A new study reveals interesting insights into plant biology

A recent study has revealed interesting insights into the evolution of plant biology, effectively rewriting the history of how they evolved over the past billion years.

Published in the magazine Nature plantsThe research reveals that plants gradually evolved their range of anatomical designs over time, interspersed with occasional bursts of innovation to overcome and adapt to environmental challenges.

Such findings upend the long-held belief that the core group of plant species, like animals, evolved in a great wave of abrupt change early in their evolutionary history.

A diverse community of wild plants, from mosses to flowering species, grow together in a bog stream in Cairngorms National Park, Scotland. Image credit: Sandy Hetherington, University of Edinburgh, UK

Co-lead author Philip Donoghue, a professor of paleobiology at UCLA University of Bristol“Although plants are extraordinarily diverse in their design and organization, they share a common ancestor that arose in the sea more than a billion years ago,” he said.

“We wanted to test whether they actually evolved through a big bang early in their history or whether their evolution was a slower, more continuous process. Surprisingly, the results revealed that plant evolution was somewhat patchwork, with long periods of change.” Gradual, interspersed with short periods of large-scale innovation, overcoming the challenges of living on dry land.

To test this theory, the team of scientists analyzed the similarities and differences between 248 groups of plants, ranging from single-celled pond froth and seaweeds to land plants including everything from mosses and ferns to pines, conifers and flowering plants. They also looked at 160 extinct groups known only from the fossil record, including… Classify From the Devonian period, Rhynie Chert, who lived more than 400 million years ago.

More than 130,000 observations were generated by dividing plant designs into their components and recording those present or absent in each of the major groups, living and fossil. Computerized statistical techniques measured the overall similarities and differences between groups and how they differed over time.

moss, Polytrichum vulgarisIt is one of the closest living relatives of the ancestral land plant. Credit: Sylvia Pressel, Natural History Museum

Scientists have also tried to figure out what led to these evolutionary innovations, such as the introduction of spores, seeds, roots, leaves, pollen, and flowers.

Co-lead author Dr James Clarke, a research associate in biological sciences at the University of Bristol, said: “We found that changes in plant anatomical design occur simultaneously with events in which the entire cellular genetic makeup is duplicated. This has happened many times in the history of plant evolution, as a result of errors In the process of copying the genome, creating duplicate copies of genes that are free to mutate and develop new functions.

But the main impulses of plant anatomical evolution have been found to be linked to the challenge of living and reproducing in increasingly arid environments, and to the gradual emergence of plants from sea to land.

Co-lead author Dr Sandy Hetherington’s fascination with the evolution of land plants began as a budding geologist at the University of Bristol and now continues in his work at the University of Edinburgh.

“In general, the pattern of episodic pulses in the evolution of plant anatomy matches what has been seen in other multicellular kingdoms with complex life, such as animals and fungi,” he said. “This suggests that it is a general pattern and blueprint for complex multicellular life from its beginning.”

Reference: “The Evolution of Phenotypic Variation in the Plant Kingdom” by James W. Clark, Alexander J. Hetherington, Jennifer L. Morris, Sylvia Bressel, Geoffrey J. Duckett, Mark N. Bottic, Harald Schneider, Paul Kenrick, Charles H. Wellman and Philip C.J. Donoghue, September 4, 2023, Nature plants.
doi: 10.1038/s41477-023-01513-x