Abstract
Shoot branching plays important roles in establishing diverse plant architecture. This process generally involves two steps, the formation of axillary meristems and the outgrowth of axillary buds. In rice plants, axillary buds grow as tillers during vegetative phase. Although tillering affects rice yield greatly, little is known about underlying mechanisms controlling tillering at molecular level.
We analyzed five rice mutants; d3, d10, d14, d17, and d27 , which exhibit dwarf and increased tillering. These mutants normally establish axillary buds in leaf axils. The phenotype of these mutants suggests that these tillering dwarf genes are required to suppress the outgrowth of buds. Map-based cloning of D3 and D10 revealed that D3 encodes an F-box Leucine Rich Repeat (LRR) protein orthologus to Arabidopsis MAX2and D10 encodes a Carotenoid Cleavage Deoxygenase (CCD) orthologus to MAX4/RMS1. These results firmly indicate the conservation of mechanisms controlling axillary buds activity between monocots and eudicots.
