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Own goal

Own goal

作者:闻人候  时间:2019-03-07 05:02:06  人气:

By Andy Coghlan THE environmental protestors who vandalised a stand of genetically modified trees in Berkshire in the dead of the night on 11 July have been less successful than they hoped. Not only has their action helped improve the image of genetic engineering by drawing attention to an application intended to protect the environment, but the company involved says the trees should still produce enough wood to complete its experiment. Zeneca Plant Science grew the altered poplars at its Jealott’s Hill experimental station near Bracknell. The protesters tore strips of bark from some of the trees, planted in 1995, leaving them to wilt and die. Younger trees, planted in 1996, were cut and bent double. But the company is confident that the wood from the older trees can still be turned into paper as planned. “We’re not downhearted,” says Nigel Poole, head of regulatory affairs at Zeneca Plant Science. “The other nice thing is that total strangers phoned us up to suggest how we might save the trees. There’s been a lot of local anger about the incident.” The site contained 64 normal poplars as well as 88 genetically modified trees. “It was a small coppice, and they were all mixed up so you couldn’t tell which was which,” says Poole. The altered trees had been engineered to disrupt enzymes involved in the hardening of lignin, the polymer that reinforces plant cell walls and accounts for up to a third of the dry weight of woody plants. In papermaking, lignin has to be removed by treating wood pulp with a chlorine-based bleach. Zeneca hopes that paper made from its trees will need up to 15 per cent less bleach and save on energy—making the process kinder to the environment. In half the modified poplars, the gene for the enzyme cinnamyl alcohol dehydrogenase was neutralised. In the other half, a gene which makes the enzyme O-methyl transferase was silenced. “We’ve not altered the amount of lignin produced, simply its structure,” says Poole. “It’s a more open structure, so it’s easier to pull apart chemically.” The company harvested the dying trees earlier this week so that papermaking experiments can go ahead. In a statement released via the Genetic Engineering Network, an alliance of groups concerned about developments in biotechnology, the activists responsible for the damage argue that genetic modification of trees is “a major threat to the environment”. They claim that altered genes from Zeneca’s poplars could have spread to other trees. Poole contests these claims. He points out that the trees were all female and thus unable to produce pollen. Although they were too young to flower, he adds, any flowers would have been removed manually as soon as they appeared,