A cis cold memory element and a trans epigenome reader mediate Polycomb silencing of FLC by vernalization in Arabidopsis.
Some plants acquire competence to flower in spring after experiencing a seasonal temperature drop-winter cold, in a process termed vernalization. In Arabidopsis thaliana, prolonged exposure to cold induces epigenetic silencing of the potent floral repressor locus FLOWERING LOCUS C (FLC) by Polycomb group (PcG) proteins, and this silencing is stably maintained in subsequent growth and development upon return to warm temperatures. Here we show that a cis-regulatory DNA element in the nucleation region for PcG silencing at FLC and two homologous trans-acting epigenome readers, VAL1 and VAL2, control vernalization-mediated FLC silencing. The sequence-specific readers recognize both the cis element (termed the cold memory element) and a repressive mark, trimethylation of histone H3 at lysine 27 (H3K27me3), and directly associate with LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), leading to establishment of the H3K27me3 peak in the nucleation region at FLC during vernalization. Thus, our work describes a mechanism for PcG-mediated silencing by a DNA sequence-specific epigenome reader.
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.|Department of Biological Sciences, National University of Singapore, Singapore.
Wenya
W
Yuan
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Xiao
X
Luo
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Zicong
Z
Li
Department of Biological Sciences, National University of Singapore, Singapore.
Wannian
W
Yang
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Yizhong
Y
Wang
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Rui
R
Liu
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Jiamu
0000-0002-1337-0786
J
Du
Shanghai Center for Plant Stress Biology, CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.|Department of Biological Sciences, National University of Singapore, Singapore.
Yuehui
0000-0003-3304-4555
Y
He
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D003080:Cold Temperature; D044127:Epigenesis, Genetic / Q000235:genetics*; D035264:Flowers / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D018745:Genome, Plant; D026161:MADS Domain Proteins / Q000235:genetics*; D063146:Polycomb-Group Proteins / Q000235:genetics*; D020218:Response Elements / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D029681:Arabidopsis Proteins; C418902:At5g10140 protein, Arabidopsis; D026161:MADS Domain Proteins; D063146:Polycomb-Group Proteins