Drought resistance in oat involves ABA-mediated modulation of transpiration and root hydraulic conductivity

Drought is one of the most important constraints to crop productivity worldwide. Control plant responses drought very complex. The mechanisms and their intensity may differ between species and/or genotypes ultimately conditioning tolerance or susceptibility. We explore here strategy set up by two oat cultivars cope with based on root morphological, anatomical, physiological molecular studies. A dramatic rapid abscisic acid increase in susceptible genotype resulted a tight reduction stomatal conductance. Despite this, leaf water potential decreased concomitantly due decrease hydraulic conductivity. By contrast, resistant genotype, showed mild slow that allowed maintaining transpiration longer. This response was linked an conductance through total length thinnest roots as well rise also coupled anatomical changes leading metabolic cost. These maintain higher reducing symptoms promoting growth under deficit conditions.