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Abstract Leaves and flowers are produced by the shoot apical meristem (SAM) at a certain distance from its center, a process that requires the hormone auxin. The amount of auxin and the pattern of its distribution in the initiation zone determine the size and spatial arrangement of organ primordia. Auxin gradients in the SAM are formed by PIN-FORMED (PIN) auxin efflux carriers whose polar localization in the plasma membrane depends on the protein kinase PINOID (PID). Previous work determined that ERECTA (ER) family genes (ERfs) control initiation of leaves. ERfs are plasma membrane receptors that enable cell-to-cell communication by sensing extracellular small proteins from the EPIDERMAL PATTERNING FACTOR/EPF-LIKE (EPF/EPFL) family. Here, we investigated whether ERfs regulate initiation of organs by altering auxin distribution or signaling in Arabidopsis (Arabidopsis thaliana). Genetic and pharmacological data suggested that ERfs do not regulate organogenesis through PINs while transcriptomics data showed that ERfs do not alter primary transcriptional responses to auxin. Our results indicated that in the absence of ERf signaling the peripheral zone cells inefficiently initiate leaves in response to auxin signals and that increased accumulation of auxin in the er erecta-like1 (erl1) erl2 SAM can partially rescue organ initiation defects. We propose that both auxin and ERfs are essential for leaf initiation and that they have common downstream targets. Genetic data also indicated that the role of PID in initiation of cotyledons and leaves cannot be attributed solely to regulation of PIN polarity and PID is likely to have other functions in addition to regulation of auxin distribution.
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Apical hook opening of plant seedlings: Unfolding the role of auxin and the cell wall
Apical hook opening is crucial for seedling establishment and is regulated by unequal distribution of the hormone auxin through unknown mechanisms. In this issue of Developmental Cell, Walia et al. 4 demonstrate that apical hook opening is an output of tissue-wide forces; auxin and cell wall integrity (CWI) signaling interact to restrict elongation to the concave side of the apical hook.
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- Award ID(s):
- 2410274
- PAR ID:
- 10587203
- Editor(s):
- Le_Good, Jessie_Ann
- Publisher / Repository:
- Cell Press
- Date Published:
- Journal Name:
- Developmental Cell
- Volume:
- 59
- Issue:
- 24
- ISSN:
- 1534-5807
- Page Range / eLocation ID:
- 3194 to 3196
- Subject(s) / Keyword(s):
- auxin development
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.devcel.2024.11.018
