Repository logo
 

Connective Auxin Transport in the Shoot Facilitates Communication between Shoot Apices.


Change log

Authors

Bennett, Tom 
Hines, Geneviève 
van Rongen, Martin 
Sawchuk, Megan G 

Abstract

The bulk polar movement of the plant signaling molecule auxin through the stem is a long-recognized but poorly understood phenomenon. Here we show that the highly polar, high conductance polar auxin transport stream (PATS) is only part of a multimodal auxin transport network in the stem. The dynamics of auxin movement through stems are inconsistent with a single polar transport regime and instead suggest widespread low conductance, less polar auxin transport in the stem, which we term connective auxin transport (CAT). The bidirectional movement of auxin between the PATS and the surrounding tissues, mediated by CAT, can explain the complex auxin transport kinetics we observe. We show that the auxin efflux carriers PIN3, PIN4, and PIN7 are major contributors to this auxin transport connectivity and that their activity is important for communication between shoot apices in the regulation of shoot branching. We propose that the PATS provides a long-range, consolidated stream of information throughout the plant, while CAT acts locally, allowing tissues to modulate and be modulated by information in the PATS.

Description

Keywords

Biological Transport, Indoleacetic Acids, Kinetics, Plant Proteins, Plant Shoots, Plant Stems

Journal Title

PLoS Biol

Conference Name

Journal ISSN

1544-9173
1545-7885

Volume Title

14

Publisher

Public Library of Science (PLoS)
Sponsorship
European Research Council (294514)