These plants can photosynthesis in the depths of the Arctic even without light
Original version of This story Appears in Quanta Magazine.
Most of the engines of life are sown in the sun. Photons are filtered out in the atmosphere and are eagerly absorbed by light-driven organisms such as plants and algae. Through photosynthesis, particles of light power are a cellular reaction that produces chemical energy (in the form of sugar) and then circumvents the food web in complex dances such as food, predators, scavengers, decomposition agents.
On a clear sunny day, there are many photons to walk around. But what happens in low light? Biologists have long had little photosynthesis, or how many photons it needs to reach, and how quickly the cells’ photosynthetic machinery adds carbon dioxide to oxygen and energy. The calculations show that the theoretical minimum is about 0.01 mg of photons per second, or one thousandth of a sunny day.
For decades, this calculation has been theoretical given the difficulty of studying photosynthesis in low light. Although there are many places on Earth that are barely accessible, no one can confirm it in the wild. Every winter, winters in the High Arctic, such as the tilting sun on Earth, disappear for several months. Sea ice covers sea ice and blocks incoming light, leaving the cold ocean behind the dark colors inside the grave. Biologists believe that there, photosynthesis microalgae live throughout the season and wait for warmth and light to return.
“People think it’s a polar night because these desert conditions are very little, and everything is sleeping, hibernating, waiting for the next spring,” said Clara Hoppe, a bio-earth player at the Alfred Wegener Institute in Germany. “But in reality, people never really saw it.”
In the winter of 2020, Hoppe spent months lying on ice on a boat, studying the limits of photosynthesis in the dark all night. Her team’s recent research on natural communications reported that microalgae grew and reproduced at or near the theoretical minimum at light levels, lower than previously observed in nature.
The study shows that in the coldest and darkest places on Earth, the light of life blooms in full bloom. “At least under certain conditions, at least some phytoplankton may be able to do something very useful in very low-key situations,” said Douglas Campbell, an expert on aquatic photosynthesis at Mount Allison University in Canada, who is not involved in the research. “This is an important job.”
The power of the dark side
Traditionally, scientists understand the Arctic as a stagnant place for most of the year. In winter, creatures that can escape the cold water will do so. Those who live in stored reserves or silent sleep. Then, when the sun returns, the place regains life. During the spring blooms, photosynthesis of algae and other microorganisms initiate the rise of Arctic ecosystems, with a year of carnival every year, with tiny crustaceans, fish, seals, birds, birds, polar bears, whales, and more.
It seems that Hoppe, any plankton that can be more successful than the competition, can have a more successful summer. This made her wonder, to be precise, when an organism could respond to the light of light.
