For plants and especially for maize (Zea mays), experiencing water deficit at key phenological stages can cause critical yield losses. As such, there is a need to understand the complex plant hydraulic behavior in constraining environments. Within plant diversity, landraces may hold root systems hydraulic architecture that are well fitted to specific pedo-climatic environments. Their sets of traits could be "key" candidates to promote sustainable farming practices and alleviate the consequences of drought episodes. However, due to the difficulties of quantifying the root hydraulic anatomy, there is a knowledge gap in the identification of suitable combinations of root traits. Therefore, developing new ways to explore and evaluate the influence of root hydraulic anatomy on water uptake will be beneficial.

In this thesis, we advance our understanding on hydraulic anatomy influence at different scales and for specific soil and environmental constraints.

Firstly, we created a new way to estimate root hydraulic properties. Secondly, we developed a method to generate root hydraulic atlases based on a combination of root cross-section images and modeling tools. Then, we investigated in silico the crucial role of root anatomy, subcellular hydraulic properties and maturation stages on water uptake. It showed that the root radii, the contribution of aquaporins to the cell membrane permeability and root maturation rates can create contrasted uptake patterns and influence the cumulative water

uptake of in silico maize plants. These exploratory findings inform potential candidate sets of traits which could be investigated furthermore.