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The evolution of apical dominance in maize
1Department of Plant Biology, University of Minnesota, St Paul 55108, USA. jdoebley@maroon.tc.umn.edu
Nature
|April 3, 1997
Summary
The teosinte branched1 (tb1) gene in maize controls apical dominance, increasing the main stem
Area of Science:
- Plant genetics
- Evolutionary biology
- Crop domestication
Background:
- Crop domestication often increases apical dominance, suppressing side branches.
- Maize (Zea mays spp. mays) shows greater apical dominance than its ancestor, teosinte (Zea mays ssp. parviglumis).
- The teosinte branched1 (tb1) gene is key to this evolutionary shift.
Purpose of the Study:
- To clone the tb1 gene and understand its role in maize domestication.
- To investigate the molecular mechanisms behind the increased apical dominance in maize.
Main Methods:
- Cloning the tb1 gene using transposon tagging.
- Analyzing tb1 gene expression patterns.
- Examining the morphology of tb1 mutant plants.
Main Results:
- The tb1 gene encodes a protein homologous to snapdragon's cycloidea gene.
- tb1 expression represses axillary organ growth and promotes female inflorescence formation.
- The maize tb1 allele is expressed at double the level of the teosinte allele.
Conclusions:
- Gene regulatory changes in tb1 underlie the evolutionary divergence of maize from teosinte.
- tb1 plays a crucial role in shaping maize architecture during domestication.