Study Finds How Flowering Plants Cope with Cold

Plants adopting traits to survive cold has always puzzled scientists. Now, a vast database sheds light on plants' evolutionary behavior that helped them survive in colder regions of the world.

Researchers at George Washington University's Columbian College of Arts and Sciences and colleagues have used the database to track the evolution of several flowering plants.

The study also shows that modern flowering plants, including crops and trees, may not have the required traits to quickly adapt to human-induced climate change, researchers said in a news release. 

Early flowering plants had woody stems and mostly grew above the ground. Also, these plants mostly grew in warm and wet lands. However, with time, these plants began moving into other regions, adopting several changes on their way. One of these changes was to avoid freezing at all costs.

"Freezing is a challenge for plants. Their living tissues can be damaged. It's like a plant's equivalent to frostbite. Their water-conducting pipes can also be blocked by air bubbles as water freezes and thaws," said Amy Zanne, the study's lead author and an assistant professor of biology in the George Washington University's Columbian College of Arts and Sciences.

The team identified three traits commonly found in plants living in non-tropical regions. The flora dropped leaves during winters; made leaner water-conducting pathways or avoided the cold by hiding in the form of seeds or underground storage organs such as tomatoes.

For the study, researchers first created a vast database of 49,064 species and looked at how a genus survives cold. They then used Global Biodiversity Information Facility to find out whether the plant was exposed to cold during its evolution.

They then collected additional data on evolution of 32,223 species of plants. The team used all the data to create a model that could allow them to analyze a species' evolutionary traits and climate. This "timetree," can be seen at One Zoom.

"Until now, we haven't had a compelling narrative about how leaf and stem traits have evolved to tolerate cold temperatures," Zanne said in a news release. "Our research gives us this insight, showing us the whens, hows and whys behind plant species' trait evolution and movements around the globe."

Scientists plan to use this data to see how plants evolve to cope with other environmental pressures besides freezing.

The study is published in the journal Nature.