Agriculture Reference
In-Depth Information
genomics, transgenic technology and the
safety assessment of food/feed from GM
plants in China are reviewed below and in
Section 13.3 (see also Chapters 2 and 12).
bioinformatics database (Rice Mutant
Database, RMD) has been developed. At the
same time, full-length cDNA libraries of
some crops, such as rice, wheat and maize,
and research platforms of DNA microarrays
for rice and maize were built. In addition,
239 expression proi les of stress traits
including anti-adversity, disease resistance,
low phosphorus and low nitrogen were
developed; numerous key genes related to
dif erent stressors were identii ed (Chen
et
al
., 2006; NDRC/CSB, 2010; Qiu
et al
., 2011).
Many important genes in dif erent crops
have been cloned and studies of their
function and pathways performed. For
example, using map-based cloning and the
mutant library, genes underlying production,
quality and plant types in crop traits, such as
MONOCULM 1 (
MOC1
, a gene that is
important in the control of rice tillering),
Ghd7
(an important regulator of heading
date and yield potential in rice),
GS3
(a
major gene for grain length and weight),
GIF1
(a gene controlling rice grain-i lling
and yield) have been isolated and cloned (Li
et al
., 2003; Fan
et al
., 2006; Wang
et al
.,
2008; Xue
et al
., 2008); the genes underlying
disease resistance, anti-adversity and insect
resistance, such as
xa13
(a gene for bacterial
blight resistance in rice),
Xa26
(a gene
conferring resistance to
Xanthomonas oryzae
pv.
oryzae
in rice),
Bph14
(a gene conferring
resistance to brown planthopper in rice),
etc., have also been isolated and cloned (Sun
et al
., 2004; Chu
et al
., 2006; Du
et al
., 2009).
In addition, some genes in other crops have
also been cloned; for example, genes
underlying i bre cell elongation in cotton,
GhACT1
and
GmDET2
, and the development
of soybean,
TFL
, etc. (NDRC/CSB, 2010;
Tian
et al
., 2010; see also Chapter 2).
Functional genomics
In China, studies on molecular technology,
the construction of molecular linkage maps,
gene mapping, cloning and identii cation of
functional genes have achieved substantial
advances. Molecular linkage maps of
important plants, such as rice, wheat, maize,
soybean and cotton, have been constructed.
Quantitative trait loci (QTLs) underlying
the production, quality and resistance traits
of these plants have been mapped. More
than 1000 genes and QTLs in plants have
been mapped in the past two decades. In
excess of 500 gene loci have been i ne-
mapped (these loci explained more than
10% of the phenotypic variance and the
genetic distance from genetic markers of
less than 2 cM) with regard to traits
inl uencing production, disease and insect
resistance, anti-adversity, quality and
nutrient absorption ei ciency (Chen
et al
.,
2006; NDRC/CSB, 2010; Qiu
et al
., 2011).
h e i rst draft map of the rice genome
(
Oryza sativa
L. ssp.
indica
) was published in
October 2001 by Chinese scientists and the
i ne map was i nished in 2002. Subsequently,
the genome sequence and analysis of rice
(
Oryza sativa
L. subsp.
Japonica
var.
Nipponbare) chromosome 4 has been
i nished by the China National Center for
Gene Research. It is one of the two i rst-
sequenced chromosomes in the world. At
the same time, 80% of the genome sequence
and analysis of rice (
Guangluai-4
) chromo-
some 4 and the sequence analysis in the
centromere of chromosome 4 were also
i nished. h ereafter, the deep sequencing of
other plants such as wheat, cotton,
cucumber, tomato and watermelon has been
i nished or is in progress (Wan, 2011).
In China, many achievements have been
made in the construction of mutant libraries
in rice. h rough the use and reconstruction
of the enhancer trap system of GAL4/VP16-
UAS, a 2,700,000 strain T-DNA insertion
mutant library was obtained and the
Transgenic technology
Transgenic technology consists of gene
cloning and genetic transformation.
GENE
CLONING
TECHNIQUE
.
In recent years,
technology platforms for genome bio-
informatics, proteomics, biochip and geno-
typing have been developed and have laid
the foundation for large-scale gene cloning
