An international team of scientists,
funded in the UK by the Biotechnology
and Biological Sciences Research Council (BBSRC), has
sequenced the genome of a Chinese cabbage variety of a plant
called Brassica rapa, a close relative of oilseed rape. The
research, which is published today (28 August 2011) in the
Genetics, could help improve the efficiency of oilseed
rape breeding, as well as that of a host of other important
food and oil crops.
The project was conducted by an international consortium
involving researchers working across four continents, with
the majority of the data generated in China. The UK's contribution
came from scientists at the John Innes Centre in Norwich
and Rothamsted Research in Hertfordshire, both of which
receive strategic funding from BBSRC.
Oilseed rape is an important source of vegetable oils for
cooking and industrial applications and its production has
doubled in the last 15 years. It is an unusual hybrid which
contains the entire genomes of two other plants: Brassica
rapa and another closely related species called Brassica
oleracea. By sequencing Brassica rapa, researchers are able
to access half of oilseed rape's genes without having to
wrestle with its large and complicated genome.
Professor Ian Bancroft led the research at the John Innes
Centre. He explains "Oilseed rape is the second most
important oil crop in the world and the most important in
Europe. Sequencing its genes will provide breeders with
the tools to improve the efficiency of developing new varieties,
but this is difficult because it has a really complicated
genome. Thankfully, because it is a hybrid, nature has already
divided up the oilseed rape genome into two more manageable
chunks, one of which we have now sequenced."
Brassica rapa and oilseed rape are both brassicas, a group
which also includes broccoli, turnip, sprouts and cabbages.
Together, this important group of plants accounts for more
than 10 percent of the world's vegetable and vegetable oil
production and, despite their apparent diversity, they are
all closely related. This enables scientists to apply the
insights they gain by sequencing one species, such as Brassica
rapa to improving the breeding efficiency of a range of
crops essential to ensuring global food security.
Professor Bancroft continues "Few people would confuse
a turnip with a cauliflower and yet, despite coming in a
range of shapes and sizes, brassicas are all very closely
related. This means that the many of the 41,000 genes which
we found in Brassica rapa will also be found in other brassicas
and the insights we gain from having this sequence could
be useful for improving everything from plants grown to
produce chainsaw oils to the sprouts on your Christmas dinner."
The Brassica rapa sequence was produced using a technology
which breaks the DNA into small segments before reassembling
the complete genome. Throughout its evolution Brassica rapa
has triplicated its genome meaning that the task of assembling
the final picture posed a particular challenge to the scientists
and the technology.
Professor Douglas Kell, Chief Executive of the Biotechnology
and Biological Sciences Research Council, said "Plants
have a tendency to multiply their genomes as they evolve.
This means that many important agricultural crops like wheat,
potato and oilseed rape have much larger and more complex
genomes than most animals, including humans.
"Helping breeders produce new varieties of these staple
crops will be essential to ensuring our future food security,
so scientists must use their ingenuity to find ways to overcome
the challenges posed by these massive genomes. This research
shows what can be achieved by applying the latest technology
and by combining the expertise of scientists across the