Spatiotemporal brassinosteroid signaling and antagonism with auxin pattern stem cell dynamics in Arabidopsis roots
| Autor: | Zhi-Yong Wang, Juthamas Chaiwanon |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
0106 biological sciences
Arabidopsis Plant Development 01 natural sciences Plant Roots General Biochemistry Genetics and Molecular Biology Article Transcriptome 03 medical and health sciences chemistry.chemical_compound Auxin Gene Expression Regulation Plant Gene expression Botany Brassinosteroids Brassinosteroid Transcription factor 030304 developmental biology Regulation of gene expression chemistry.chemical_classification 0303 health sciences biology Indoleacetic Acids Arabidopsis Proteins Stem Cells food and beverages Nuclear Proteins biology.organism_classification Cell biology DNA-Binding Proteins chemistry Stem cell General Agricultural and Biological Sciences 010606 plant biology & botany Signal Transduction |
| Zdroj: | Current biology : CB. 25(8) |
| ISSN: | 1879-0445 |
| Popis: | SummaryThe spatiotemporal balance between stem cell maintenance, proliferation, and differentiation determines the rate of root growth and is controlled by hormones, including auxin and brassinosteroid (BR). However, the spatial actions of BR and its interactions with auxin remain unclear in roots. Here, we show that oppositely patterned and antagonistic actions of BR and auxin maintain the stem cell balance and optimal root growth. We discover a pattern of low levels of nuclear-localized BR-activated transcription factor BZR1 in the stem cell niche and high BZR1 levels in the transition-elongation zone. This BZR1 pattern requires local BR catabolism and auxin synthesis, as well as BR signaling. Cell-type-specific expression of a constitutively active form of BZR1 confirms that the high and low levels of BZR1 are required for the normal cell behaviors in the elongation zone and quiescent center (QC), respectively. Comparison between BR-responsive, BZR1-targeted, auxin-responsive, and developmental zone-specific transcriptomes indicates that BZR1 mostly activates its target genes expressed in the transition-elongation zone, but represses genes in the QC and surrounding stem cells, and that BR and auxin have overall opposite effects on gene expression. Genetic and physiological interactions support that a balance between the antagonistic actions of BR and auxin is required for optimal root growth. These results demonstrate that the level and output specificity of BR signaling are spatially patterned and that, in contrast to their synergism in shoots, BR and auxin interact antagonistically in roots to control the spatiotemporal balance of stem cell dynamics required for optimal root growth. |
| Databáze: | OpenAIRE |
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