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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-5-28
pubmed:abstractText
Auxin and brassinosteroid (BR) play essential roles in diverse aspects of growth and developmental processes in plants mainly through coordinate regulation of cell division, elongation, and differentiation. Consistent with the overlapped roles, accumulating evidence indicates that the two growth hormones act in a synergistic as well as in an interdependent manner in many cases, although the underlying molecular mechanisms are not fully understood. Here, we demonstrate that auxin and BR signaling pathways are interconnected at the transcriptional level via a negative feedback loop. An Arabidopsis activating tagging mutant dlf-1D exhibited dwarfed growth with small, dark-green leaves and reduced fertility. Hormone feeding assays revealed that the mutant phenotype is caused by the reduction of endogenous BR level. Consistent with this, a gene encoding the CYP72C1 enzyme that catabolizes BR was up-regulated. Notably, the transcript level of the ARF8 transcription factor gene, which modulates the expression of auxin-responsive genes, was significantly elevated in the mutant. In addition, the ARF8 gene expression was significantly reduced by BR but induced by brassinazole, a BR biosynthetic inhibitor. On the other hand, two BR catabolic pathway genes, DLF (CYP72C1) and BAS1, were induced by auxin. Our observations indicate that at least part of auxin and BR signaling pathways are unified through a transcriptional feedback control of the DLF and ARF8 genes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0219-1032
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
449-56
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
A transcriptional feedback loop modulating signaling crosstalks between auxin and brassinosteroid in Arabidopsis.
pubmed:affiliation
Department of Chemistry, Seoul National University, Seoul, 151-742, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't