The Transcriptional Coregulator LEUNIG_HOMOLOG Inhibits Light-Dependent Seed Germination in Arabidopsis.
PHYTOCHROME-INTERACTING FACTOR1 (PIF1) is a basic helix-loop-helix transcription factor that inhibits light-dependent seed germination in Arabidopsis thaliana. However, it remains unclear whether PIF1 requires other factors to regulate its direct targets. Here, we demonstrate that LEUNIG_HOMOLOG (LUH), a Groucho family transcriptional corepressor, binds to PIF1 and coregulates its targets. Not only are the transcriptional profiles of the luh and pif1 mutants remarkably similar, more than 80% of the seeds of both genotypes germinate in the dark. We show by chromatin immunoprecipitation that LUH binds a subset of PIF1 targets in a partially PIF1-dependent manner. Unexpectedly, we found LUH binds and coregulates not only PIF1-activated targets but also PIF1-repressed targets. Together, our results indicate LUH functions with PIF1 as a transcriptional coregulator to inhibit seed germination.
Department of Biological Sciences, KAIST, Daejeon 305-701, Korea.
Nayoung
N
Lee
Department of Biological Sciences, KAIST, Daejeon 305-701, Korea.
Jeongmoo
J
Park
Department of Biological Sciences, KAIST, Daejeon 305-701, Korea.
Keunhwa
K
Kim
Department of Biological Sciences, KAIST, Daejeon 305-701, Korea gchoi@kaist.edu.
Giltsu
G
Choi
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics* / Q000528:radiation effects; D015151:Immunoblotting; D008027:Light; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D012097:Repressor Proteins; C560407:LUH protein, Arabidopsis; C508068:At2g20180 protein, Arabidopsis