The story of seed germination on Mount Everest

Researchers walk on a moraine ridge at an altitude of more than 5,900 meters. Photo by Guo Yongjie (People's Vision)

Snow rabbit covered in ice and snow. Photo by Guo Yongjie (People's Vision)

Last September, Chinese researchers successfully collected seeds of the Sumeru fan-leaved mustard at 6,212 meters at the East Rongbuk Glacier on Mount Everest, setting a new record for the highest altitude for plant seed collection in my country.

In July this year, the five species of Mount Everest plant seeds collected and stored in a cold storage at minus 20 degrees Celsius for nearly a year all germinated successfully. This means that my country has successfully collected and preserved the seeds of the plants with the highest altitude in the world, laying a foundation for future research on related germplasm resources.

At 6,212 meters above sea level, snow-capped peaks stretch out. Even the rocky beach under Mount Everest is covered by snow all year round. Strong winds, extreme cold, lack of oxygen... Can we still find traces of life in this "forbidden zone of life"?

In September 2021, at 6,212 meters at the East Rongbuk Glacier of Mount Everest, researchers from the Southwest China Wild Organisms Germplasm Bank (hereinafter referred to as the "Germ Bank") of the Kunming Institute of Botany, Chinese Academy of Sciences, successfully collected seeds of the mustard plant during a botanical scientific expedition, setting a new record for the highest altitude for plant seed collection in my country.

After being stored in a cold storage at -20 degrees Celsius for nearly a year, researchers decided to conduct a germination experiment on the seeds. Can the seeds of the plant be "reawakened" and become the highest-altitude plant seeds successfully preserved in the world?

The collection was conducted at 6212 meters, breaking the record of the highest altitude for collecting plant seeds in my country.

Finding seeds requires patience and courage, and sometimes a little bit of luck.

On September 24, 2021, a team of eight people including Guo Yongjie and Zhao Yanhui, members of the germplasm bank's collection team, climbed Mount Everest again to challenge my country's highest altitude record for plant seed collection.

By the end of September, it is already autumn and the days are getting cooler, but for the plants on Mount Everest, it is the best phenological period for collecting seeds.

Previously, there were 15 species of plants collected at an altitude of more than 6,100 meters, most of which were collected by foreign scholars. The collection team not only had to find plants, but also collect mature seeds, which greatly increased the difficulty.

The destination of this trip is the gravel beach of the East Rongbuk Glacier on Mount Everest. The cracks between the rocks are the most promising areas for discovering plants. Starting from the transition camp at an altitude of 5,800 meters, the heavy snow blurred the ice cracks underfoot. Every step of the climb to Mount Everest requires the collection team to be extremely cautious.

When we climbed to an altitude of about 6,200 meters, several hours had passed since the collection team set out. The accompanying guide hummed an ancient local ballad, while the collection team bent over and carefully searched.

"Sumeru fan-leaved mustard!" Guo Yongjie recognized the camouflaged plant at a glance in the cracks of the gravel. He half-knelt and half-crouched to take pictures of the Sumeru fan-leaved mustard from various angles, and carefully recorded the altitude and other location information of the collection site - 6,212 meters above sea level, this is the first plant the collection team has seen at an altitude of more than 6,000 meters. What made Guo Yongjie even happier was that some of the siliques of this Sumeru fan-leaved mustard had cracked, which also meant that the collection team had a chance to collect seeds of this plant.

At this time, Mount Everest happened to reveal its true appearance in the distance. Guo Yongjie couldn't help but gently lift the plant in his hand. The small and fragile branches and leaves swayed in the wind, facing the towering snow-capped mountains in the distance. Mount Everest is awe-inspiring, but the tenacity of life is no less than that of Mount Everest.

Finally, the collection team reached the altitude of 6605 meters on Mount Everest, but unfortunately found no trace of plants. The seeds of the mustard plant collected this time set a new record for the highest altitude for collecting plant seeds in my country.

Stored at -20 degrees Celsius, seeds can survive for decades or even thousands of years

In fact, in August 2021, the Germplasm Bank launched the world's highest altitude plant seed collection action plan, and in September of that year, researchers went to Mount Everest for the second time. As a national strategic biological resource, the collected Mount Everest plant seeds were quickly sent to the Germplasm Bank in Kunming.

