Modeling root hydraulic adjustment capacity in plants submitted to different stress conditions

VICTORIA VITALI; AGUSTIN YANEFF; GABRIELA AMODEO

Sierra de la Ventana

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofisica

Water flow through plants has been described as a passive diffusion mechanism based on the analogy with Ohm's law1. A continuum soil-plant-atmosphere is described in order to design a hydraulic circuit that allows describing the involved resistances through all the pathway2. In this model the transpiration demand on aerial part represents the main driving force to plant water entry by roots. It is also known that under stress conditions the driving force is not enough to interpret the circuit as a simple passive diffusion flow3. The introduction of aquaporins in the scenario creates the challenge to revisit the root intrinsic properties and its effect on water movement from soil to xylem. We performed experiments measuring root hydraulic conductivity (Lpr) as the property that better reflects the adjustment capacity to modulate water flow. We focus on discerning the root water pathways in plants submitted to a salt stress condition, seeking for capable models to explain the kinetics of water flow, in terms of Lpr and aquaporins (i.e. the enhancement or not of the transcellular pathway). Our results show that Lpr changes can highlight the intrinsic root strategy to overcome the stress situation.