title: Promotive effect of brassinosteroids on cell division involves a distinct CycD3-induction pathway in Arabidopsis.
abstract: Brassinosteroids (BRs) are steroid hormones that play an essential role in plant growth and development. However, the contradictory results of previous studies make their role in cell division unclear. Using a cDNA array, we identified genes that respond to BR in the det2 suspension culture of Arabidopsis, and found that epi-brassinolide upregulated transcription of the CycD3, a D-type plant cyclin gene through which cytokinin activates cell division. RNA gel-blot analysis and cell culturing showed that epi-brassinolide may promote cell division through CycD3, and can substitute cytokinin in culturing of Arabidopsis callus and suspension cells. The CycD3 induction by epi-brassinolide was further shown to involve de novo protein synthesis, but no protein phosphorylation or dephosphorylation. Induction was also found to occur in cells of a BR-insensitive mutant, bri1, suggesting that BR induces CycD3 transcription through a previously unknown signal pathway in plants.
authors: Institute of Genetics, Chinese Academy of Sciences, Beijing 100101, China.
authors: Y
authors: Y
authors: Hu
authors: F
authors: F
authors: Bao
authors: J
authors: J
authors: Li
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D060406:Brassinosteroids; D002455:Cell Division / Q000187:drug effects*; D002777:Cholestanols / Q000494:pharmacology*; D016213:Cyclins / Q000235:genetics* / Q000502:physiology; D003583:Cytokinins / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018749:RNA, Plant / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013260:Steroids, Heterocyclic / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D015026:Zeatin / Q000494:pharmacology
chemical_list: D060406:Brassinosteroids; D002777:Cholestanols; D016213:Cyclins; D003583:Cytokinins; D018076:DNA, Complementary; D010937:Plant Growth Regulators; D018749:RNA, Plant; D013260:Steroids, Heterocyclic; D015026:Zeatin; C023623:brassinolide