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Updated: Aug 10, 2026
10:24
A Method for Characterizing Embryogenesis in Arabidopsis
Published on: August 4, 2017
The TORNADO1 and TORNADO2 genes function in several patterning processes during early leaf development in Arabidopsis
Gerda Cnops1, Pia Neyt, Jeroen Raes
1Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, B-9052 Gent, Belgium.
The Plant Cell
|March 15, 2006
Summary
The TORNADO1 (TRN1) and TRN2 genes in Arabidopsis thaliana are crucial for leaf patterning, affecting venation complexity and symmetry. Mutations disrupt cell growth balance, leading to abnormal leaf development and vascular networks.
Area of Science:
- Plant biology
- Developmental genetics
- Molecular plant science
Background:
- Patterning is fundamental for multicellular organism development, establishing body axes, organ domains, and cell differentiation.
- Leaf development involves intricate processes of patterning, including lamina venation, symmetry, and lateral growth.
Purpose of the Study:
- To identify and characterize the roles of Arabidopsis thaliana TORNADO1 (TRN1) and TRN2 genes in leaf patterning.
- To investigate the molecular mechanisms underlying leaf asymmetry and aberrant venation in trn mutants.
Main Methods:
- Mutant analysis of Arabidopsis thaliana (trn1, trn2, and double mutants).
- Phenotypic characterization of leaf venation, symmetry, and growth.
- Gene expression analysis and protein domain identification for TRN1 and TRN2.
Main Results:
- Mutations in TRN1 and TRN2 resulted in severely reduced leaf venation complexity, including incomplete loops and vascular islands.
- trn mutants exhibited asymmetric and narrow leaf laminas due to reduced cell number and altered cell proliferation/differentiation balance.
- TRN1 and TRN2 function in the same genetic pathway and are epistatic to ASYMMETRIC LEAVES1 regarding leaf asymmetry.
Conclusions:
- TRN1 and TRN2 play essential roles in establishing leaf polarity, venation patterns, and overall leaf morphology.
- Imbalances in cell proliferation, differentiation, and altered auxin distribution are likely causes of aberrant leaf development in trn mutants.
- TRN1 encodes a plant-specific signaling protein, while TRN2 is a transmembrane tetraspanin protein, both acting in a conserved developmental pathway.
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