Tobacco solves oil crisis

Biotechnology breakthroughs: starch and evening primrose oil yields and the use of holograms

Sunflowers or oilseed rape could prove a richer source of evening primrose oil than evening primrose itself, thanks to innovative research at the Institute of Arable Crop Research.

Using a novel technique, Olga Sayanova, based at IACR's Long Ashton Research Station near Bristol, has isolated the gene responsible for making gamma-linolenic acid, a fatty acid which is the characteristic component of the evening primrose's highly prized oil.

The chemical is believed to relieve diabetes, eczema, PMT and even some types of cancer. But the human body cannot always make enough of the chemical, and this is when the oil from either evening primrose or starflower can help.

Dr Sayanova noticed that enzymes which synthesise other fatty acids in plants contain a unique pattern of amino acids, the building blocks of proteins. She picked out the gene responsible for gamma-linolenic acid synthesis from starflower, using a "DNA library" - a kind of "soup" of all the starflower's DNA fragments.

She has now engineered the new gene into the tobacco plant, an oil-producing plant which can be readily manipulated by genetic engineering, to show that the gene is capable of producing the gamma-linolenic acid in other plants also.

Gamma-linolenic acid normally occurs only in a small number of plants, including evening primrose, starflower and some types of berry. But the seeds of these plants, which is where the oil is found, are very small. This means that extraction of the oil is difficult and yields are low.

Scientists at Long Ashton hope that by introducing the gene into plants with larger seeds, such as sunflower or oilseed rape, higher yields of the oil will be possible.

Peter Shewry, director of IACR Long Ashton, says the advance could boost the yield from a commercial oil crop by up to ten times that possible from just evening primrose, paving the way for large- scale pharmaceutical use.

"It could also have wider implications for the production of other pharmaceutical oils in crops. In the long term it may, for instance, be possible to produce fish oil in crop plants," he said.