Triticeae Genomics and Genetics 2015, Vol.6, No.2, 1-7
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breeding efficiency and genetic gains. Hence over the
past 30 years, molecular marker and biochemical
technologies have been developed and applied to plant
breeding, enabling breeders to use the genetic
composition or genotypes of plants as a criterion for
selection and breeding process. Currently, the genetic
diversity of plant has been assessed more efficiently
after the introduction of methods that reveals
polymorphism directly at biochemical and molecular
level. So the study of polymorphism is best done at
the level of DNA and protein, the primary source of
all biological information. Numbers of efforts also
have made to characterize genetic diversity in wheat
with biochemical markers. Comparison of "protein
profiles" obtained from tissues under different
conditions can indicate quantitative changes at protein
level and unique proteins are potentially useful in
ultimately understanding the cellular events that are
occurring at that time. Similarly, a comparison of
protein profiles from unstressed and stressed
organisms could lead to the identification of proteins
associated directly or indirectly with the stress
response. The protein profiling of germplasm and use
of genetic markers have been widely and effectively
used to determine the taxonomic and evolutionary
aspects of several crops (Murphy et al., 1990; Das and
Mukarjee, 1995; Ghafoor et al., 2002).
Two types of subunits are present in wheat protein;
the low molecular weight (10,000~70,000 Da) and
the high molecular weight glutenin subunits
(80,000~130,000 Da) (Bietz and Wall, 1972). Studies
on the genetic determinism of wheat glutenin have
revealed that HMW-GS genes are located on the long
arm of chromosomes 1A, 1B, and 1D at loci Glu-A1,
Glu-B1, and Glu-D1, respectively. And each Glu-1
locus consists of two tightly linked genes, which code
for x- and y-type subunits (Payne, 1987). In hexaploid
wheat, the Glu-A1 locus codes for 1Ax or null (N)
subunit, whereas the Glu-B1 locus usually codes for
1Bx and 1By. Sometimes, Glu-B1 codes for 1Bx or
1By subunits only; and the Glu-D1 locus codes for
1Dx and 1Dy subunits. Thus, for hexaploid wheat,
each genotype usually produces three to five
HMW-GS (Payne and others, 1984b; 1987).
Electrophoretic studies have revealed appreciable
polymorphism in the number and mobility of
HMW-GS in both bread wheat (Lawrence and
Shepherd, 1980; Payne et al., 1980) and pasta wheat
(Branlard et al., 1989). The Low Molecular
Weight-Glutenin Subunits (LMW-GS) represents
about one-third of the total seed protein and 60% of
total gluten protein (Bietz and Wall, 1973).
A large number of germplasm lines can be
characterized for biochemical markers in a short
period of time. In addition, the data reflects more truly
the genetic variability as biochemical markers are
direct product of genes expression (Perry and
McIntosh, 1991; Masood et al., 2000). Among
biochemical techniques, SDS-PAGE is widely used
due to its simplicity and effectiveness for describing
the genetic structure of crop germplasm (Murphy et al.,
1990; Javid et al., 2004; Anwar et al., 2003.). The
analysis of storage protein variation in wheat has
proved to be a useful tool not only for diversity
studies but also to optimize variation in germplasm
collections (Ciaffi et al., 1993; Masood et al., 2000).
1 Materials and Method
1.1 Plant materials
A set of twelve prominent wheat genotypes included 6
salt tolerant (KRL-1-4, KRL-19, Kharchia-65,
KRL-210 KRL-213 and Raj-3765) and 6 salt
susceptible (MP-4010, HD-2932, Lok-1, HI-8713,
C-306 and Raj-4037), had been provided by All India
Coordinated Research Project (AICRP) from
Department of Agronomy, Rajasthan College of
Agriculture, MPUAT, Udaipur, Rajasthan (India).
(Table 1).
1.2 Extraction of water soluble protein, dialysis,
lyophilization and SDS-PAGE
After procurement of seeds all the experiment is
conducted at Department of Molecular Biology and
Biotechnology, Rajasthan College of Agriculture
during March, 2012. The seeds were sterilized with
0.1% mercuric chloride solution for 2 min and used
for protein extraction. Seed were homogenized in
glass pestle and mortar with phosphate buffer (0.2 M,
and pH 7.4). The homogenate was centrifuged at 5000
rpm for 15 min. The supernatant obtained was
dialyzed, lyophilized and used for protein profiling
(Seth and Khandelwal, 2008). Qualitative test for
presence of protein was performed at every step.
Dialysis was carried out in semi permeable dialyzing
tubes (15 cm×2.5 cm). The dissolved precipitate was
dialyzed against distilled water. The dialysis was carried
