Analyzing the complexity of auxin-related processes and their regulation

Abstract

Phytohormone auxin plays an important role in various aspects of plant growth and development. The necessary concentration maxima at the region of its action are achieved by auxin metabolism, passive diffusion of auxin molecules across plasma membrane and by the carrier-mediated auxin transport, as well as by modulation of these processes. In our study we used a group of compounds structurally related to major endogenous auxin indole-3-acetic acid, as well as synthetic auxins 2,4-dichlorophenoxy acetic acid (2,4- D) and naphthalene-1-acetic acid (NAA). We aimed to characterize the auxin specificity of developmentally important processes such as carrier-mediated auxin transport, and 'genomic' (transcriptional) and 'non-genomic' (transcriptional) auxin signaling. In addition to the characterization of these compounds we also hoped to get an insight into the complex regulatory mechanism of auxin-related processes and to possibly find a particular compound with distinct behavior towards particular processes. By making use of such compounds and other molecular tools we aimed to analyze the mechanism of 'non-genomic' auxin signaling, to understand the mode of action of FM (Fei Mao) styryl dyes on the dynamics of membrane- localized auxin transporters, and to study the involvement of other phytohormones..