Plant frozen for 30,000 years revived
A plant frozen in Siberia for over 30,000 years has been brought back to life by scientists in Russia.
Writing in PNAS, Russian Academy of Sciences researcher Svetlana Yashina and her colleagues found seeds of the Silene stenophylla plant, a kind of campion, in ancient squirrel burrows under 38 metres of permafrost in northeastern Siberia.
Carbon dating of the seeds, which were part of an assemblage of more than half a million fruits, nuts and seeds sequested in the burrow, confirmed that they were 31,800 years old, give or take a few hundred years. Wedges of ice within the burrows also showed that the ground had remained solidly frozen at a steady-state -7°C throughout this time.
When the seeds were placed in a nutrient growth medium they showed signs of trying to germinate, albeit unsuccessfully. Encouraged by the apparent viability of the tissue, the team then explored the plant tissue connected to the seeds including a structure called the placenta, which links a parent plant to its developing seed. This was still in-situ around some of the recovered seeds and also showed signs of responding to warming and nutrients.
By culturing this placental tissue the researchers were able to trigger it to produce roots and shoots, and then new plants, which matured and produced flowers. Cross-pollinating these plants resulted in the formation of viable seeds from which further plants were grown.
Growing specimens of modern-day Silene stenophylla alongside their ancient relative revealed a number of subtle differences between the two, including the size and shapes of the flowers, with the ancient strain having narrower petals but more buds compared with the modern-day counterpart.
To resuscitate a species that hasn't grown on Earth for over 30,000 years is, by itself, an incredible achievement. But where the study is likely to prove particularly valuable is in informing strategies like the "Millennium Seedbank", which is a long-term storage initiative to safeguard seed specimens from plant specimens planet-wide. Knowing how to preserve seeds in a viable state, and perhaps re-kindle the life of the plant that made them, will be valuable information indeed.