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Updated: May 1, 2026
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Published on: January 14, 2016
Interaction between two timing microRNAs controls trichome distribution in Arabidopsis
Xue-Yi Xue1, Bo Zhao1, Lu-Men Chao1
1National Key Laboratory of Plant Molecular Genetics and National Plant Gene Research Center, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China.
Lost meristems (LOM) proteins regulate plant age and development by interacting with squamosa promoter binding protein-like (SPL) transcription factors. This interaction controls trichome formation and phase transition, revealing a novel miRNA-mediated feedback loop.
Area of Science:
- Plant Molecular Biology
- Developmental Biology
- Genetics
Background:
- Squamosa promoter binding protein-like (SPL) transcription factors act as endogenous age cues, governing plant phase transition and morphogenesis.
- The precise mechanisms controlling SPL activity and its downstream effects, particularly in phase-dependent morphogenesis like trichome patterning, are not fully understood.
Purpose of the Study:
- To investigate the role of miR171-targeted Lost meristems (LOM) proteins in regulating SPL activity and plant phase transition.
- To elucidate the molecular mechanisms underlying LOM-mediated control of trichome formation in Arabidopsis thaliana.
Main Methods:
- Analysis of LOM gene function through overexpression of miR171 and constitutive expression of miR171-resistant LOM (rLOM) genes.
- Genetic analysis to determine the dependency of LOMs on SPLs for trichome distribution.
- Investigation of physical interactions between LOM and SPL proteins using biochemical assays.
- Examination of the feedback loop between LOMs and MIR171 gene expression.
Main Results:
- Reduced LOM abundance decreased trichome density, while enhanced LOM expression promoted trichome production, indicating LOMs promote trichome initiation.
- LOMs regulate trichome distribution in a SPL-dependent manner, with SPLs positively controlling trichome repressor genes TCL1 and TRY.
- Physical interaction between LOM N-termini and SPLs leads to the repression of SPL activity.
- LOM-SPL interaction influences other developmental events, including flowering, and MIR171 expression is regulated by LOMs, forming a feedback loop.
Conclusions:
- Lost meristems (LOM) proteins are key regulators of plant phase transition and morphogenesis by modulating SPL transcription factor activity.
- An antagonistic interplay between miR156 and miR171, mediated by their targets SPLs and LOMs respectively, controls plant growth and development.
- The LOM-SPL interaction reveals a conserved mechanism for integrating age-related signals and developmental timing in plants.
