Malaysia, UK to sequence genome of Hevea brasiliensis

ERJ staff report (DS)

Kuala Lumpur -- A joint Malaysian-UK research project is to investigate the full genetic sequence of the natural rubber tree -- Hevea brasiliensis. The aim is to permit the production of rubber trees having improved characteristics such as disease resistance, latex yield, girth and timber quality.

Longer term, however, the work would open the possibility to create trans-genic species in which a Hevea tree might be used for so-called molecular farming, when genetically modified plants are used as a cost-efficient sources for production of foreign substances important for pharmaceutical or industrial purposes. Therefore, there are proposals in discussion for this type of work. Previously, the Malaysian Rubber Board has mentioned the use of a modified H. brasiliensis to make human insulin.

The work will be carried out jointly at the Tun Abdul Razak Research Centre (TARRC) in Hertford, UK and the newly opened Genome Analysis Centre (TGAC) based at the Norwich Research Park, Norwich, UK. The project will utilise the extensive facilities at TGAC as well as those in TARRC's recently established Biotechnology Unit.

Initially the project will focus on a single H. brasiliensis clone from the RRIM 900 series. The MRB said "the potential high value of the information that would be provided by sequencing other Hevea species (such as H. guianensis, H. benthamiana, H. pauciflora, H. spruceana, H. microphylla, H. nitida) is appreciated and, therefore, number of proposals regarding sequencing of other Hevea species are currently discussed and could be materialised following the completion of current project."

The size of rubber genome (2000 million DNA base-pairs, or 2Gb) is one of the largest among cultivated species. For example, it is twice as big as oil palm genome, 5 times larger than those of cocoa and rice. It is about two-thirds the size of the than human genome (3Gb). The H. brasiliensis genome is a complex structure, with estimated at least 60% of it being repetitive sequences, making the sequence assembly task very challenging. It is projected that the sequencing phase using next generation technologies should be completed early 2010.