Modelagem das vias de transporte hídrico da raiz em plantas vasculares : análogo elétrico

Abstract

The basic functions of the root are to sustain the plant and absorb water and nutrients from the soil. The water consumption of the plant is necessary for biochemical processes and consequent to cellular metabolic activities. One way to understand the fluid dynamics of roots is to model the system by means of an analogue to the electric circuit, consisting primarily of resistors and capacitors associated. An equivalent electrical circuit was built in QUCS computer program, which allows modeling and simulating the fluid flow in the root, applying analogous Kirchhoff laws. Experimental data for two species of vascular plants (wheat and corn) were used in order to establish the stages of simulation, calibration and validation of modeling. The methodology allows further in detailing the root of vascular plants, to characterize the components and flow paths, and distribute the functions of components in the prospect of emerging physiological properties of this structure. One for the steady state and other for the oscillatory regime: two simulations for the roots of wheat and corn were made. In the stationary system, there is a reversal of the supremacy of apoplastic flow with respect to symplastictransmembrane flow at an intermediate point of the cortex due to the interruption of the flow through the apoplastic streaks of Caspary. In the oscillatory regime, there is a lag of the maximum signal toward the endoderm, ie, the gap increases with the distance from the sinusoidal source. The explicit modeling an expected due to the flow resistance and the characteristic times of charging and discharging of the capacitors behavior, however, is not described in the literature.