Modelling the impact of heterogeneous rootzone water distribution on the regulation of transpiration by hormone transport and/or hydraulic pressures

Huber, Katrin; Vereecken, Harry; Schröder, Natalie; Javaux, Mathieu; Dodd, Ian C.; Vanderborght, Jan

doi:10.1007/s11104-014-2188-4

Journal Article

FZJ-2014-03721

Modelling the impact of heterogeneous rootzone water distribution on the regulation of transpiration by hormone transport and/or hydraulic pressures

Huber, K. (Corresponding Author)FZJ* ; Vanderborght, J.FZJ* ; Javaux, M.FZJ* ; Schröder, N.FZJ* ; Dodd, I. C. ; Vereecken, H.FZJ*

2014
Springer Science + Business Media B.V Dordrecht [u.a.]

Plant and soil 384(1-2), 93-112 (2014) [10.1007/s11104-014-2188-4]

This record in other databases:

Please use a persistent id in citations: doi:10.1007/s11104-014-2188-4

Abstract: 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.

Classification: