|
Russian scientists say they've grown a flowering plant from material extracted from seeds deposited in the Siberian permafrost 30,000 years ago. The work of the scientists at the Institute of Cell Biophysics in Russia is creating a worldwide buzz after being published in Proceedings of the National Academy of Sciences in the United States. Previously, the oldest known seed material that has been able to produce life was from about 2,000 years ago, science writer Ed Yong reports in a Discover magazine blog giving details of the work of the Russian breakthrough. The plants, named silene stenophylla, are from a time when wooly mammoths and saber-tooth cats lived in Siberia. Their 300-century path to life began when squirrels brought the fruit of the plant and the immature seeds the fruit contained into a riverbank burrow. As the climate cooled, the burrow was covered with layers of ice and the seeds were preserved by temperatures of minus-7 degrees Celsius (19.4 degrees Fahrenheit), according to Yong's report. The immature seeds were extracted from the burrow along the banks of the Kolyma River more than five years ago. The Russian scientists were able to take what is called "placenta tissue" from the immature seeds, grow that tissue into mature seeds in a lab environment, and then plant those seeds in normal soil and watch them grow into the blossoming plants, according to a report from the Russian news agency RIA Novosti. Those plants have now produced their own seeds and fruits, establishing a whole new generation of the ancient plant, the reports said. The ancient plants differ only slightly from their modern descendants in the shape of their petals and sex of the flowers, the RIA Novosti report said. The news of the ancient plants brought to life immediately brought speculation about whether other life forms might be resurrected from the permafrost, which James Haile, a scientist at Murdoch University in Australia, said earlier this year was "a giant molecular freezer" preserving the DNA of a thriving Pleistocene ecosystem. "Siberia, Alaska and the Yukon could act as one massive freezer, where ancient life has been stored, waiting to greet the world again," Yong wrote on his blog. "The success of the Russian scientists may open a door to a whole new area of experiments in reviving extinct plants buried under layers of soil, especially in the Arctic zone, for thousands of years," the RIA Novosti article said. The new findings may give hope to a team of Russian, Japanese and American scientists who reported a year ago that within six years they hope to produce baby mammoth from DNA extracted from a Pleistocene mammoth carcass.
俄科学家成功让3万年前种子复活 （2012-02-22） 在莫斯科附近的实验室里，科学家们试图用成熟的果实进行种植，但是失败了。他们转而采用植物的胎盘组织，结果在控制温度和光照的条件下，成功地在花盆里培植出了全株植物。
史前奇芭: 这就是俄罗斯科学家成功 用3万1800年前的种子种出来的史前剪秋罗属植物。它和现代同类植物相似，但叶子较宽。（美联社）
（华盛顿法新电）俄罗斯科学家成功地用3万年前的果实种子培育出植物，还开了花。这是科学家首次让这么古老的植物再生。
研究团队领导人、俄罗斯科学院的亚希纳和吉利辛斯基说，这无疑是第一次让这么古老的植物复活。在这项纪录之前，科学家曾将一颗在以色列靠近死海的地方发现的2000年棕榈科种子种活。 这颗属于剪秋罗属植物（Silene stenophylla）。研究员对这颗种子的生物组织进行放射性碳测定年代分析后，已确认为它已存在了3万1800年，可能偏差为300年。 周二出版的《美国国家科学院学报》上发表的这个研究报告说，俄罗斯考古学家在西伯利亚科雷马河岸边的永冻层中，发现了70个松鼠冬眠的洞穴，里面有很多各种植物的果实。 报告还说：“所有洞穴都离地表20-40米，土层里还有大型哺乳动物如猛犸象、披毛犀、野牛、马、鹿和其他的晚更新世时期动物的骨头。” 冻土层实际上有如一个巨大的冰箱，松鼠收藏的种子和果实在这个封闭世界里一直处于平均零下7摄氏度的环境中，数万年来从没有融解过。 在莫斯科附近的实验室里，科学家用成熟的种子进行种植，但是失败了。他们于是转从这些果实的胎盘(植物生出种子的部分)中提取出细胞，然后培育出新的种子。 结果，在温度和光照受控制的条件下，这些种子成功地在花盆里培植出了全株植物。 这种剪秋罗属植物目前在西伯利亚冻原上还有，这株史前剪秋罗属植物的外观与现代同类植物非常相似，但叶子较宽。加拿大育空地区育空古生物学计划的扎祖拉告诉记者：“这是神奇的突破。我毫不怀疑这个成果的合法性。” 科学家早已经知道，某些植物的细胞在条件合适的情况下可以存活上千年，比如北美野生宿根植物北极羽扇豆（Arctic Lupine）。20世纪中期，育空区的金矿工人在一个1万年前松鼠洞穴中发现的植物种子，就发芽生长了。 俄罗斯科学家的成果，可能成为古代生物材料学研究的里程碑，同样的技术也可能为人类让其他物种包括已经灭绝的生物再生带来希望。 研究报告还指出，这项成果也在在表明，冻土对于搜索曾经在地球上出现过的古老生命的重要性。 |
|
|
来自： darry > 《News Reposted》
