基本HTML版本
Genomics and Applied Biology 2014, Vol. 5, No. 2, 1-6
http://gab.biopublisher.ca
2
Studies show that the main form of storage proteins is
arginine in the plant seed (Chat Thai and Misra,
1998; King and Gifford, 1997). During the seed
germination period, a large number of storage
proteins degraded, and we can detect a significant
increase in arginine content (Herman and Larkins,
1999). For example, during the seed germination
of Loblolly Pine (
Pinus taeda L.
), the storage
proteins existing in megagametophyte degraded, and
then the amino acid content of seedings increased
largely. Among the amino acid, the part of arginine is
the most, almost accounted for half of the nitrogen
storage in the storage proteins in megagametophyte
(King and Gifford, 1997). Consequently, we can know
that arginine play an important role in seed
germination progress.
Arginase (E. C. 3. 5. 3. 1) is an enzyme contained
manganese metal, and it has three subunits, each of
which requires two Mn atoms, and arginase specificity
catalyzes L-arginine into L-ornithine and urea (da
Silva
et al.,
2008; Di Costanzo
et al.,
2005;
Reczkowski and Ash, 1992). Currently, the arginase
of many plants has been studied. In soybean, there is a
sharp increase expression during germination period,
which reached the maximum 3 or 5 days later after
germination (Goldraij and Polacco, 1999); In rice, the
only arginase gene plays a key role in the
development of panicles and grain yield, especially
when the external source of nitrogen deficiency (Ma
et
al.,
2013); There are two argianse genes in tomato
-
LeARG1
,
LeARG2
, both of which are abundantly
expressed in reproductive tissues such as the bud, not
open mature flowers, already open matured flowers
and unripe fruits (Chen
et al.,
2004; Alabadí et al.,
1996)); In
Arabidopsis thaliana
, there are two
arginase genes which has been cloned, namely
ARGAH1
,
ARGAH2
(Flores
et
al.,
2008;
Krumpelman
et al.,
1995).
ARGAH1
can be
transcripted and expressed (Flores
et al.,
2008). And
the expressing of
ARGAH2
is induced by
Botrytis
cinerea
and methyl jasmonate (Brauc
et al.,
2012;
Brownfield
et al.,
2008); during germination and
post-germination in loblolly pine, the arginase activity
is also increased largely, accompanying with the
increase of arginase gene expressing (King and
Gifford, 1997; Todd
et al.,
2001). In addition, argianse
activity has a rapid increase during the germination in
many plants, such as pumpkin (Splittstoesser, 1969),
broad bean (Kollöffel and van Dijke, 1975), soybean
(Kang and Cho, 1990),
Arabidopsis thaliana
(Zonia
et al.,
1995).
In addition, it is reported that arginase has a response
to various biotic stresses and abiotic stress through the
regulation of arginine metabolism and polyamine
pathway. For example, the mutant of
Arabidopsis
thaliana
arginase accumulated less ROS, which
indicated that inhibiting the expression of
ARGAHs
can improve the tolerance to dehydration, high salt
stress and chilling stress (Shi and Chan, 2013).
Furthermore, Brown and his team have found out that
Botrytis cinere
induced the expression of
ARGAH2
and the increase expression of
ARGAH2
increased the
tolerance to
Botrytis cinere
in
Arabidopsis thaliana
(Brauc
et al.,
2012; Brownfield
et al.,
2008). Similar
to this, previous studies have shown that the deletion
mutant of
ARGAHs
genes led to an increase
accumulation of nitric oxide, and the overexpression
of
ARGAH2
enhanced the development of callus
tissue when the plant is infected by Clubroot. In
tomato, the expression of
LeARG2
is induced by
wounding. However,
LeARG1
is not (Chen
et al.,
2004).
In conclusion, we can summarize that arginase genes
are largely expressed during seed germination, and
arginase plays a role in the response to many adversity
stresses in plants.
In this study, we take Columbia-type
Arabidopsis
as
experimental material. By the means of real-time
fluorescence quantification PCR (QRT-PCR) and
Semi-quantitative RT-PCR (SqRT-PCR), we analysis
the expression characteristics of
ARGAHs
genes
during seed germination, especially under NaCl
treatment, and aim to know about the function of
arginase genes responding to salt stress during seed
germination.
2 Results and Discussion
2.1 Homologous comparison analysis of
ARGAH1
and
ARGAH2
genes
There are two genes who encode arginase:
ARGAH1
,
ARGAH2
. Biological chemistry analysis shows that