INVESTIGADORES
DELGADO Luciana
artículos
Título:
FORMOSA controls cell division and expansion during floral development in Antirrhinum majus
Autor/es:
LUCIANA DELGADO BENARROCH; BARRY CAUSIER ·; JULIA WEISS; MARCOS EGEA-CORTINES
Revista:
PLANTA
Editorial:
SPRINGER
Referencias:
Año: 2009 vol. 229 p. 1219 - 1229
ISSN:
0032-0935
Resumen:
Control of organ size is the product of coordinated
cell division and expansion. In plants where one of
these pathways is perturbed, organ size is often unaffected
as compensation mechanisms are brought into play. The
number of founder cells in organ primordia, dividing cells,
and the period of cell proliferation determine cell number in
lateral organs. We have identiWed the Antirrhinum FORMOSA
(FO) gene as a specific regulator of floral size. Analysis
of cell size and number in the fo mutant, which has
increased flower size, indicates that FO is an organ-specific
inhibitor of cell division and activator of cell expansion.
Increased cell number in fo floral organs correlated with
upregulation of genes involved in the cell cycle. In Arabidopsis
the AINTEGUMENTA (ANT) gene promotes cell division.
In the fo mutant increased cell number also correlates
with upregulation of an Antirrhinum ANT-like gene (Am-
ANT) in inflorescences that is very closely related to ANT
and shares a similar expression pattern, suggesting that they
may be functional equivalents. Increased cell proliferation
is thought to be compensated for by reduced cell expansion
to maintain organ size. In Arabidopsis petal cell expansion
is inhibited by the BIGPETAL (BPE) gene, and in the fo
mutant reduced cell size corresponded to upregulation of an
Antirrhinum BPE-like gene (Am-BPE). Our data suggest
that FO inhibits cell proliferation by negatively regulating
Am-ANT, and acts upstream of Am-BPE to coordinate floral
organ size. This demonstrates that organ size is modulated
by the organ-specific control of both general and local gene
networks.