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

Cui, Hongchang

Hao, Yueling

Kovtun, Mikhail

Stolc, Viktor

Deng, Xing-Wang

Sakakibara, Hitoshi

Kojima, Mikiko

United States

2017-06-07T20:17:04Z

2017-06-07T20:17:04Z

2011-11

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.

https://www.ncbi.nlm.nih.gov/pubmed/21951467

pp.111.183178

1532-2548

https://hdl.handle.net/10161/14887

eng

American Society of Plant Biologists (ASPB)

Plant Physiol

10.1104/pp.111.183178

Arabidopsis

Arabidopsis Proteins

Body Patterning

Chromatin Immunoprecipitation

Cluster Analysis

Cytokinins

Gene Expression Regulation, Plant

Genome, Plant

Green Fluorescent Proteins

Homeostasis

Microscopy, Confocal

Mutation

Oligonucleotide Array Sequence Analysis

Phenotype

Phloem

Plant Vascular Bundle

Transcription Factors

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

Journal article

https://www.ncbi.nlm.nih.gov/pubmed/21951467

1221

1231

3

Center for Population Health & Aging

Duke

Duke Population Research Institute

Sanford School of Public Policy

Staff

Published

157