Abstract
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.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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AGAMOUS Protein, Arabidopsis / genetics*
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AGAMOUS Protein, Arabidopsis / metabolism
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Arabidopsis / cytology
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Arabidopsis / genetics
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Arabidopsis / growth & development
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Arabidopsis / physiology*
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism*
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Carrier Proteins / genetics
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Carrier Proteins / metabolism
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Chromosome Mapping
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Flowers / cytology
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Flowers / genetics
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Flowers / growth & development
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Flowers / physiology
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Gene Expression Regulation, Developmental / physiology
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Gene Expression Regulation, Plant / physiology*
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Genetic Loci / genetics
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Histones / chemistry
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Homeodomain Proteins / genetics
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Homeodomain Proteins / metabolism*
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In Situ Hybridization
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Meristem / cytology
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Models, Biological
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Mutagenesis
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Mutation
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Phenotype
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Plants, Genetically Modified
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Polycomb-Group Proteins
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Repressor Proteins / genetics
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Repressor Proteins / metabolism*
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Seedlings / cytology
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Seedlings / genetics
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Seedlings / growth & development
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Seedlings / physiology
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Stem Cells / physiology*
Substances
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AGAMOUS Protein, Arabidopsis
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Arabidopsis Proteins
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CURLY LEAF protein, Arabidopsis
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Carrier Proteins
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Histones
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Homeodomain Proteins
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Polycomb-Group Proteins
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Repressor Proteins
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WUSCHEL protein, Arabidopsis
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knuckles protein, Arabidopsis