regulation of transpiration by hormone transport and/or hydraulic pressures
%J Plant and soil
%V 384
%N 1-2
%@ 1573-5036
%C Dordrecht [u.a.]
%I Springer Science + Business Media B.V
%M FZJ-2014-03721
%P 93-112
%D 2014
%X Aims: A simulation model to demonstrate that soil water potential can regulate transpiration, by influencing leaf water potential and/or inducing root production of chemical signals that are transported to the leaves.Methods: Signalling impacts on the relationship between soil water potential and transpiration were simulated by coupling a 3D model for water flow in soil, into and through roots (Javaux et al.2008) with a model for xylem transport of chemicals (produced as a function of local root water potential). Stomatal conductance was regulated by simulated leaf water potential (H) and/or foliar chemical signal concentrations (C; H+C). Split-root experiments were simulated by varying transpiration demands and irrigation placement.Results: While regulation of stomatal conductance by chemical transport was unstable and oscillatory, simulated transpiration over time and root water uptake from the two soil compartments were similar for both H and H+C regulation. Increased stomatal sensitivity more strongly decreased transpiration, and decreased threshold root water potential (below which a chemical signal is produced) delayed transpiration reduction. Conclusions: Although simulations with H+C regulation qualitatively reproduced transpiration of plants exposed to partial rootzone drying (PRD), long-term effects seemed negligible. Moreover, most transpiration responses to PRD could be explained by hydraulic signalling alone.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000344336200008
%R 10.1007/s11104-014-2188-4
%U https://juser.fz-juelich.de/record/154373