Basic HTML Version
Legume Genomics and Genetics (online), 2011, Vol. 2, No.1, 1-5
http://lgg.sophiapublisher.com
Figure 5 78 kD (SBP) isotypes of roots of 72 hours germinated
pea seeds
Note: The pI values are: 5.75, 5.82, 5.87, 5.95, 6.00, 6.27 and
6.67
5.66, 5.82, 5.88, 5.91 and 6.55. Partially separated
isotypes in dry pea seeds having a pI value 5.92, 5.94,
5.96 and 5.98 (Figure 1). Embryos of forty hours
germinated pea seeds have nine isoytpes with pI 5.76,
5.84, 5.89, 5.94, 6.16, 6.30, 6.42, 6.52 and 6.64. The
one with pI value 6.30 is the most prominent and
having two spots with slight different molecular
weights, the most lower spots almost separated from
the upper one (Figure 2). Data presented in figure 3
showed stems parts of 72 hours germinated pea seeds
that contain the highest expressed isotypes than other
investigated parts. Stem contains eleven isotypes of 87
kD (SBP) with pI
values 5.60, 5.88, 5.97, 6.05, 6.13,
6.18, 6.27, 6.30, 6, 39, 6.51 and 6.65. The isotype with
P
I
6.3 was most abundant and distinguished into three
spots with slight different molecular weight and the
isotypes with pI 6.39 next most abundant and
distinguished into two spots with different molecular
weight. Plumules of 72 hours germinated pea seeds
have two distinguished unseparated parts of isotypes
(Figure 4). The isotypes part with a pI value ranged
from 5.78~6.08 having six isotypes with pI values
5.78, 5.87, 5.90, 5.98, 6.02 and 6.08. And the other
basic part with P
I
value ranged from 6.30~6.46 having
four isotypes with pI values 6.30, 6.40, 6.42, and 6.46.
The isoelectric points of 87 kD (SBP) isotypes in pea
roots of 72 hours after germination were located in a
range of pI between 5.75 and 6.67 (Figure 5). It
contains two parts of isotypes, the acidic one have
three isotypes with pI value 5.75, 5.82, and 5.95, and
the basic isotypes almost unseparated with pI value
varied from 6.27~6.68. The basic part distinguished
into three overlapped isotypes and the lower mo-
lecular weight spots almost separated from other spot.
The data presented here show changes in isotypes
pattern of 78 kD (SBP) in dry seed, and during ger-
mination and in different parts of pea embryos indi-
cating that post-translational modification was involved
or may be caused by progressive phosphorrylation
during seeds dormancy and during germination.
Since investigating the biochemical properties of 49 kD
apyrase isotype obtained from cytoskeleton fraction of
germinating pea seeds, found that there were five
isotypes with different isoelectric point (5.82, 6.05,
6.30, 6.55, and 6.80), that may be due to post-trans-
lational modification (Abe et al., 2002). And another
study indicated that formation of similar isotypes
caused by progressive phosphorylation with increasing
acidity and increasing apparent molecular mass
(Duncan and Song, 1999). What might various roles
of 87 kD (SBP) isotype be? There is evidence sug-
gesting that biotin and biotin-containing proteins
might play specialized roles in regulation of plant
development. Thus biotinylated enzymes are required
for both growth of vegetative tissues and synthesis of
storage lipids in developing seeds (Stumpf, 1980;
Harwood, 1988). It is possible that various proteins
isotypes function is not merely to hydrolyze nucleoside
phosphates, instead they may be involved in some
other action, such as mRNA transport along the
cytoskeleton (Davies et al., 2001). Changes in tubulin
isotypes in rye roots induced by low temperature
revealed that the cold stability of microtubules is altered
by growth temperature and this cold stability may be
related to freezing tolerance (Kerr and Carter, 1990).
Additionally, changes in tubulin isotypes in rye roots
were noted after only 2 d and 4 d at 4 , and pronounced
℃
changes in the α-tubulins occurred in case β-tubulin
isotypes were affected by low temperature (Gregory
and John, 1990).
The polymorphism of aldehyde oxidase isoforms
observed in both leaves and roots of pea seedlings that
changed during plant vegetative development and the
activity and protein level of each isoform is regulated
not only by environmental conditions but also through
plant developmental stages (Zdunek-Zastocka et al.,
3