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Summary Meristem activity is controlled by the CLAVATA (CLV) signaling pathway, which involves a suite of leucine‐rich receptor (LRR) receptors, receptor‐like proteins, and CLV‐EMBRYO SURROUNDING REGION (CLE) peptide ligands. FASCIATED EAR 3 (FEA3) is a leucine‐rich receptor (LRR) receptor‐like protein important for meristem maintenance in maize and acts independently of canonical CLV receptors.To identify FEA3's interaction network, we used TurboID‐based proximity labeling inZea maysmeristems and identified a putative co‐receptor, BARELY ANY MERISTEM 1D (BAM1D).BAM1D and FEA3 proximity labeling proteomes shared over 40 proteins, including many signaling proteins, suggesting they feed into a common signaling pathway.fea3was epistatic tobam1din the control of inflorescence meristem (IM) size, supporting the idea that FEA3 and BAM1D interact physically. However,fea3andbam1dact antagonistically becausefea3mutants had larger IMs, whereasbam1dmutants produced smaller IMs.This study demonstrates howin vivoTurboID‐based proximity labeling clarifies complex genetic interactions between CLV receptors and expands our knowledge of downstream signaling components of CLV signaling pathways, which are largely uncharacterized. Our findings support the notion that multiple, partially overlapping CLV receptor complexes coordinately control meristem maintenance.
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This content will become publicly available on April 1, 2027
The role of SIAMESE in G2 checkpoint regulation in Arabidopsis thaliana
Summary Although the cell cycle is conserved between plants and other eukaryotes, there are also significant differences, particularly in G2 regulation. In particular, the WEE1/CELL DIVISION CYCLE25 (CDC25) circuit that establishes G2 timing in animals and fungi is absent in plants.InArabidopsis thaliana, SIAMESE (SIM), a well‐known regulator of endoreplication with homologs throughout land plants, is a cyclin‐dependent kinase (CDK) inhibitor that restricts progression through mitosis. Mathematical modeling indicated that SIM may modulate the length of G2 during mitotic cycles in addition to its role in endoreplication.This prediction was tested several ways. First, root growth ofsimlagged slightly behind that of wild‐type (WT) and the root meristem was longer insimthan in WT. Second, two independent methods of monitoring cell cycle phases, long‐term live‐cell imaging and 5‐ethynyl‐2‐deoxyuridine (EdU) pulse‐chase labeling, showed that G2 is shorter insimroot meristem cortex cells than in WT. Finally, fluorescence levels of a CYCB:GFP fusion that responds directly to G2 CDK activity were consistent withsimmutants having greater G2 CDK activity.These results suggest that, in addition to its role in endoreplication, SIM plays a role in determining the length of G2 during mitotic cycles, potentially substituting in part for the functions of WEE1/CDC25.
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- Award ID(s):
- 2320251
- PAR ID:
- 10682019
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 250
- Issue:
- 1
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- 261 to 271
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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