Annual Report 2006

Fig. 2
Map-based cloning of qSH1 and qSH1 expression
(A) Delimitation of qSH1 by a large scale linkage analysis.
(B) Neighbor-joining phylogenetic tree of BEL1-type homeobox genes found in and rice genomes.
(C) Complementation test for qSH1 gene. A 26-kb Kasalath fragment (TAC9) in TAC vector, pYLTAC7, was
transformed into Nipponbare. Top: Non-shattering degrees of T0 progeny were measured. Bottom: Lines 203 and
204 were partly transformed, because these lines lost the ORF region upon transformation.
(D) and (E) analysis of qSH1 expression at the abscission layer Nipponbare and NIL, respectively.
(or abscission layer) alongside the valve in the
fruit (silique), which originates from the carpels.
To verify the function of candidate gene, we
introduced ten of 10- to 25-kb Kasalath genomic
fragments scanning the predicted ORF and the
SNP into the non-shattering Nipponbare
cultivar (Fig. 2C). Only transgenic lines that
contained the Kasalath fragment with both the
ORF and the SNP exhibited complete seed
shattering, although one fragment, which
contained a full ORF region but not the SNP,
partly complemented the phenotype (Fig. 2C).
hybridization analysis revealed that,
in Nipponbare, the ORF was expressed in the
rachis meristem (Fig. 2D), but it was not
expressed in the provisional abscission layer
(Fig. 2D). On the other hand, in the NIL the
ORF was expressed at the stage of
establishment of the rachis meristem (Fig. 2E),
the stage of differentiation of glumes and
formation of the provisional abscission layer at
the base of the spikelet (Fig. 2E), and the stage
of rapid elongation of rachis and branches (Fig.
2E). We therefore concluded that this
ortholog was the gene and that the
identified SNP affected only the spatial mRNA
expression pattern of , which was lost at
the abscission layer in Nipponbare.
Flowering-time control of rice
We have previously identified that a novel
B-type response regulator, promote
flowering mainly under short-day conditions
(Doi 2004). encodes a B type
response regulator, which consists of one
receiver and one GARP DNA binding domain.
mRNA was induced by short-day
treatments and exhibited two peaks a day; one
before dawn and the other after dawn. This
indicates that both photo signal transduction