Termination of stem cell maintenance in Arabidopsis floral meristems by interactions between WUSCHEL and AGAMOUS.
Floral meristems and shoot apical meristems (SAMs) are homologous, self-maintaining stem cell systems. Unlike SAMs, floral meristems are determinate, and stem cell maintenance is abolished once all floral organs are initiated. To investigate the underlying regulatory mechanisms, we analyzed the interactions between WUSCHEL (WUS), which specifies stem cell identity, and AGAMOUS (AG), which is required for floral determinacy. Our results show that repression of WUS by AG is essential for terminating the floral meristem and that WUS can induce AG expression in developing flowers. Together, this suggests that floral determinacy depends on a negative autoregulatory mechanism involving WUS and AG, which terminates stem cell maintenance.
Lenhard
M
M
Universität Tübingen, ZMBP--Entwicklungsgenetik, Auf der Morgenstelle 3, D-72076 Tübingen, Germany.
Bohnert
A
A
Jürgens
G
G
Laux
T
T
D026342:AGAMOUS Protein, Arabidopsis; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D018519:Meristem / Q000166:cytology / Q000502:physiology*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018514:Plant Structures / Q000502:physiology* / Q000648:ultrastructure; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors
D026342:AGAMOUS Protein, Arabidopsis; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C074747:LFY protein, Arabidopsis; D010940:Plant Proteins; D014157:Transcription Factors; C116421:WUSCHEL protein, Arabidopsis