TY  - JOUR
AU  - Huber, Katrin
AU  - Vanderborght, Jan
AU  - Javaux, Mathieu
AU  - Schröder, Natalie
AU  - Dodd, Ian C.
AU  - Vereecken, Harry
TI  - Modelling the impact of heterogeneous rootzone water distribution on the regulation of transpiration by hormone transport and/or hydraulic pressures
JO  - Plant and soil
VL  - 384
IS  - 1-2
SN  - 1573-5036
CY  - Dordrecht [u.a.]
PB  - Springer Science + Business Media B.V
M1  - FZJ-2014-03721
SP  - 93-112
PY  - 2014
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000344336200008
DO  - DOI:10.1007/s11104-014-2188-4
UR  - https://juser.fz-juelich.de/record/154373
ER  -