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.
He
Jun-Xian
JX
Department of Plant Biology, Carnegie Institution, Stanford, CA 94305, USA.
Gendron
Joshua M
JM
Sun
Yu
Y
Gampala
Srinivas S L
SS
Gendron
Nathan
N
Sun
Catherine Qing
CQ
Wang
Zhi-Yong
ZY
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D006706:Homeostasis; D008027:Light; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010937:Plant Growth Regulators / Q000096:biosynthesis / Q000378:metabolism* / Q000494:pharmacology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D015398:Signal Transduction; D013256:Steroids / Q000096:biosynthesis / Q000378:metabolism* / Q000494:pharmacology; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; C454444:BZR1 protein, Arabidopsis; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D013256:Steroids