title: Multiple phytohormones promote root hair elongation by regulating a similar set of genes in the root epidermis in Arabidopsis.
abstract: Multiple phytohormones, including auxin, ethylene, and cytokinin, play vital roles in regulating cell development in the root epidermis. However, their interactions in specific root hair cell developmental stages are largely unexplored. To bridge this gap, we employed genetic and pharmacological approaches as well as transcriptional analysis in order to dissect their distinct and overlapping roles in root hair initiation and elongation in Arabidopsis thaliana Our results show that among auxin, ethylene, and cytokinin, only ethylene induces ectopic root hair cells in wild-type plants, implying a special role of ethylene in the hair initiation stage. In the subsequent elongation stage, however, auxin, ethylene, and cytokinin enhance root hair tip growth equally. Our data also suggest that the effect of cytokinin is independent from auxin and ethylene in this process. Exogenous cytokinin restores root hair elongation when the auxin and ethylene signal is defective, whereas auxin and ethylene also sustain elongation in the absence of the cytokinin signal. Notably, transcriptional analyses demonstrated that auxin, ethylene, and cytokinin regulate a similar set of root hair-specific genes. Together these analyses provide important clues regarding the mechanism of hormonal interactions and regulation in the formation of single-cell structures.
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Shan
authors: S
authors: Zhang
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Linli
authors: L
authors: Huang
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: An
authors: A
authors: Yan
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Yihua
authors: Y
authors: Liu
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Bohan
authors: B
authors: Liu
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Chunyan
authors: C
authors: Yu
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
authors: Aidong
authors: A
authors: Zhang
authors: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
authors: John
authors: J
authors: Schiefelbein
authors: Zhejiang Key Laboratory of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China ygan@zju.edu.cn.
authors: Yinbo
authors: Y
authors: Gan
mesh_terms: D017360:Arabidopsis / Q000254:growth & development* / Q000502:physiology; D049108:Cell Enlargement; D003583:Cytokinins / Q000378:metabolism / Q000502:physiology; D005030:Ethylenes / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism; D010937:Plant Growth Regulators / Q000502:physiology*; D018517:Plant Roots / Q000254:growth & development* / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology
chemical_list: D003583:Cytokinins; D005030:Ethylenes; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C036216:ethylene
keywords: 
  Arabidopsis thaliana
  ; auxin; cytokinin; ethylene; phytohormones; root hair; tip growth.