Abstract
The plant hormone auxin plays important roles in plant growth and development. One of the important genes involved in auxin function is Arabidopsis PINOID (PID), encoding a serine-threonine protein kinase. pid mutants are impaired in the ability to produce axillary organs. To elucidate the relationship between branching and auxin function in rice, we have analyzed rice PINOID gene (OsPID).
We isolated OsPID based on the similarity of amino acid sequences. OsPID is expressed in the shoot apex and roots, and in situ hybridization analysis revealed that OsPID mRNA accumulated in the leaf axil, where the axillary meristem differentiates. OsPID expression is induced by auxin without de novo protein biosynthesis. Overexpression of OsPID caused suppression of root formation, which is reminiscent of auxin treated plants. Our results suggest that OsPID plays a role in auxin signaling and might be involved in axillary meristem formation.
