Agriculture Reference
In-Depth Information
attributed to the research over the last decade using
L. japonicus
and
M.
truncatula
.
Over the last year or two, the shift to
L. japonicus
and
M. truncatula
as the
model legume species has actually begun to shift again. This is largely due to
the emergence of the current genomic era. Recent advances now enable the
rapid identification of genomes and transcriptomes via next-generation
sequencing technologies (
e.g.
, the Applied Biosystems 454, the Illumina
Genome Analyzer and the SOLiD platforms). Thus, having a large genome is
no longer a constraint when it comes to investigating a species. Likewise, in
most cases using
L. japonicus
and
M. truncatula
strictly for their small
genome is no longer necessary. As a result, many researchers are shifting back
to using more economically significant legume species, including soybean
(Ferguson and Gresshoff 2009; Rispail
et al
. 2010).
Recently, the complete soybean genome has been sequenced and was
made freely available along with its associated annotated sequence
information (Schmutz
et al
. 2010; www.phytozome.net/soybean). As a result,
gene discovery in soybean is now more efficient and feasible than ever.
Furthermore, coupling the soybean genome with next-generation
transcriptomic data provides a powerful, high-throughput and non-targeted
tool for identifying novel genes and gene expression patterns.
Soybean also used to be undesirable for genetic research due to its
allotetraploid genome, a result of ancestral duplication events. However, this
too is no longer a constraint. Instead, by having multiple copies of genes,
soybean presents a unique opportunity to investigate evolutionary genomics,
including sequence divergence events and the functional redundancy of
gene/protein sequences.
Taken together with the near-complete genome sequences of
M.
truncatula
(http://www.medicago.org/genome) and
L. japonicus
(http://www.kazusa.or.jp/lotus), the soybean genome also provides an
excellent resource for comparative legume genomics (Cannon
et al
., 2009).
Other legume genomes, including those of bean, pea and the legume tree,
Pongamia pinnata
, are also likely to be made available soon, further
expanding the possibilities in the field of comparative genomics.
In addition to having its genome sequenced, soybean is one of the best
physiologically- and biochemically-characterised legume species. It is
amenable to most physiological and molecular studies. It also has a relatively
fast growth rate, is high yielding and has a user-friendly size and stature
making it ideal for use in most laboratory environments. Compared with much
smaller species, such as
M. truncatula
and
L. japonicus
, the relatively large
