Indole‐3‐butyric acid induces lateral root formation via peroxisome‐derived indole‐3‐acetic acid and nitric oxide

Abstract

SummaryControlled plant growth requires regulation through a variety of signaling molecules, including steroids, peptides, radicals of oxygen and nitrogen, as well as the 'classical' phytohormone groups. Auxin is critical for the control of plant growth and also orchestrates many developmental processes, such as the formation of new roots. It modulates root architecture both slowly, through actions at the transcriptional level and, more rapidly, by mechanisms targeting primarily plasma membrane sensory systems and intracellular signaling pathways. The latter reactions use several second messengers, including Ca 2+ , nitric oxide (NO) and reactive oxygen species (ROS). Here, we investigated the different roles of two auxins, the major auxin indole-3-acetic acid (IAA) and another endogenous auxin indole-3-butyric acid (IBA), in the lateral root formation process of Arabidopsis and maize. This was mainly analyzed by different types of fluorescence microscopy and inhibitors of NO production.This study revealed that peroxisomal IBA to IAA conversion is followed by peroxisomal NO, which is important for IBA-induced lateral root formation.We conclude that peroxisomal NO emerges as a new player in auxin-induced root organogenesis. In particular, the spatially and temporally coordinated release of NO and IAA from peroxisomes is behind the strong promotion of lateral root formation via IBA.

Nitric oxide mediates strigolactone signaling in auxin and ethylene-sensitive lateral root formation in sunflower seedlings

“…64 NO is emerging as a player in LR development due to its signling role in conversion of local peroxisomal IBA to IAA, which is important for LR formation. [64][65][66] In the present work, attempts have been made to examine the critical role of SLs in LR formation in seedling roots and AR development from the basal region of hypocotyls cut ends in context with a crosstalk of SL action with auxin and ethylene. Analysis of ACC synthase activity and PIN1 protein distribution in seedling roots and their regulation by SL and associated biomolecules (Fl, SL biosynthesis inhibitor; NPA, PIN blocker) has also been undertaken.…”

A Critical View on ABC Transporters and Their Interacting Partners in Auxin Transport

“…Currently it is unclear if IBA acts as an auxin by itself or if it is a precursor of IAA and thus acts via IAA (Ludwig-Muller 2007, Schlicht et al 2013. Moreover, the existence of IBA in the model plant Arabidopsis has been questioned (Novak et al 2012), although this might simply be a question of extraction and detection methods.…”

Maintenance of quality of Dalbergia nigra Vell. all. ex. Benth seeds during storage by sodium nitroprusside

“…The nitric oxide (NO) is a colorless, inorganic freeradical, synthesized in plants fromenzy matic pathways, that include nitrate reductase or nitric oxide synthase or by nonenzymatic pathways, by production of NO from nitrification/ denitrification processes (Scheler et al, 2013;Sidana et al, 2015). Its participation is evidenced in countless plant physiological processes, among which is the protective function against oxidative stress (Besson-Bard et al, 2008).…”

“…In seeds, NO stimulates germination both under normal and stress conditions (Zhang et al, 2011;He et al, 2014;Pires et al, 2016), favors overcoming dormancy (Wang et al, 2015;Ma et al, 2016), promotes elongation and formation of adventitious roots (Schlicht et al, 2013;Bai et al, 2014) and enhances desiccation tolerance of recalcitrant seeds (Bai et al, 2011).…”