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喜欢毒素的树

所属:听力板块 来源:普特英语听力 阅读:2669 次 评论:0 条 [我要评论]  [+我要收藏]

小编摘要:树木能调节气候,保持生态平衡,树木通过光合作用,吸进二氧化碳,吐出氧气,使空气清洁,新鲜。一亩树林放出的氧气够65人呼吸一辈子.

Toxin-loving Trees

 

In our increasingly complex age of high technology and instant electronic communication, it’s important to recall a few simple truths. Forexample–trees are good. Think about it trees help hold soil in place, create oxygen, and provide shade on hot summer days. And now, thanks to researchers at the University of Georgia, trees may soon help us clean up toxic waste.

Here’s how it works. Scientists isolated a gene from a type of bacteria that thrives in places polluted by mercury–a metal that is highly toxic in large amounts.

They then implanted the gene, which converts mercury into a less-toxic form, into day-old saplings. Once the genetically engineered trees were big enough, they were transplanted to soil contaminated by mercury. When tested against regular trees, the genetically enhanced trees were able to absorb and dilute ten times more mercury, which they released into the air as harmless vapor. In fact, the trees seemed to thrive on mercury. When grown in soil lacking the toxin, the trees became weak and sickly.

Mercury pollution is a serious threat to wildlife and to humans. Eating fish that have ingested large amounts of mercury, for example, can cause neurological damage in humans. Cleaning up soil and water polluted by mercury is typically very expensive, which makes mercury absorbing trees an even more attractive prospect. Trees are relatively cheap to grow and plant, and scientists hope to engineer trees to absorb other toxins besides mercury.

It remains to be seen how well the trees will function on a wider scale. But if they are able to help decontaminate our soil and water, we’ll have even more reason to appreciate toxin-loving trees. 

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2011-10-30 12:51 编辑:pliny
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