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Plant Gene and Trait 2012, Vol.3, No.5, 22
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of
Arabidopsis
appeared polymorphism. Online BLAST
analysis revealed that the sequence similarity between
cloned
pAtAP3
and BAC clone (AL132971) from
9 264 to 11 030 in No. 3 chromosome of
Arabidopsis
ecotype (Col) was up to 100%, and its downstream
sequence of the cloned promoter exactly encoded
APETALA3
. Therefore, the cloned sequence was iden-
tified as the
AP3
promoter of
Arabidopsis
ecotype
(Col), and the GenBank accession No. was FJ619533.
Online PLACE analysis showed that there was a
TATA box (TTATTT) between nucleotide 1 205 bp to
1 210 bp, whose function was to ensure the accurate
transcription start. It also contained 6 CAAT boxes,
from 154 bp to 157 bp, 328 bp to 331 bp, 878 bp to
881 bp, 1 252 bp to 1 255 bp, 1 469 bp to 1 472 bp and
1 619 bp to 1 622 bp, respectively, which determined
the start frequency of the promoter. Three conserved
elements CArG-box binding to MADS-box protein in
pAtAP3
were directly related to the specific expression
of
AP3
gene in petals and stamens (Koch et al., 2001;
Tilly et al., 1998). CArG1
-
box (GTTTACATAAAT
GGAAAA), located from 1 551 bp to 1 568 bp, was
the binding sites of heterodimer AP3/PI. If the
cis
-element of CArG2
-
box (CTTACCTTTCATGGAT
TA) which was located from bp 1 599 to 1 616 bp was
mutated, it can lead to lowwer expression of
AP3
gene
in petals, but without any changes in stamens. The 3
rd
CArG3
-
box (CTTTCCATTTTTAGTAAC) was located
from 1 624 bp to 1 641 bp. Two anther box (AGAAA)
located from 114 bp to 118 bp and from 955 bp to
959 bp, respectively, were the core
cis
-elements of
AP3
promoter specifically expressed in stamen (Tunen
et al., 1989). However, the G-box (Staiger et al., 1989)
and TACPyAT-box elements (van der Meer et al.,
1992) contained in promoter of
CHS
gene from
Petunia were not detected in
pAtAP3
.
Figure 3 Sequence of
pAtAP3
Note: Boxes indicate the flower specific expression element of
pAtAP3
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