Root ABA Accumulation Delays Lateral Root Emergence in Osmotically Stressed Barley Plants by Decreasing Root Primordial IAA Accumulation

Increased auxin levels in root primordia are important controlling branching, while their interaction with abscisic acid (ABA) likely regulates lateral development water-deficient plants. The role of ABA accumulation regulating branching was investigated using immunolocalization to detect (indoleacetic acid, IAA) and (abscisic acid) the ABA-deficient barley mutant Az34 its parental genotype (cv. Steptoe) Osmotic stress strongly inhibited Steptoe plants, but hardly affected Az34. Root primordial cells plants had increased immunostaining for diminished staining IAA. did not accumulate Az34, IAA distribution were unaltered. Treating exogenous decreased concentration, increasing decreasing concentration. Although treatment number, it number visible emerged roots. These effects qualitatively similar that osmotic on roots Steptoe. Thus (and crosstalk auxin) seems response water stress.