A PXY-Mediated Transcriptional Network Integrates Signaling Mechanisms to Control Vascular Development in Arabidopsis

Smit, M.; McGregor, S.; Sun, H.; Gough, C.; Bågman, A.-M.; Soyars, C.L.; Kroon, J.T.M.; Gaudinier, A.; Williams, C.J.; Yang, X.; Nimchuk, Z.L.; Weijers, D.; Turner, S.R.; Brady, S.M.; Etchells, J.P.

doi:10.1105/tpc.19.00562

A PXY-Mediated Transcriptional Network Integrates Signaling Mechanisms to Control Vascular Development in Arabidopsis

Smit, M.; McGregor, S.; Sun, H.; Gough, C.; Bågman, A.-M.; Soyars, C.L.; Kroon, J.T.M.; Gaudinier, A.; Williams, C.J.; Yang, X.; Nimchuk, Z.L.; Weijers, D.; Turner, S.R.; Brady, S.M.; Etchells, J.P.

Authors

M. Smit

S. McGregor

H. Sun

C. Gough

A.-M. Bågman

C.L. Soyars

Dr Johannes Kroon j.t.m.kroon@durham.ac.uk
Senior Experimental Officer

A. Gaudinier

C.J. Williams

X. Yang

Z.L. Nimchuk

D. Weijers

S.R. Turner

S.M. Brady

Dr Peter Etchells peter.etchells@durham.ac.uk
Associate Professor

Abstract

Vascular meristems generate the majority of biomass in higher plants. They constitute a bifacial stem cell population from which xylem and phloem are specified on opposing sides by positional signals. The PHLOEM INTERCALATED WITH XYLEM (PXY) receptor kinase promotes vascular cell division and organisation. However, how these functions are specified and integrated is unknown. Here, a putative PXY-mediated transcriptional regulatory network comprised of 690 transcription factor-promoter interactions was mapped. Among these interactions was a feed-forward loop containing transcription factors WUSCHEL HOMEOBOX RELATED 14 (WOX14) and TARGET OF MONOPTEROS 6 (TMO6), which each regulate the expression of a third transcription factor, LATERAL ORGAN BOUNDARIES DOMAIN 4 (LBD4). PXY signalling in turn regulates the WOX14, TMO6, LBD4 loop to control vascular proliferation. Genetic interaction between LBD4 and PXY suggests that LBD4 marks the phloem-procambium boundary, thus defining the shape of the vascular bundle. These data collectively support a novel mechanism that influences recruitment of cells into the phloem lineage, and defines the role of PXY signalling in this context to the arrangement of vascular tissue.

Citation

Smit, M., McGregor, S., Sun, H., Gough, C., Bågman, A., Soyars, C., …Etchells, J. (2020). A PXY-Mediated Transcriptional Network Integrates Signaling Mechanisms to Control Vascular Development in Arabidopsis. The Plant Cell, 32, 319-335. https://doi.org/10.1105/tpc.19.00562

Journal Article Type	Article
Acceptance Date	Dec 5, 2019
Online Publication Date	Dec 5, 2019
Publication Date	Feb 28, 2020
Deposit Date	Dec 10, 2019
Publicly Available Date	Dec 10, 2019
Journal	Plant Cell
Print ISSN	1040-4651
Electronic ISSN	1532-298X
Publisher	Oxford University Press
Peer Reviewed	Peer Reviewed
Volume	32
Pages	319-335
DOI	https://doi.org/10.1105/tpc.19.00562