PIN-FORMED1 polarity in the shoot is insensitive to the polarity of neighbouring cells

Abstract

Cell polarity patterns associated with plant phyllotaxis are thought to be determined by mechanical signals or auxin flux. Here we use mosaic expression of the serine threonine kinase PINOID (PID) in the shoot to investigate the flux hypothesis. We find that PID promotes changes in PIN1 polarity irrespective of initial or neighboring cell polarities, arguing against a role for flux in regulating phyllotaxis.

Integration of Core Mechanisms Underlying Plant Aerial Architecture

“…Alternatively, auxin acting through MP may promote auxin influx and degradation, thereby increasing auxin flux from neighboring cells, which might act as the polarity cue ( Abley et al, 2016 ; Figure 3D ). However, a recent study indicates that PIN1 polarity is relative insensitive to the polarity of neighboring cells arguing against auxin flux as a polarity determinant ( Kareem et al, 2021 ).…”