Model-Assisted Integration of Genetic and Environmental Constraints for the Improvement of Crop Water Capture.

Increasing attention is being devoted to root system architecture in drought tolerance studies and breeding. Surprisingly, while the explicit consideration of architecture is a key to system-wide approaches of water dynamics in the soil-plant continuum, the influence of root architecture on soil moisture and nutrient distributions at the macroscopic to the plant scales is generally underemphasized in plant biology. In addition, although the impact of one-dimensional root distributions on the profile of depletion of soil water content has been shown in numerous studies, horizontal water content variability may arise due to contrasting uptake by different root segments and redistribution processes, even with uniform horizontal soil hydraulic properties. In this presentation, we highlight the importance of addressing the dynamics of the soil matrix in plant biology, to understand how water fluxes driven by soil and plant processes affect water availability and uptake throughout a growth cycle. We will present two- and three-dimensional models that involve a higher level of complexity in the description of root structure and related soil and plant processes. We will also present recent development in phenotyping root water uptake. We anticipate that coupling water dynamics models with QTL-based structure-function plant models will support model-assisted design of plant architectures susceptible to improve yield under given drought scenarios.