The life cycle of land plants is characterized by alternating generations of sexual gametophytes and asexual sporophytes. Unlike seed plants, seed-free vascular plants, including ferns, initiate and maintain pluripotent meristems during their gametophyte phase to sustain body expansion and drive the formation of sexual organs for reproduction. This review summarizes meristem development among various fern species during the gametophyte phase, focusing on the cellular basis of meristem initiation, proliferation, and termination. We review the different types of gametophytic meristems in ferns, including apical cell (AC)-based meristems, multicellular apical meristems, and multicellular marginal meristems. We highlight both conserved and lineage-specific patterns of cell division, which are closely associated with these meristem identities and play crucial roles in shaping gametophytic morphology. Additionally, we highlight recent progress in understanding the dynamics of cell division and growth that drive meristem development, through studies that integrate confocal live imaging and computational quantitative analysis. Furthermore, we discuss the influence of environmental and genetic factors on cell division activity in fern gametophytes, including conserved transcriptional regulators that sustain meristem indeterminacy and proliferation in the model fern Ceratopteris richardii.
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Tuber, or not tuber: Molecular and morphological basis of underground storage organ development
Underground storage organs occur in phylogenetically diverse plant taxa and arise from multiple tissue types including roots and stems. Thickening growth allows underground storage organs to accommodate carbohydrates and other nutrients and requires proliferation at various lateral meristems followed by cell expansion. The WOX-CLE module regulates thickening growth via the vascular cambium in several eudicot systems, but the molecular mechanisms of proliferation at other lateral meristems are not well understood. In potato, onion, and other systems, members of the phosphatidylethanolamine-binding protein (PEBP) gene family induce underground storage organ development in response to photoperiod cues. While molecular mechanisms of tuber development in potato are well understood,we lack detailed mechanistic knowledge for the extensive morphological and taxonomic diversity of underground storage organs in plants.
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- PAR ID:
- 10531781
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Current Opinion in Plant Biology
- Volume:
- 80
- Issue:
- C
- ISSN:
- 1369-5266
- Page Range / eLocation ID:
- 102544
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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