Scientists have grown a flowering plant from fruit tissue that spent roughly 32,000 years frozen in Siberia, a record for the oldest plant ever brought back to life. The story starts with an unlikely helper: an Ice Age ground squirrel that stored seeds for the winter. Here is what the researchers did, and what the result does and doesn’t mean.
A Squirrel’s Pantry Frozen in Time
The plant is Silene stenophylla, a small flowering plant that still grows in northeastern Siberia today. A team of scientists from Russia, Hungary and the United States found its frozen fruits and seeds while investigating about 70 ancient ground squirrel burrows and food caches buried in permanently frozen deposits of loess and ice.
Rodents normally eat what they store, but in this case a flood or some other weather event appears to have buried the area. Because the squirrels had dug their larders down to the level of the permafrost, the contents froze almost immediately and, according to the researchers, never thawed afterward. More than 600,000 fruits and seeds were preserved at the site.
Radiocarbon dating placed the material between 20,000 and 40,000 years old, in the Pleistocene epoch, and the fruit used in the revival was dated at about 32,000 years.
How the Plant Was Brought Back
A team at the Russian Academy of Sciences, led by David Gilichinsky, used material from that expedition. Their first idea was simple: germinate the mature seeds. It didn’t work.
So they turned to the fruit itself. They took tissue from the placenta, the part of the fruit that holds the seeds, and cultured it in the lab. From that tissue they grew 36 plants, and the plants went on to flower and produce seeds of their own.
The previous record for reviving ancient plant material was about 2,000 years, set with Judean date palm seeds, so this result beat it by roughly 30,000 years.
How the Revived Plants Differed
The regenerated plants looked identical to modern Silene stenophylla until they flowered. Then the researchers noticed that the petals were longer and more widely spaced than in modern plants. The seeds they produced also germinated at a 100% rate, compared with about 90% for modern plants. Scientists don’t yet know why these differences appear.
Why Did the Tissue Survive?
The researchers offered a few ideas. One is that the tissue was rich in sucrose, a sugar that may have acted as a natural preservative. Another is that the DNA damage caused by natural background radiation at the site was unusually low for material so old, comparable to levels seen in lotus seeds around 1,300 years old that are known to germinate.
Robin Probert of the Millennium Seed Bank called it by far the most extraordinary example of extreme longevity in higher plants. Paleontologist Grant Zazula, who has previously challenged claims of ancient regeneration, said the discovery raises the bar for what scientists think is possible for ancient life in permafrost.
What This Doesn’t Mean
It’s easy to get carried away, so here are some important limits:
- The plants were grown from preserved fruit tissue in a laboratory, not from a seed that simply sprouted. They are clones of the original tissue.
- This is one species in one set of very unusual conditions. It does not mean that any ancient seed can be revived.
- Probert hopes the techniques could someday help bring back extinct species, but that is a hope, not a plan, and nobody is close to doing it.
- The researchers admit they don’t fully understand why the tissue survived or why the new plants look slightly different.
Permafrost, Climate and Hidden Life
Permafrost is ground that stays frozen year-round, and parts of the Arctic are warming and thawing. Frozen layers can hold well-preserved plants, animals and microbes from tens of thousands of years ago, which makes them valuable to scientists. Researchers also study what happens when they thaw, since a lot of material locked away for ages could be exposed. As Zazula’s comment suggests, we don’t yet know everything the permafrost contains.
Support Science and Seed Conservation
If this story fascinates you, here are some ways to get involved:
- Support seed conservation. Compare seed bank donations, plant conservation charities and botanical garden memberships.
- Learn more. Look into online science courses, science museum tickets and natural history documentaries.
- Try growing something. Browse seed starting kits, grow lights and home gardening kits.
- Explore the Arctic responsibly. Compare Arctic wildlife tours and eco-friendly travel packages, and consider travel insurance for remote trips.
- Get hands-on. Microscopes and educational science kits are great for curious kids and adults.
Frequently Asked Questions
What plant was revived? Silene stenophylla, a small flowering plant that still grows in northeastern Siberia.
How old was it? The fruit it was grown from was dated at about 32,000 years old.
Was it a seed that sprouted? No. The seeds didn’t germinate, so scientists grew plants from tissue taken from the fruit.
Who stored the seeds? Ancient ground squirrels, which buried them in burrows that were later frozen into permafrost.
Could scientists revive extinct species this way? One researcher hopes the techniques might help one day, but this is far from certain.
Sources: A study published in the Proceedings of the National Academy of Sciences by S. Yashina and colleagues, with comments from Robin Probert of the Millennium Seed Bank and paleontologist Grant Zazula, all covering the revival of Silene stenophylla from frozen Siberian fruit tissue.