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Plant Gene and Trait 2012, Vol.3, No.3, 13
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Figure 4 Agarose gel electrophoresis of RT-PCR for calmodulin
gene expression
the expression of CaM increased sharply at 24 h.
Treated by ethylene and A23178 (Ca
2+
accelerator),
the peak expression increased obviously early at 6 h.
When treated by ethylene with W7 or TFP (Ca
2+
agonist), the expression of CaM increasing remarkable
delayed to 48 h or later. When treated by ethylene
with EGTA (Ca
2+
chelant) the expression of CaM
increasing evidently delayed to 72 h (Figure 5).
Figure 5 Northern blot analysis of expression characteristics of
calmodulin in
Guzmania
‘Amaranth’ treated with ethylene,
ethylene and Ca
2+
regulators
1.3 Effect of Ca
2+
regulator on
G.
‘Amaranth’
flowering
We investigated the flower process by using anatomy
methods. The results indicated that ethylene with
A23178 could advance the flowering formation 5 d
early than that only treated by ethylene. However,
Ca
2+
agonist and Ca
2+
chelant both could delay the
flowering formation (Figure 6).
Figure 6 Time of flower organ arising of calmodulin in
Guzmania ‘Amaranth’ treated with ethylene, ethylene and Ca
2+
regulators
Note: EW: Ethylene+W7; ET: Ethylene+TFP; EE: Ethylene+
EGTA; EA: Ethylene+A23187; E (CK): Ethylene
2 Discussion
Calcium (Ca
2+
) is not only an important nutrient
element, but also plays important roles in plant
developmental via a group of Ca
2+
target proteins,
including CaM and Ca
2+
-dependent protein kinases
(CDPKs).
Flowering is the key physiological feature of plants.
Early reports indicated that the CaM which has the
most content at the initiation of flower mainly involved
in the launch of flower buds in
Pyrus pyrifolia
Nakai
cv. Huanghua (Peng et al., 1998). Ca
2+
regulators,
including Ca
2+
accelerator, Ca
2+
agonist and Ca
2+
chelant, all affected the flower bud differentiation of
strawberry (Luo et al., 2001). In this study, we isolated
CaM
gene fragment from
G.
‘Amaranth’ which had
high homology with those CaM registered in GenBank.
During the
G.
‘Amaranth’ flower process induced with
ethylene, the expression changed like unimodal curve,
the maximum value appeared at 24 h. A23178, Ca
2+
accelerator, brought the maximum value forward to
6 h, while the Ca
2+
agonist and Ca
2+
chelant both
delayed it to 72 h or later. Accordingly, the Ca
2+
regulators affected the formation time of floral organ.
Ca
2+
accelerator promoted the formation of floral
organ, but others delayed the floral organ development.
Therefore, Ca
2+
regulators might affected the Ca
2+
contents (Peng et al., 1998; Yi et al., 2011), which
influence the expression of CaM and CaM contents
accordingly (Yi et al., 2011), and finally affected the
flower process of
G.
‘Amaranth’ (Yi et al., 2010). On