Reference "The OsFOR1 gene encodes a polygalacturonase-inhibiting protein (PGIP) that regulates floral organ number in rice"

Reference ID

8170

Title

The OsFOR1 gene encodes a polygalacturonase-inhibiting protein (PGIP) that regulates floral organ number in rice

Source

Plant molecular biology, 2003, vol. 53, pp. 357-369

Authors (9)

Jang-S	Lee-B
Kim-C	Kim-S-J
Yim-J	Han-J-J
Lee-S	Kim-S-R
An-G

Abstract

We have isolated a cDNA clone, OsFOR1, from the immature panicles of rice. The
OsFOR1 (Oryza sativa floral organ regulator 1) gene encodes a protein that
contains a leucine-rich repeat (LRR) domain. This domain comprises 10 tandem
repeats of a canonical 24-amino acid LRR sequence. The structure and the number
of LRRs for OsFOR1 are similar to those of polygalacturonase-inhibiting proteins
(PGIPs) from various other plant species. Moreover, the OsFOR1 recombinant
protein, when fused to maltose-binding protein (MBP), shows PGIP activity
against the Aspergillus niger polygalacturonase. OsFOR1 is highly expressed in
the calli and immature and mature panicles, while detectable at only low levels
in seedling roots and mature stems. In situ hybridization experiments showed the
transcripts of OsFOR1 are present in young spikelet primordia and in almost all
of the young floral organs. Transgenic approaches were used to study in vivo
functioning. Antisense expression of OsFOR1 resulted in an increase in the
numbers of floral organs, including the stamen, carpel, palea/lemma, stigma, and
lodicule. OsFOR1 transcript was not detected in the frizzy panicle mutant, which
is defective in its spikelet formation but normal in inflorescence-meristem
initiation and maintenance. Therefore, we suggest that OsFOR1 plays a role in
the formation and/or maintenance of floral organ primordia.