Inflorescence Commitment and Architecture in
Arabidopsis
Desmond Bradley,
Oliver Ratcliffe,
Coral Vincent,
Rosemary Carpenter,
Enrico Coen
*
Flowering plants exhibit one of two types of inflorescence
architecture: indeterminate, in which the inflorescence grows
indefinitely, or determinate, in which a terminal flower is produced.
The indeterminate condition is thought to have evolved from the
determinate many times, independently. In two mutants in distantly
related species, terminal flower 1 in Arabidopsis
and centroradialis in Antirrhinum, inflorescences
that are normally indeterminate are converted to a determinate
architecture. The Antirrhinum gene CENTRORADIALIS (CEN) and the Arabidopsis gene TERMINAL
FLOWER 1 (TFL1) were shown to be homologous, which
suggests that a common mechanism underlies indeterminacy in these
plants. However, unlike CEN, TFL1 is also expressed during the vegetative phase, where it delays the commitment to inflorescence development and thus affects the timing of the formation of the inflorescence meristem as well as its identity.
D. Bradley, Sainsbury Laboratory, John Innes Centre, Colney Lane,
Norwich NR4 7UH, UK.
O. Ratcliffe, C. Vincent, R. Carpenter, E. Coen, Genetics Department,
John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
*
To whom correspondence should be addressed.
