Abstract
The typical body plan of higher plants is composed of the main axis attached by numerous lateral organs. Formation of lateral organs creates boundaries that separate the primodia from the tissue of the main axis. The role of the boundaries in lateral organ formation is not well understood. In the puchi mutant of Arabidopsis, ectopic bracts and spitules are formed at the base of flower primordia. In addition, the base of lateral roots is expanded in puchi, mainly due to an increased number of cells. We cloned the PUCHI gene and it encodes a putative transcription factor. PUCHI expression is detected in the boundary between the inflorescence meristem and flower primordia, and between the primary root and lateral root primordia. These results suggest that PUCHI functions in the boundaries to repress bract and spitule formation in flowers and restricts cell proliferation at the base of lateral root primordia.
