Tree trials to check on gene 'leakage'

Scientists at the Forest Research Institute plan to use their two field trials with genetically engineered pine trees to check whether altered genetic material is "leaking" into the environment.

Forest Research received approval in December 2000 for field trials with trees engineered for resistance to the herbicides Buster and Escort, and to modify reproductive processes to affect wood growth.

The applications were not affected by the Government's moratorium on field trials, but the researchers voluntarily delayed their field trials until the end of the Royal Commission on Genetic Modification, and 1000 trees have been held in greenhouses. The moratorium was lifted last October, at the same time as the Government banned commercial release of GM organisms for two years.

The Forest Research scientist in charge of its biotechnology team, Dr Christian Walter, said his team now planned to use the field trials to investigate whether there was a transfer of genes from GM pines to any other organisms. The royal commission had canvassed the potential for the use of genetically engineered plants and animals outside contained areas such as laboratories or greenhouses to risk "horizontal gene transfer".

One pathway for this could involve the movement of altered DNA from an engineered plant or animal to soil organisms, and from them to other plants or animals outside the test zone.

But so little was known about the extent to which this natural process might happen, or present an environmental or health risk, that the commissioners themselves called for greater investment in research into horizontal gene transfer.

"There are some significant gaps in knowledge on which to base risk assessments for field trials or release of genetically modified organisms," the commission said in its report.

In relation to the potential risk of horizontal gene transfer from modified tree roots to soil microflora with impacts on soil ecology, one of its key recommendations was that in any proposal to develop GM trees an ecological assessment be required to determine the effect on soil and environmental ecology, including soil micro-organisms.

Walter said a lot of research had been done overseas on horizontal gene transfer, and this could be used as a basis for the New Zealand work.

Some of the questions to be investigated would include any differences between genetic codes which were previously in the GM trees, and those which had been added to them, in terms of the rate at which they migrated to the wider environment,

Some people feared that the novel genes would transfer to the wider environment at a faster rate than the conventional genes in the plants.

Previous researchers who had examined horizontal gene transfer had either not found it, or found it happened very infrequently.

He said Forest Research had avoided partnerships with commercial foresters on this publicly funded project so that it would be free to publish the result of its work, regardless of whether it was seen as beneficial or bad news by the industry. The field trials - with a number of other experiments - were planned for 20 years, but an initial research programme should start giving some answers within five years.

Another important line of inquiry would be identification of the ways particular genes were expressed.

And by identifying which gene sequences were linked to specific traits, such as stronger fibre, or faster growth, foresters would be able to take advantage of this knowledge without using GM trees.

"Reading" the genetic sequences in particular breeding lines would indicate which conventional seedlings could be grown for specific traits.

The royal commission said in its final report to the Government that it had heard "considerable public doubt" about the adequacy of the containment of a field trial of transgenic tamarillos.

Walter said he hoped people critical of the potential for "leakage" of novel genes would take an interest in the experiments.

- NZPA

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Report of the Royal Commission on Genetic Modification

GE lessons from Britain

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