AGAMOUS terminates floral stem cell maintenance in Arabidopsis by directly repressing WUSCHEL through recruitment of Polycomb Group proteins.
Floral stem cells produce a defined number of floral organs before ceasing to be maintained as stem cells. Therefore, floral stem cells offer an ideal model to study the temporal control of stem cell maintenance within a developmental context. AGAMOUS (AG), a MADS domain transcription factor essential for the termination of floral stem cell fate, has long been thought to repress the stem cell maintenance gene WUSCHEL (WUS) indirectly. Here, we uncover a role of Polycomb Group (PcG) genes in the temporally precise repression of WUS expression and termination of floral stem cell fate. We show that AG directly represses WUS expression by binding to the WUS locus and recruiting, directly or indirectly, PcG that methylates histone H3 Lys-27 at WUS. We also show that PcG acts downstream of AG and probably in parallel with the known AG target KNUCKLES to terminate floral stem cell fate. Our studies identify core components of the network governing the temporal program of floral stem cells.
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, California 92521, USA.
Xigang
X
Liu
Yun Ju
YJ
Kim
Ralf
R
Müller
Rae Eden
RE
Yumul
Chunyan
C
Liu
Yanyun
Y
Pan
Xiaofeng
X
Cao
Justin
J
Goodrich
Xuemei
X
Chen
D026342:AGAMOUS Protein, Arabidopsis / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002874:Chromosome Mapping; D035264:Flowers / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D056426:Genetic Loci / Q000235:genetics; D006657:Histones / Q000737:chemistry; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D018519:Meristem / Q000166:cytology; D008954:Models, Biological; D016296:Mutagenesis; D009154:Mutation; D010641:Phenotype; D030821:Plants, Genetically Modified; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D036226:Seedlings / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D013234:Stem Cells / Q000502:physiology*
D026342:AGAMOUS Protein, Arabidopsis; D029681:Arabidopsis Proteins; C104597:CURLY LEAF protein, Arabidopsis; D002352:Carrier Proteins; D006657:Histones; D018398:Homeodomain Proteins; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; C116421:WUSCHEL protein, Arabidopsis; C491031:knuckles protein, Arabidopsis