Abstract
Shoot branching is ultimately important for the establishment of plant architecture We analyzed five tillering dwarf mutants that exhibit reduction of plant stature and increase in tiller numbers. We show that, in the mutants, axillary meristems are normally established but the suppression of tiller bud activity is weakened. The phenotypes of tillering dwarf mutants suggest that they play roles in the control of tiller bud dormancy to suppress bud activity. However, tillering dwarf mutants show the dependence of both node position and planting density on their growth, which implies that the functions of tillering dwarf genes are independent of the developmental and environmental control of bud activity. Map-based cloning of the D3 gene revealed that it encodes an F-box LRR protein orthologous to Arabidopsis MAX2. This indicates the conservation of mechanisms controlling axillary bud activity between monocots and eudicots.
