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Organ initiation from the shoot apical meristem first gives rise to leaves during vegetative development and then flowers during reproductive development.LEAFY(LFY) is activated after floral induction and together with other factors promotes the floral program. LFY functions redundantly with APETALA1 (AP1) to activate the class B genesAPETALA3(AP3) andPISTILLATA(PI), the class C geneAGAMOUS(AG), and the class E geneSEPALLATA3, which leads to the specification of stamens and carpels, the reproductive organs of flowers. Molecular and genetic networks that control the activation ofAP3,PI,andAGin flowers have been well studied; however, much less is known about how these genes are repressed in leaves and how their repression is lifted in flowers. Here, we showed that two genes encodingArabidopsisC2H2 ZINC FINGER PROTEIN (ZFP) transcription factors, ZP1 and ZFP8, act redundantly to directly repressAP3,PI,andAGin leaves. AfterLFYandAP1are activated in floral meristems, they down-regulateZP1andZFP8directly to lift the repression onAP3,PI,andAG. Our results reveal a mechanism for how floral homeotic genes are repressed and derepressed before and after floral induction.
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This content will become publicly available on January 22, 2027
ZINC FINGER PROTEIN 1 and 8 interact with polycomb repressive complex 2 to repress class B and C floral organ identity genes
Abstract Precise control of gene expression is essential for establishing and maintaining cell identities in response to endogenous signals and environmental cues in multicellular organisms. An example is the regulation of the class B and C floral organ identity genes—APETALA3 (AP3), PISTILLATA (PI), and AGAMOUS (AG)—which are repressed in leaves and activated in floral meristems. Their repression in leaves is associated with CURLY LEAF (CLF), a core component of the polycomb repressive complex 2 (PRC2). However, since CLF is expressed in both leaf and floral primordia, its target specificity is likely mediated by additional factors. In this study, we found that ZINC FINGER PROTEIN 1 (ZP1) and ZFP8 physically interact with PRC2 components CLF, SWINGER (SWN), and FERTILIZATION-INDEPENDENT ENDOSPERM (FIE) to repress AP3, PI, and AG. In plants ectopically expressing ZP1 and ZFP8, loss of CLF partially restored floral organ identity and reactivated the expression of AP3, PI, and AG, indicating that this repression is PRC2-dependent. Functional studies revealed that the zinc finger domain is necessary and sufficient for ZFP8 activity, whereas both the zinc finger and EAR domains are required for ZP1 function.
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- Award ID(s):
- 1947274
- PAR ID:
- 10681776
- Publisher / Repository:
- Oxford Academic
- Date Published:
- Journal Name:
- Nucleic Acids Research
- Volume:
- 54
- Issue:
- 3
- ISSN:
- 0305-1048
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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