BZR1 Is a Transcriptional Repressor with Dual Roles in Brassinosteroid Homeostasis and Growth Responses

Brassinosteroid (BR) homeostasis and signaling are crucial for normal growth and development of plants. BR signaling through cell-surface receptor kinases and intracellular components leads to dephosphorylation and accumulation of the nuclear protein BZR1. How BR signaling regulates gene expression, however, remains unknown. Here we show that BZR1 is a transcriptional repressor that has a previously unknown DNA binding domain and binds directly to the promoters of feedback-regulated BR biosynthetic genes. Microarray analyses identified additional potential targets of BZR1 and illustrated, together with physiological studies, that BZR1 coordinates BR homeostasis and signaling by playing dual roles in regulating BR biosynthesis and downstream growth responses.

[1]  J. Botto,et al.  The plant cell , 2007, Plant Molecular Biology Reporter.

[2]  宁北芳,et al.  疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A , 2005 .

[3]  J. B. Reid,et al.  Brassinosteroids Do Not Undergo Long-Distance Transport in Pea. Implications for the Regulation of Endogenous Brassinosteroid Levels1 , 2004, Plant Physiology.

[4]  M. Estelle,et al.  Auxin signaling and regulated protein degradation. , 2004, Trends in plant science.

[5]  Yukihisa Shimada,et al.  Comprehensive Comparison of Auxin-Regulated and Brassinosteroid-Regulated Genes in Arabidopsis[w] , 2004, Plant Physiology.

[6]  Ana I. Caño-Delgado,et al.  Nuclear protein phosphatases with Kelch-repeat domains modulate the response to brassinosteroids in Arabidopsis. , 2004, Genes & development.

[7]  Zhi-Yong Wang,et al.  Brassinosteroid signal transduction--choices of signals and receptors. , 2004, Trends in plant science.

[8]  S. Tiwari,et al.  Aux/IAA Proteins Contain a Potent Transcriptional Repression Domain , 2004, The Plant Cell Online.

[9]  Jianming Li.  Brassinosteroids signal through two receptor-like kinases. , 2003, Current opinion in plant biology.

[10]  S. Fujioka,et al.  Organ-Specific Expression of Brassinosteroid-Biosynthetic Genes and Distribution of Endogenous Brassinosteroids in Arabidopsis , 2003, Plant Physiology.

[11]  J. Chory,et al.  Steroid signaling in plants and insects--common themes, different pathways. , 2002, Genes & development.

[12]  S. Fujioka,et al.  Microarray Analysis of Brassinosteroid-Regulated Genes in Arabidopsis , 2002, Plant Physiology.

[13]  F. Nagy,et al.  Regulation of Transcript Levels of the Arabidopsis Cytochrome P450 Genes Involved in Brassinosteroid Biosynthesis1 , 2002, Plant Physiology.

[14]  Jia Li,et al.  BAK1, an Arabidopsis LRR Receptor-like Protein Kinase, Interacts with BRI1 and Modulates Brassinosteroid Signaling , 2002, Cell.

[15]  Zhi-Yong Wang,et al.  The GSK3-like kinase BIN2 phosphorylates and destabilizes BZR1, a positive regulator of the brassinosteroid signaling pathway in Arabidopsis , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[16]  J. Chory,et al.  BES1 Accumulates in the Nucleus in Response to Brassinosteroids to Regulate Gene Expression and Promote Stem Elongation , 2002, Cell.

[17]  J. Chory,et al.  Nuclear-localized BZR1 mediates brassinosteroid-induced growth and feedback suppression of brassinosteroid biosynthesis. , 2002, Developmental cell.

[18]  Jianming Li,et al.  Regulation of Brassinosteroid Signaling by a GSK3/SHAGGY-Like Kinase , 2002, Science.

[19]  J. Chory,et al.  BIN2, a new brassinosteroid-insensitive locus in Arabidopsis. , 2001, Plant physiology.

[20]  J. Chory,et al.  BRI1 is a critical component of a plasma-membrane receptor for plant steroids , 2001, Nature.

[21]  T. Altmann.  A tale of dwarfs and drugs: brassinosteroids to the rescue. , 1998, Trends in genetics : TIG.

[22]  F. Nagy,et al.  Transcription of the Arabidopsis CPD gene, encoding a steroidogenic cytochrome P450, is negatively controlled by brassinosteroids. , 1998, The Plant journal : for cell and molecular biology.

[23]  S. Clouse,et al.  A Brassinosteroid-Insensitive Mutant in Arabidopsis thaliana Exhibits Multiple Defects in Growth and Development , 1996, Plant physiology.

[24]  Jonathan D. G. Jones,et al.  The tomato Dwarf gene isolated by heterologous transposon tagging encodes the first member of a new cytochrome P450 family. , 1996, The Plant cell.

[25]  F. Nagy,et al.  Brassinosteroids Rescue the Deficiency of CYP90, a Cytochrome P450, Controlling Cell Elongation and De-etiolation in Arabidopsis , 1996, Cell.

[26]  H. Weintraub,et al.  Differences and similarities in DNA-binding preferences of MyoD and E2A protein complexes revealed by binding site selection. , 1990, Science.