Basic HTML Version
Molecular Plant Breeding 2011, Vol.2, No.08, 48
-
59
http://mpb.sophiapublisher.com
48
Research Letter Open Access
Integration and Expression Stability of Transgenes in Hybriding Transmission
of Transgenic Rice Plants Produced by Particle Bombardment
Yan Zhao
1,2
, Longbiao Guo
2
, Huizhong Wang
3
, Danian Huang
2
1. College of Food Science and Biotechnology Engineering, Zhejiang Gongshang University, Hangzhou, 310035, P.R. China
2. State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006, P.R. China;
3. College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, 310018, P.R. China
Corresponding author email:
yanzhao9918@163.com;
Author
Molecular Plant Breeding, 2011, Vol.2 No.08 doi: 10.5376/mpb.2011.02.0008
Received: 26, Apr., 2011
Accepted: 14, Jun., 2011
Published: 20, Jun., 2011
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:
Zhao et al., 2011, Integration and Expression Stability of Transgenes in Hybriding Transmission of Transgenic Rice Plants Produced by Particle Bombardment,
Molecular Plant Breeding Vol.2 No.08 (doi: 10.5376/mpb.2011.02.0008)
Abstract
Four transgenic rice lines TR 5, TR 6, Ming B and Jingyin 119 obtained via particle bombardment were used as transgene
donors to create hybrids. The integration and expression stability of exotic bar and
cecropin B
gene in conventional hybriding
transmission were investigated by Southern and Northern blotting analyses. The selection marker bar gene was transferred to all
hybrids under selection of Basta herbicide. Loss or gain of small hybridization bands (no more than 2.0 kb) of bar gene occurred in
some hybrids, but the difference in integration sites of bar gene copies did not influence their stable expression. The non-selection
gene
cecropin B
was stably transferred from the four transgene donors to their resulting hybrids, but expression level was very
different. Silencing of
cecropin B
gene occurred in some hybrids from TR 5, TR 6 and Ming B. In the transgene donor Jingyin 119
and all its resulting hybrids,
cecropin B
and bar gene were stably expressed. We concluded that the stability of transgene during
crossbreeding transmission is mainly determined by the primary transgenic donors and may be affected by recombination.
Keywords
Transgene; Heredity and expression; Hybriding transmission; Particle bombardment; Rice
Background
Rice is the world’s most important food crop and a
primary source of food for more than half the world’s
population (Khush, 2005). Improvements in crop yield
have been achieved through conventional hybridization
and selection procedures (Peng et al., 2007). Currently,
rice hybrids are cultivated in about 55% of the
rice-growing areas in China and contribute to 66% of
the total rice production of the whole country (Wu and
Luo, 2007). The breakthrough in plant biotechnology
has provided tools to develop more elite transgenic
donors for crop crossbreeding. In the transformation
process, ideally, a single gene with its appropriate
controlling elements is added to the genome instead of
moving a whole chromosome or chromosome
segment with many known and unknown genes as
done with the traditional hybridizations (Horvath et al.,
2001). Since protocols for rice transformation have
been well established, genetic transformation is
currently complementing conventional breeding
programs in the development of advanced germplasm
(Popelka and Altpeter, 2003). In 1996, the herbicide-
resistant bar gene was transformed into Japonica rice
Jingyin 119 via particle bombardment (Huang et al.,
1996), and then the transgenic plants were
successfully crossed to the male-sterile line Pei-ai 64S
of a two-line crossbreeding system for creating
transgenic rice hybrids. Based on the herbicide
resistance of the marker gene bar, a new method was
created to examine and improve the purity of hybrid
rice (Huang et al., 1998). More recently, Chen et al.
introduced the synthetic
cryl2A*
and
crylC*
gene into
an elite Indica cytoplasm male-sterile restorer line
Minghui 63 and crossed the transgenic lines to
Zhenshan 97A to produce insect-resistant hybrid rice
(Chen et al., 2005; Tang and Lin, 2007). Transgenic
technology is providing new tools for the conventional
crossbreeding of rice.
The main methods used for rice transformation are
particle bombardment and
Agrobacterium
-mediated