Score: 10.00 |
|---|
| Title: Antagonistic HLH/bHLH Transcription Factors Mediate Brassinosteroid Regulation of Cell Elongation and Plant Development in Rice and Arabidopsis .
| | Author: Zhang LY Bai MY Wu J Zhu JY Wang H Zhang Z Wang W Sun Y Zhao J Sun X Yang H Xu Y Kim SH Fujioka S Lin WH Chong K Lu T Wang ZY | | Journal: Plant Cell Citation: V : P : Year: 2009 Type: Publisher | | Literature: oryza Field: abstract Doc ID: pub20009022 Accession (PMID): 20009022 | | Abstract: In rice ( Oryza sativa ) , brassinosteroids ( BRs ) induce cell elongation at the adaxial side of the lamina joint to promote leaf bending .
We identified a rice mutant ( ili1-D ) showing an increased lamina inclination phenotype similar to that caused by BR treatment .
The ili1-D mutant overexpresses an HLH protein homologous to Arabidopsis thaliana Paclobutrazol Resistance1 ( PRE1 ) and the human Inhibitor of DNA binding proteins .
Overexpression and RNA interference suppression of ILI1 increase and reduce , respectively , rice laminar inclination , confirming a positive role of ILI1 in leaf bending .
ILI1 and PRE1 interact with basic helix-loop-helix ( bHLH ) protein IBH1 ( ILI1 binding bHLH ) , whose overexpression causes erect leaf in rice and dwarfism in Arabidopsis .
Overexpression of ILI1 or PRE1 increases cell elongation and suppresses dwarf phenotypes caused by overexpression of IBH1 in Arabidopsis .
Thus , ILI1 and PRE1 may inactivate inhibitory bHLH transcription factors through heterodimerization .
BR increases the RNA levels of ILI1 and PRE1 but represses IBH1 through the transcription factor BZR1 .
The spatial and temporal expression patterns support roles of ILI1 in laminar joint bending and PRE1/At IBH1 in the transition from growth of young organs to growth arrest These results demonstrate a conserved mechanism of BR regulation of plant development through a pair of antagonizing HLH/bHLH transcription factors that act downstream of BZR1 in Arabidopsis and rice .
| Matching Sentences:
[ Sen. 4, subscore: 2.00 ]: Overexpression and RNA interference suppression of ILI1 increase and reduce , respectively , rice laminar inclination , confirming a positive role of ILI1 in leaf bending .
[ Sen. 5, subscore: 2.00 ]: ILI1 and PRE1 interact with basic helix-loop-helix ( bHLH ) protein IBH1 ( ILI1 binding bHLH ) , whose overexpression causes erect leaf in rice and dwarfism in Arabidopsis .
[ Sen. 2, subscore: 1.00 ]: We identified a rice mutant ( ili1-D ) showing an increased lamina inclination phenotype similar to that caused by BR treatment .
[ Sen. 3, subscore: 1.00 ]: The ili1-D mutant overexpresses an HLH protein homologous to Arabidopsis thaliana Paclobutrazol Resistance1 ( PRE1 ) and the human Inhibitor of DNA binding proteins .
[ Sen. 6, subscore: 1.00 ]: Overexpression of ILI1 or PRE1 increases cell elongation and suppresses dwarf phenotypes caused by overexpression of IBH1 in Arabidopsis .
[ Sen. 7, subscore: 1.00 ]: Thus , ILI1 and PRE1 may inactivate inhibitory bHLH transcription factors through heterodimerization .
[ Sen. 8, subscore: 1.00 ]: BR increases the RNA levels of ILI1 and PRE1 but represses IBH1 through the transcription factor BZR1 .
[ Sen. 9, subscore: 1.00 ]: The spatial and temporal expression patterns support roles of ILI1 in laminar joint bending and PRE1/At IBH1 in the transition from growth of young organs to growth arrest These results demonstrate a conserved mechanism of BR regulation of plant development through a pair of antagonizing HLH/bHLH transcription factors that act downstream of BZR1 in Arabidopsis and rice .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 2.00 |
|---|
| Title: Dynamics of brassinosteroid response modulated by negative regulator LIC in rice .
| | Author: Zhang C Xu Y Guo S Zhu J Huan Q Liu H Wang L Luo G Wang X Chong K | | Journal: PLoS Genet Citation: V : 8 P : e1002686 Year: 2012 Type: In-Process | | Literature: oryza Field: abstract Doc ID: pub22570626 Accession (PMID): 22570626 | | Abstract: Brassinosteroids ( BRs ) regulate rice plant architecture , including leaf bending , which affects grain yield .
Although BR signaling has been investigated in Arabidopsis thaliana , the components negatively regulating this pathway are less well understood .
Here , we demonstrate that Oryza sativa LEAF and TILLER ANGLE INCREASED CONTROLLER ( LIC ) acts as an antagonistic transcription factor of BRASSINAZOLE-RESISTANT 1 ( BZR1 ) to attenuate the BR signaling pathway .
The gain-of-function mutant lic-1 and LIC-overexpressing lines showed erect leaves , similar to BZR1-depleted lines , which indicates the opposite roles of LIC and BZR1 in regulating leaf bending .
Quantitative PCR revealed LIC transcription rapidly induced by BR treatment .
Image analysis and immunoblotting showed that upon BR treatment LIC proteins translocate from the cytoplasm to the nucleus in a phosphorylation-dependent fashion .
Phosphorylation assay in vitro revealed LIC phosphorylated by GSK3-like kinases .
For negative feedback , LIC bound to the core element CTCGC in the BZR1 promoter on gel-shift and chromatin immunoprecipitation assay and repressed its transcription on transient transformation assay .
LIC directly regulated target genes such as INCREASED LEAF INCLINATION 1 ( ILI1 ) to oppose the action of BZR1 .
Repression of LIC in ILI1 transcription in protoplasts was partially rescued by BZR1 .
Phenotypic analysis of the crossed lines depleted in both LIC and BZR1 suggested that BZR1 functionally depends on LIC .
Molecular and physiology assays revealed that LIC plays a dominant role at high BR levels , whereas BZR1 is dominant at low levels .
Thus , LIC regulates rice leaf bending as an antagonistic transcription factor of BZR1 .
The phenotypes of lic-1 and LIC-overexpressing lines in erect leaves contribute to ideal plant architecture .
Improving this phenotype may be a potential approach to molecular breeding for high yield in rice .
| Matching Sentences:
[ Sen. 9, subscore: 1.00 ]: LIC directly regulated target genes such as INCREASED LEAF INCLINATION 1 ( ILI1 ) to oppose the action of BZR1 .
[ Sen. 10, subscore: 1.00 ]: Repression of LIC in ILI1 transcription in protoplasts was partially rescued by BZR1 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
