Arabidopsis AIP1-2 restricted by WER-mediated patterning modulates planar polarity

Abstract

The coordination of cell polarity within the plane of the tissue layer (planar polarity) is crucial for the development of diverse multicellular organisms.Small Rac/Rho-familyGTPases and the actin cytoskeleton contribute to planar polarity formation at sites of polarity establishment in animals and plants. Yet, upstream pathways coordinating planar polarity differ strikingly between kingdoms. In the root of Arabidopsis thaliana, a concentration gradient of the phytohormone auxin coordinates polar recruitment of Rho-of-plant (ROP) to sites of polar epidermal hair initiation. However, little is known about cytoskeletal components and interactions that contribute to this planar polarity or about their relation to the patterning machinery. Here, we show that ACTIN7 (ACT7) represents a main actin isoform required for planar polarity of root hair positioning, interacting with the negative modulator ACTIN-INTERACTINGPROTEIN1-2 (AIP1-2). ACT7, AIP1-2 and their genetic interaction are required for coordinated planar polarity of ROP downstream of ethylene signalling. Strikingly, AIP1-2 displays hair cell file-enriched expression, restricted by WEREWOLF (WER)-dependent patterning and modified by ethylene and auxin action. Hence, our findings reveal AIP1-2, expressed under control of the WER-dependent patterning machinery and the ethylene signalling pathway, as a modulator of actin-mediated planar polarity.

Keywords

Actin; AIP1; Arabidopsis; Patterning; Planar polarity; WEREWOLF

Published in

Development
2015, volume: 142, number: 1, pages: 151-161
Publisher: Company of Biologists Ltd

SLU Authors

• Claes, Andrea

  • Umeå University

UKÄ Subject classification

Developmental Biology

Publication identifier

• DOI: https://doi.org/10.1242/dev.111013

Permanent link to this page (URI)

https://res.slu.se/id/publ/132084