Seeds can be found everywhere in our daily lives, from peanuts to coffee beans. But seeds are not just a delicacy on our table, in botany, they represent the beginning of life.
A seed envelops the hope of the future: the seed coat protects it, the embryo is the origin of life, and the endosperm is full of nutrients. But do you know how strong the vitality of a seed is? How long can it survive? However, until reading this article, no one should dare to believe that the current record for the longest survival of a seed is 32,000 years!
Various seeds Image source: Author AI generated
Seeds from 32,000 years ago in the permafrost have been resurrected
Imagine that in the animated film "Ice Age", the nut-seeking squirrel may never have imagined that the seeds buried by its ancient counterpart would become a scientific miracle 32,000 years later.
In 2007, Russian paleontologists discovered a series of nests of ancient squirrels deep in the permafrost of the Kolyma River in Siberia. Buried 20 to 40 meters underground, these caves serve as a time capsule and contain a batch of plant seeds that are about 32,000 years old.
By 2012, scientists had launched an unprecedented attempt: to resurrect these ancient seeds. Their success in cultivating Silene stenophylla was not only a breakthrough in botanical history, but also a new record for the resurrection of the oldest plant seed.
But this resurrection process is not a simple planting, but a technical challenge. Scientists first extracted embryonic tissue from these ancient seeds, and then used sophisticated tissue culture techniques to achieve this restart of life.
So why have these 32,000-year-old seeds survived to this day? Researchers speculate that the seeds were buried by squirrels and then frozen in permafrost, which has not thawed since. This frozen environment provides a unique preservation condition for the seeds, allowing them to travel through time.
When these 32,000-year-old plant seeds were discovered and resurrected by a team of expert scientists, they not only showed the remnants of the past, but also provided us with a unique opportunity to study ancient creatures. Nurtured, these ancient narrow-leaved flies produce flowers that, although slightly different from their modern counterparts in terms of petal gaps, length, and leaf morphology, remain intrinsic and serve as a biological bridge between the past and the present.
32,000-year-old seed from the narrow-leaved fly grass Image source: Reference 1
A miracle of two thousand years of seeds in the rubble of the castle
Before the seeds of the Sycophyllum angustifolia broke the record for the resurrection of ancient seeds, there was a story already circulating in the scientific community: the resurrection of the seeds of the date palm tree 2,000 years ago. The story begins in the Arava Desert in southern Israel, a place that was once home to date palm palms.
These trees have been disappearing for hundreds of years due to climate change and lack of water. However, 40 years ago, while excavating the fortress of Machada, an ancient castle on the eastern shore of the Dead Sea, archaeologists discovered a batch of date pits that brought the long-lost date palm back to life in modern times.
Scientists have conducted a series of meticulous experiments with these ancient jujube pits. They put the date pits in a thermos flask, slowly watered them, and used gibberellic acid and plant growth hormone to promote their germination and rooting. Subsequently, these seeds are planted in pots filled with fresh soil.
After 26 months of careful cultivation, these 2,000-year-old date palm seeds not only germinated, but also grew to a height of 121 centimeters. This resurrection is made possible in the extremely dry and hot climatic conditions of the Dead Sea region, which provide an almost perfect natural environment for the seeds to preserve.
Through DNA analysis of these ancient date palm leaves, scientists have found that although these ancient varieties are more than 50% similar at the genetic level to modern date palms, they still retain a unique historical imprint.
The most surprising thing is that with unremitting efforts, these ancient trees even bear fruit. The first harvested dates weighed an average of about 18 grams each, which was described as extremely tasty. This scientific research is not only a triumph of science, but also a beautiful story of time and vitality. Although we have not yet been able to witness the resurrection of the dinosaurs, we can already taste dates thousands of years ago, and this is the beauty of scientific research.
Figure 32 A date palm tree that grew from seeds thousands of years ago. Image source: Ref. 2
In order to determine the seed lifespan
Scientists did an experiment that lasted for a hundred years
On a quiet early morning morning in April 2021, a hidden corner of Michigan State University became a gathering place for a group of botanists. Armed with searchlights and shovels and tape measures, they followed an old map and began an unusual excavation.
Their goal is not a treasure in the traditional sense, but a batch of seeds that have been buried for 142 years, and these are just some ordinary weed seeds. But they are part of a great scientific experiment that lasted more than a century. However, it is a very long and great scientific experiment, which has been going on for more than 140 years and will have to wait another 80 years to complete.
Figure 4 Schematic diagram of seed mining Image source: Author AI generated
This experiment, designed by Professor William James Beale in 1879, was designed to explore the actual lifespan of dormant seeds. Professor Bill prepared 20 glass bottles, each containing 1,050 seeds from 21 different plant species, 50 each, mixed with moist sand and buried on campus.
Initially, it was planned to dig up a bottle every 5 years to test the survival of the seeds. However, over time, this time interval has gradually lengthened, from 20 years in the 20s to 80 years in the 20s.
After more than a century of long waiting, most of these seeds have lost their vitality, but amazingly, the seeds of Verbascum blataria still remain alive. This discovery not only validates the amazing vitality of seeds, but also provides us with valuable data on seed survival and ecosystem restoration.
Seeds are removed from the 16th bottle in Professor Beal's collection and germinated and grown Image source: Reference 3
Professor Beale originally designed the experiment to provide a reference for agriculture to understand the life cycle of weed seeds in the field. But over time, the significance of this experiment has gone beyond its original purpose to provide us with important insights into the long-term preservation of seeds and the improvement of the ecological environment. The experiment is expected to end in 2100, and there are still 4 glass bottles waiting to be discovered by scientists.
epilogue
These stories of seeds, from millennial resurrections in ancient ice and desert rubble to centennial experiments at Michigan State University, not only demonstrate the immortal power of seeds as the origin of life, but also reveal the subtle interweaving of life and time in nature.
Spanning millennia, these seeds have served as a bridge between us and the past, as well as an important symbol of scientific exploration and nature conservation. They teach us to respect nature, remind us of our responsibility to maintain the ecological balance of the planet, and show the endless wonders of the natural world waiting to be explored, understood and protected.
bibliography
[1] Yashina et al. Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost. PNAS. 2012, 109(10), 4008-4013.
[2] Sallon et al. Germination, genetics, and growth of an ancient date seed. Science. 2008, 320, 1464.
[3] Fleming et al. The 141‐year period for Dr. Beal's seed viability experiment: A hybrid surprise. Am Journal of Bot. 2023, 110: e16250.
Planning and production
This article is a work of popular science China-Star Project
Produced by the Department of Science and Technology of the China Association for Science and Technology
Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Galaxy Culture Media Co., Ltd
Author丨Denovo Science Team
Review丨Wang Kang, Director of the Science Museum of the National Botanical Garden
Planning丨Ding Kun