The significance of roots as hydraulic rheostats

CHRISTOPHE MAUREL, THIERRY SIMONNEAU, MOIRA SUTKA

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Lugar: OXFORD; Año: 2010 vol. 61 p. 3191 - 3198

0022-0957

Roots are the primary sites of water uptake by plants. Roots also sense most of physico-chemical parameters of the soil, perceive signals from the shoots, and adjust their growth and water transport properties accordingly. The present opinion paper discusses the significance of the variable water transport capacity (hydraulic conductance) of roots, during development and in responses to environmental stimuli. It is shown that root hydraulics determines water uptake intensities but also water potential gradients within the plant. It is indicated how the dynamics of root hydraulics contributes to many integrated plant nutritional and growth functions. For instance, the heterogeneity of soil water and nutrient availability and the heterogeneity of root hydraulic properties feed each other and play critical roles in root transport functions. Another important aspect is the integration of root hydraulics within the mutual interactions of roots and shoots, for coordinated growth and water saving responses to drought.