Plants close to becoming miniature plastics factories: Genetic engineers believe oilseed rape could provide a rival to the petroleum industry. Susan Watts reports

GENETIC ENGINEERS are just months from solving the last few problems in a project to turn plants into miniature plastics factories.

An American researcher predicted yesterday that farmers could soon be planning livelihoods built on harvests of oilseed rape, growing valuable oils and industrial plastics. Chris Somerville said it would be an agricultural rival to the petroleum industry, which produces most of today's plastics from oil.

He was presenting his work at a meeting in London on the production and uses of genetically transformed plants. Professor Somerville, a botanist from Michigan State University, is one of a team that reported producing the first plastic in a weed called Arabidopsis thaliana, or thale cress, in the journal Science in April last year.

Since then, the team has carried out experimental work to test its production methods. 'That's where it gets a little bit funky,' he said. 'The tiny granules of plastic are accumulating in the nucleus of the plant's cells.' The scientists are baffled as to why this should happen. They are trying to persuade the plastic, poly-hydroxybutyrate, to gather in the parts of the plant where it would normally produce starch. Plastic gathering in the nucleus is a problem because it would eventually blast the plant's cells apart, Professor Somerville said.

He has already persuaded two of the three enzymes he needs for plastic production to be expressed in the right place in the plant, and believes that in the next few months he will get the third to appear there too. The team must also raise the level of plastic produced in the plants about 20- fold, 'to make something commercially interesting', Professor Somerville said.

'I am confident we are going to be able to solve the problems we face and that in the early part of the next century we will be producing this and other materials in crops,' he said.

Professor Somerville's plant-grown plastic should prove very cheap to produce. 'In genetic engineering terms it is relatively simple, since it is necessary to introduce only two extra genes into the plants.' The plastic they produce is easily biodegraded, he said, because of its biological source. It closest rival would be a biodegradable plastic, Biopol, under development. This is produced in bacteria with added genes. Professor Somerville said plants were up to a hundred times more efficient at producing plastic than bacteria.

Questioned on the possibility of cross-hybridisation of his 'plastics' crop with food crops in neighbouring fields, he said that eventually he envisaged plastics production in crops other than oilseed that might pose less of a threat - perhaps in the tubers of sugar beet. 'Birds wouldn't eat it, and beet is a very productive crop. Customers wouldn't have to encounter the crop because beet never ends up on the supermarket shelf.'

He said his plastic plants seemed to have been accepted by the public. 'They see this as addressing a social goal in that it produces a biodegradable material from a renewable source, and takes us away from the profligate use of petroleum.' He said this could be the beginning of a trend in public acceptance of the benefits of gene technology in agriculture.