Campus News

Study uses DNA sequences to examine key events in plant evolution

Scientists from North America, Europe and China have published a paper in the Proceedings of the National Academy of Sciences that reveals important details about key transitions in the evolution of plant life on Earth.

From strange and exotic algae, mosses, ferns, trees and flowers growing deep in steamy rainforests to the grains and vegetables humans eat and the ornamental plants adorning people’s homes, all plant life on Earth shares over a billion years of history.

“Our study generated DNA sequences from a vast number of distantly related plants, and we developed new analysis tools to understand their relationships and the timing of key innovations in plant evolution,” said study co-author Jim Leebens-Mack, an associate professor of plant biology in the Franklin College of Arts and Sciences.

As part of the One Thousand Plants, or 1KP, initiative, the research team is generating millions of gene sequences from plant species sampled from across the green tree of life. By resolving these relationships, the international research team is illuminating the complex processes that allowed ancient water-faring algae to evolve into land plants with adaptations to competition for light, water and soil nutrients.

Lead author Norm Wickett of the Chicago Botanic Garden said the study was “like taking a time machine back to get a glimpse of how ancient algae transitioned into the diverse array of plants we depend on for our food, building materials and critical ecological services.”

“When plants colonized the land 450 million years ago, it changed the world forever,” said Simon Malcomber, program director in the National Science Foundation’s Division of Environmental Biology, which funded the research. “The results of this study offer new insights into the relationships among living plants.”

As plants grew and thrived across the plains, valleys and mountains of Earth’s landscape, rapid changes in their structures gave rise to myriad new species. The group’s data helps scientists better understand the ancestry of the most common plant lineages, including flowering plants and nonflowering, cone-bearing plants such as pine trees.

The investigation also has revealed a number of previously unknown molecular characteristics of some plant species that may have applications in medicine and industry.