Abstract
The architecture of rice is affected by organs differentiated from axillary meristems. LAX is essential for initiation of axillary meristems and lax has reduced number of lateral organs in the panicle. LAX, expressed in an adaxial boundary of the axillary meristem, encodes a bHLH transcription factor. However, on the basis of amino acid sequence, it is predicted that LAX does not bind to DNA and functions as an inhibiter of another bHLH protein through formation of a heterodimer. To determine its function at molecular level, we are studying genes working downstream of LAX and directly controlled by LAX. We are also identifying heterodimer partners of LAX. A microarray analysis through an induction system showed that LAX induces various transcription factors and auxin signaling genes. This result suggests a possibility that LAX mediates auxin signaling pathway at a boundary of the axillary meristem.
