共 69 条
TCP1 Modulates Brassinosteroid Biosynthesis by Regulating the Expression of the Key Biosynthetic Gene DWARF4 in Arabidopsis thaliana
被引:170
作者:
Guo, Zhongxin
[1
]
Fujioka, Shozo
[2
]
Blancaflor, Elison B.
[3
]
Miao, Sen
[1
]
Gou, Xiaoping
[1
,4
]
Li, Jia
[1
,4
]
机构:
[1] Univ Oklahoma, Dept Bot & Microbiol, Norman, OK 73019 USA
[2] RIKEN, Adv Sci Inst, Wako, Saitama 3510198, Japan
[3] Samuel Roberts Noble Fdn Inc, Div Plant Biol, Ardmore, OK 73401 USA
[4] Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Peoples R China
来源:
基金:
美国国家科学基金会;
中国国家自然科学基金;
关键词:
RECEPTOR INTERACTING PROTEIN;
SIGNAL-TRANSDUCTION;
PLANT-GROWTH;
TRANSCRIPTION FACTORS;
PLASMA-MEMBRANE;
C-6;
OXIDATION;
KINASE;
BRI1;
CYTOCHROME-P450;
HOMEOSTASIS;
D O I:
10.1105/tpc.109.069203
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
Brassinosteroids (BRs) are essential phytohormones regulating normal plant growth and development. TCP1, a gene thought to be involved in floral organ symmetric control, was identified as a genetic suppressor of a weak BR receptor mutant, bri1-5, in an activation-tagging genetic screen. TCP1 encodes a putative transcription factor possessing a basic helix-loop-helix domain. The dominant allele of TCP1, tcp1-1D, suppresses the defective phenotypes of bri1-5. Overexpression of a dominant-negative form of TCP1, TCP1-SRDX, with a 12-amino acid repressor sequence fused to TCP1 at its C terminus, results in dwarfed plants resembling BR-deficient or insensitive mutants. The defective phenotypes can be rescued by exogenously applied brassinolide but cannot be recovered by auxins, gibberellins, or cytokinins. BR profile assay (quantitative analysis of BR biosynthetic intermediates) strongly suggests that TCP1 expression level positively coordinates with the function of DWARF4 (DWF4), a key enzyme in BR biosynthesis. Real-time RT-PCR analysis further demonstrated that TCP1 regulates the transcription levels of DWF4, and chromatin immunoprecipitation experiments showed that TCP1 indeed interacts with the DWF4 promoter. Confocal microscopy indicated that TCP1 is mainly confined to the nucleus. The expression of TCP1 appears to be regulated by BR levels. These studies demonstrate another level of regulation through which BRs mediate plant growth and development.
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页码:1161 / 1173
页数:13
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