Abstract
Water availability is one of the most limiting factors for plant growth and crop productivity. Root water uptake capacity is governed by root system architecture (RSA) and root hydraulic conductivity (Lpr). These two parameters define the hydraulic architecture of the roots. Maize (Zea mays) develops a root system made up of embryonic roots (primary roots -PR- and seminal roots -SR-) and stem roots, all of which bear lateral roots (LR). We studied the responses of maize roots to water deficit (WD), focusing on three major aspects: hydraulics, growth and signalling. We targeted PRs, SRs and their LRs in young plants of a hybrid genotype (B73H) grown in hydroponics. To study RSA and Lpr responses in these different roots, a WD was imposed by adding polyethylene glycol (PEG-8000) to the hydroponic solution. A heterogeneous WD was created using a split-root system that allowed one half of the root system to be under well-hydrated conditions (WW) while the other half was under WD. Morphological and functional analyses showed specific responses from PR and SR. Under homogeneous WD, different behaviours were also observed depending on the stress intensity. After 1 h of moderate WDTranslated with DeepL.com (free version)