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Molecular Plant Breeding Provisional Publishing
Molecular Plant Breeding 2012, Vol.3, No.
6
, 57
-
62
http://mpb.sophiapublisher.com
57
Research Report Open Access
Expression of
E. coli
glg
B in Potatoes Generating Tuber Starches with
Various Features
Jinfeng Liu
1,2
, Xiujuan Feng
1
, Xueqiong Cui
1
, Qian Cai
1
, Xinling Yao
1
1. Life Science School, Ningxia University, Yinchuan, 750021, P.R. China;
2. National Key Lab of Seedline Bioengineering, Yinchuan, 750000, P.R. China
Corresponding authors email:
chinanoahl@163.com;
Authors
Molecular Plant Breeding, 2012, Vol.3, No.6 doi: 10.5376/mpb.2012.03.0006
Received: 18 Feb., 2012
Accepted: 03 May, 2012
Published: 04 May, 2012
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Preferred citation for this article:
Liu et al., 2012, Expression of
E. coli glg
B in Potatoes Generating Tuber Starches with Various Features, Molecular Plant Breeding, Vol.3, No.6 57
-
62 (doi:
10.5376/mpb.2012.03.0006)
Abstract
Expression of
glg
B in amylose-free mutant leads to accumulation of phytoglycogen of low molecular weight in potato
tuber. Performance of
glg
B expression in wild type potatoes is unknown at this point. In this study a
glg
B was isolated from
E. coli
JM 109 and it was expressed in two potato genotypes after function of
glg
B was confirmed. 18 transgenic lines were obtained by
PCR and Southern blot screening using
glg
B transformants. RT-PCR showed that
glg
B, driven by 35S promoter, was expressed at
different levels in 18 transgenic lines. Starch viscosity and amylose contents were assayed with tuber starches of the 18 lines. Data
analysis showed that although starch viscosity of all lines was significantly higher than that in the control, genotype of DXY
expressing
glg
B showed much higher starch viscosity than genotype of ZHB expressing
glg
B did. Meanwhile, amylose contents
were the same as those in the control and they were constant in all individuals with ZHB as host expressing
glg
B. However, all
individuals with DXY as host expressing
glg
B showed a higher amylose contents than those in the control. The results indicated that
starchgeneration altered along with different genotypes of transformed potatoes hosting gene. Expression of
glg
B led to a higher
starch viscosity of various extents.
Keywords
Potato;
glg
B; Starch; Expression; Genotype
Background
Genetic improvement on the endogenesis starch is
rapidly expanding the application of starch. Regulation
of downstream gene expression in the starch
biosynthesis pathway generated potato starch with
shorter chains and less amylose. Study on starches
modified by granule-bounded starch synthase (GBSSI)
found that the amylopectin cluster and the starch
granule remained the same as those in the control, but
the structure of the amylopectin cluster changed to
form starch with unique potential dynamic values in
application (Kozlov et al., 2007).
The potato expressed
E.coli glg
C increased tuber
starch accumulation through raising ADP-glucose
pryphosophrylase (AGPase) activity (Stark et al.,
1992). Inhibition of GBSSI expression led to reduction
in the amylose in the potato starch (Kuipers et al.,
1994), and starch branch enzyme (SBE) activities in
transgenic lines of which SBE A and B were
suppressed were less than 1% of those of the control.
Amylopectin with high molecular weight was no
longer synthesized, thus starch granule changed
morphologically, and phosphorus content in the starch
increased by 5 times. This starch is potentially
valuable for application (Schwall et al., 2000).
Starch branch enzyme and soluble starch synthase
(SSS) are closely related to the apparent amylose
content and taste quality in rice. SBE1 and SBE3
express specifically the genotype of high palatability
(Sun et al., 2011). SBEIIa is essential for transportation
of temporary-storage starch in maize leaves along
with the cycle of day and night (Yandeau-Nelson et al.,
2011). Activity of ADP-glucose pryphosophrylase in
the potato tuber changes with the day-night circle
(Tiessen et al., 2002). In addition, the other enzymes
involving in starch synthesis including SBE are