According to the standards of the germplasm bank, a complete seed sample requires at least 2,500 seeds, and 10,000 seeds are optimal. However, plant seeds in the high-altitude areas of Mount Everest are extremely scarce and cannot meet the basic requirement of 2,500 seeds. So we can only collect and preserve as many as possible.

Every seed is very precious and must be preserved and handled with great care. "The time, location, longitude and latitude, altitude, species information, initial quality and quantity of the seeds must be entered into the database in a timely and accurate manner so that they can be used in future research and ecological restoration," said Qin Shaofa, leader of the seed management team at the Germplasm Bank.

Qin Shaofa and his team put the seeds of plants such as Sumeru fan-leaved mustard and snow rabbit into the main drying room after counting and weighing them. After being stored in an environment with a temperature of 15 degrees Celsius and an air humidity of 15% for a month, the moisture content of the seeds dropped to about 5%.

Under low temperature and dry conditions, precious seeds of plants such as Sumeru fan-leaved mustard and snow rabbit entered a "dormant period" and were then sealed and packaged and sent to cold storage for long-term preservation. "Under a constant temperature of minus 20 degrees Celsius, these seeds are expected to survive for decades or even thousands of years," said Qin Shaofa.

"The germplasm resources on Mount Everest are very unique, and the genes they contain are very rare. It is precisely because of their rarity that we need to overcome difficulties and give priority to collecting and preserving them," said Cai Jie, director of the Germplasm Bank's Preservation Center. In addition, within the 3,700-4,700-meter altitude range, the collection team also collected more than 40 kinds of wild plant seeds, all of which have been stored in the bank.

"As a national strategic biological resource, the collection and preservation of seeds in the Mount Everest region will help protect the species and genetic diversity in the Mount Everest region, and at the same time provide raw materials for the research and utilization of related germplasm resources in the future," said Cai Jie.

Seeds of 5 wild plants in the Everest region all germinated successfully

In July this year, after being stored at low temperatures for nearly 10 months, seeds of five wild plants in the Mount Everest region, including mustard, snow rabbit, Tibetan sea buckthorn, artemisia annua, and spiny pea, were taken out from the cold storage by seed germination manager Yang Juan. After being placed in a drying room to warm up, some of them were carefully placed on the agar culture medium.

"To ensure that the seeds stored in the germplasm bank are alive, each seed will be sampled and tested for vitality at regular intervals." Yang Juan said that 10 months after the collection of Mount Everest plant seeds, five types of "Mount Everest seeds" including the highest altitude seed, Mustard fern, ushered in the first germination experiment.

This experiment is crucial. If the seeds germinate successfully, it will prove that the seeds of wild plants in the Everest region have been effectively preserved. In fact, foreign researchers have previously collected seeds from higher altitudes, but the seeds failed to germinate after being stored in cold storage for a period of time. If the Sumeru fan-leaved mustard can germinate successfully, it means that this is the highest altitude seed successfully preserved in the world.

For the sake of popular science, the reporter recorded the entire seed germination process using a macro camera and time-lapse photography. However, no one can guarantee whether plant seeds from extremely high altitude areas can germinate at an altitude of 1,900 meters after being frozen for nearly a year.

In the first two days, the five kinds of seeds barely moved except for absorbing water and growing larger. But Cai Jie's words relieved the team's worries: "The climate in the Everest region is harsh and changeable. In order to complete the life cycle as quickly as possible, the seeds should germinate faster."

Sure enough, starting from the third day, the radicle ends of many seeds began to show some changes; two days later, the radicle of Tibetan sea buckthorn was the first to break through the seed coat and grow downward; the seeds of plants such as Sumeru fan-leaved mustard and snow rabbit also broke through the seed coat one after another, and the embryo and cotyledons slowly stretched out and grew into seedlings.

In just 9 days, all the seeds of 5 wild plants in the Everest region germinated successfully. In particular, the germination of the Sumeru fan-leaved mustard proved that my country had successfully collected and preserved the seeds of the plants with the highest altitude in the world.

The germplasm bank not only preserves the seeds of Mount Everest plants, but also tens of thousands of precious germplasm resources. Since its operation, the germplasm bank has preserved 87,863 copies of 10,917 species of wild plant seeds in my country, and 36% of the total number of flowering plant species in my country are backed up here.

A seed, from the moment it is born, carries the hope of life. The seeds treasured in the Southwest China Wildlife Germplasm Resource Bank undoubtedly bring more hope to biodiversity conservation.

(Originally published in People's Daily, 2022-12-21, p. 13)