In 2012, a team of Russian scientists led by the biologist Svetlana Yashina achieved a milestone for botany —and science, in general— that has so far not been surpassed: reviving a 32,000-year-old plant from seeds that they remained frozen in the permafrost of Siberia, in Russia. Silene stenophylla, the regenerated plant species, also existed in the last ice age, during the Pleistocene, when woolly mammoths roamed the Earth and glaciers extended beyond the polar ice caps to near the tropics.
Frozen seeds for around 32,000 years
The seeds of the species S. stenophylla were found by chance, as the scientists who found them were studying ancient squirrel burrows 38 meters below the surface in an area near the Kolyma River (northeastern Siberia). At that depth, the plant remains had remained frozen at a temperature of -7°C, along with small remains of mammoth, bison and woolly rhinoceros bones.
Although this plant still flourishes today, Yashina and her colleagues at the Institute of Cellular Biophysics of the Russian Academy of Sciences in Puschino wanted to germinate the seeds they found to find out if the ancient plant was similar to modern ones. However, there was a problem: none of the mature seeds had successfully germinated in the ground.
For that reason, they intervened in another way: they extracted placental tissues from the immature seeds and began to cultivate them in vitro in vials. Only in this way did they manage to get the first samples, the scientists indicated in the article in which they described their feat, published in the Proceedings of the National Academy of Sciences.
Although in the early stages of germination the archaic plants were similar to their contemporary counterparts; when they finally bloomed, they began to distinguish themselves by having longer and more separated petals. Also, the seeds they generated grew better than current plants, so they were much more fertile.
The oldest plant ever revived
With this experiment, S. stenophylla became the oldest plant ever regenerated. The feat surpasses the resurrection of the date palm —also known as the Methuselah tree— a species of plant that dates back to the 11th century BC.
The scientists theorize that the success of the experiment could be due in part to the high sucrose content that the plant cells preserved, as well as the low level of radiation that did not ruin the plant’s DNA. The resurrection of biological species is not restricted to plants. Currently, various scientists seek to resurrect extinct animals such as the Tasmanian tiger.