Hormonal control of the shoot stem-cell niche

• Published in: Nature (London) 2010-06, Vol.465 (7301), p.1089-1092
• Main Authors: Lohmann, Jan U, Zhao, Zhong, Andersen, Stig U, Ljung, Karin, Dolezal, Karel, Miotk, Andrej, Schultheiss, Sebastian J
• Format: Article
• Language: English
• Subjects: 631/136/532/2139; 631/449/1741; 631/449/2491; Arabidopsis - cytology; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Biosynthesis; Cell cycle; Cluster analysis; Competition; Cytokinins - metabolism; Cytokinins - pharmacology; DNA-Binding Proteins - deficiency; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Ethanol; Forest Science; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Growth regulators; Hormones; Humanities and Social Sciences; Indoleacetic Acids - metabolism; Indoleacetic Acids - pharmacology; letter; Meristem - cytology; Meristem - drug effects; Meristem - genetics; Meristem - metabolism; Metabolism; multidisciplinary; Plant Growth Regulators - metabolism; Plant Growth Regulators - pharmacology; Plant physiology and development; Plant Roots; Plant Shoots - cytology; Plant Shoots - drug effects; Plant Shoots - metabolism; Principal components analysis; Proteins; Scanning electron microscopy; Science; Science (multidisciplinary); Signal transduction; Signal Transduction - drug effects; Skogsvetenskap; Stem Cell Niche - cytology; Stem Cell Niche - drug effects; Stem Cell Niche - metabolism; Stem Cells - cytology; Stem Cells - drug effects; Transcription Factors - deficiency; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/nature09126

The classic phytohormones cytokinin and auxin play essential roles in the maintenance of stem-cell systems embedded in shoot and root meristems, and exhibit complex functional interactions. Here we show that the activity of both hormones directly converges on the promoters of two A-type ARABIDOPSIS RESPONSE REGULATOR (ARR) genes, ARR7 and ARR15, which are negative regulators of cytokinin signalling and have important meristematic functions. Whereas ARR7 and ARR15 expression in the shoot apical meristem (SAM) is induced by cytokinin, auxin has a negative effect, which is, at least in part, mediated by the AUXIN RESPONSE FACTOR5/MONOPTEROS (MP) transcription factor. Our results provide a mechanistic framework for hormonal control of the apical stem-cell niche and demonstrate how root and shoot stem-cell systems differ in their response to phytohormones.