Genome-wide direct target analysis reveals a role for SHORT-ROOT in root vascular patterning through cytokinin homeostasis.

Loading...
Thumbnail Image

Date

2011-11

Journal Title

Journal ISSN

Volume Title

Repository Usage Stats

119
views
162
downloads

Citation Stats

Attention Stats

Abstract

SHORT-ROOT (SHR) is a key regulator of root growth and development in Arabidopsis (Arabidopsis thaliana). Made in the stele, the SHR protein moves into an adjacent cell layer, where it specifies endodermal cell fate; it is also essential for apical meristem maintenance, ground tissue patterning, vascular differentiation, and lateral root formation. Much has been learned about the mechanism by which SHR controls radial patterning, but how it regulates other aspects of root morphogenesis is still unclear. To dissect the SHR developmental pathway, we have determined the genome-wide locations of SHR direct targets using a chromatin immunoprecipitation followed by microarray analysis method. K-means clustering analysis not only identified additional quiescent center-specific SHR targets but also revealed a direct role for SHR in gene regulation in the pericycle and xylem. Using cell type-specific markers, we showed that in shr, the phloem and the phloem-associated pericycle expanded, whereas the xylem and xylem-associated pericycle diminished. Interestingly, we found that cytokinin level was elevated in shr and that exogenous cytokinin conferred a shr-like vascular patterning phenotype in wild-type root. By chromatin immunoprecipitation-polymerase chain reaction and reverse transcription-polymerase chain reaction assays, we showed that SHR regulates cytokinin homeostasis by directly controlling the transcription of cytokinin oxidase 3, a cytokinin catabolism enzyme preferentially expressed in the stele. Finally, overexpression of a cytokinin oxidase in shr alleviated its vascular patterning defect. On the basis of these results, we suggest that one mechanism by which SHR controls vascular patterning is the regulation of cytokinin homeostasis.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1104/pp.111.183178

Publication Info

Cui, Hongchang, Yueling Hao, Mikhail Kovtun, Viktor Stolc, Xing-Wang Deng, Hitoshi Sakakibara and Mikiko Kojima (2011). Genome-wide direct target analysis reveals a role for SHORT-ROOT in root vascular patterning through cytokinin homeostasis. Plant Physiol, 157(3). pp. 1221–1231. 10.1104/pp.111.183178 Retrieved from https://hdl.handle.net/10161/14887.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Kovtun

Mikhail Kovtun

Biostatistician III

Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.