• Reduce text
  • Restore text size
  • Increase the text
  • Print

Sequencing of the genome of Chinese cabbage

An international consortium of scientists (including a team from INRA) coordinated by the Chinese Beijing Genome Institute (BGI), the largest sequencing centre in the world, has announced sequencing of the genome of Chinese cabbage (Brassica rapa). In France, this research forms part of a more ambitious sequencing project, led by INRA, on the genome of rapeseed (Brassica napus), the leading species cultivated for its oil in Europe. Anticipated in 2012, sequencing of the rapeseed genome will open the way to obtaining varieties that are more resistant to diseases, parasites and climatic variables, and with a higher oil content.

Colza hybride Synergy (coobtention INRA SERASEM).. © INRA, WEBER Jean
Updated on 05/19/2015
Published on 10/18/2011

Although they are morphologically very different, species such as rapeseed, cabbage, turnip rape (Chinese cabbage), broccoli, cauliflower or mustard are very similar genetically and belong to the same genus of Brassica. Together, these different species produce more than 12% of plant oils and more than 10% of legumes throughout the world. The cultivation of rapeseed ranks second in the world after that of soybean, and is the leading European species grown for its oil; production has almost doubled during the past 15 years. Rapeseed is also an important source of protein for animal feed.

Since 2009, INRA has been implementing a sequencing programme on the whole gene of winter rapeseed, funded by the French National Research Agency (ANR). This project, coordinated by an INRA team in the Joint Research Unit for Plant Genomics (URGV), associates INRA teams from Rennes and Evry and the CEA (1), and is being carried out in collaboration with international scientists and rapeseed breeders from the private sector.
Because of a polyploidisation event that is common in the plant world, rapeseed contains two complete genomes arising from its two parental species: Chinese cabbage and Mediterranean cabbage (Brassica oleracea). The latter covers a group made up of numerous sub-species (broccoli, cauliflower, Romanesco, etc.). Because of its double genome, rapeseed possesses about 80,000 genes. Thanks to its participation in the sequencing of Chinese cabbage, the French team now has access to all of its 41,000 genes, or about half that of rapeseed.
As it has only been cultivated for a relatively short time, there is considerable potential for the improvement of rapeseed. Deciphering its genome will provide plant breeders with tools to improve the cultivation of this species and enable the development of new varieties. In addition to factors concerning resistance to disease or climatic variables, etc., an increase in the oil content and higher yields are also paths for potential improvements.
By sequencing the rapeseed genome, INRA researchers are also contributing to study of a model that will help to clarify recurrent polyploidism in plants and the consequences of this important mechanism in terms of their evolution.

(1) Joint Research Unit for Plant Breeding and Biotechnologies, INRA Research Unit for the Study of Plant Genome Polymorphism, CEA-Génoscope.

REFERENCE

Xiaowu Wang, Hanzhong Wang, Jun Wang, Rifei Sun, Jian Wu, et al. The genome of the mesopolyploid crop species Brassica rapa. Nature Genetics, 28 août 2011. doi:10.1038/ng.919