S. Balasubramanian et K. Schneitz, NOZZLE regulates proximal-distal pattern formation, cell proliferation andearly sporogenesis during ovule development in Arabidopsis thaliana, DEVELOPMENT, 127(19), 2000, pp. 4227-4238
With the characterisation of the NOZZLE gene we aim at a better understandi
ng of the molecular and genetic mechanism underlying pattern formation and
growth control during floral organogenesis, Our data indicate that NOZZLE l
inks these processes during ovule development. In the ovule primordium NOZZ
LE plays a central role in the formation of the nucellus through antagonizi
ng the activities of BELL, AINTEGUMENTA and INNER NO OUTER, all encoding pu
tative transcription factors, in the prospective nucellar region. We provid
e evidence that NOZZLE and BELL are chalaza identity genes that share overl
apping functions in establishing the prospective chalaza of the ovule. In a
ddition, NOZZLE plays a role in controlling the cell number and by this mea
ns the length of the funiculus, again through antagonizing AINTEGUMENTA and
INNER NO OUTER function. NOZZLE is also required for the development of th
e integuments. We show that during the initial phase of this process NOZZLE
is transcriptionally regulated by AINTEGUMENTA and INNER NO OUTER. NOZZLE
thus represents a downstream target of these two genes in the integument de
velopment pathway.