Abscisic acid and nitric oxide modulate cytoskeleton organization, root hair growth and ectopic hair formation in Arabidopsis

Publication date: Available online 17 September 2018Source: Nitric OxideAuthor(s): María Cristina Lombardo, Lorenzo LamattinaAbstractAbscisic acid (ABA) and nitric oxide (NO) are two plant growth regulators that participate in many signaling cascades in different organs all along the plant life. Here, we were interested in deciphering the effects of ABA and NO on the cytoskeleton organization in a model of polarized cell growth like root hairs. Arabidopsis roots were exposed to different concentrations of ABA, and the length of primary root, epidermal cells and root hairs were measured. The NO concentration was detected with the NO-specific fluorescent probe DAF-FM DA. To quantify the effects of ABA and NO on cytoskeleton, Arabidopsis seedlings expressing GFP-MAP4 were used to analyze microtubules (MTs) orientation. Changes in cytoplasmic streaming were quantified through fluorescence recovery after photobleaching (FRAP) experiments using confocal laser canning microscopy (CLSM) and the probe fluorescein diacetate (FDA). Results indicate that ABA decreases root hair length and induces the differentiation of atrichoblasts into trichoblasts, increasing root hair density. ABA also triggers an increase of NO level in root hairs. Both, ABA and NO affect MT organization in root hairs. While root hairs show MT orientation close to the longitudinal axis in control roots, ABA and NO treatments induce the oblique orientation of MTs. In parallel, cytoplasmic flow, executed by actin cyt...
Source: Nitric Oxide - Category: Chemistry Source Type: research