The oldest plant root stem cells have been discovered by Oxford University scientists in a 320 million-year-old fossil of an ancient giant plant. Scientists call the stem cell fossil Radix carbonica, which means coal root in Latin.

The study published on June 2 in the journal Current Biology states that the stem cells have a unique pattern of cell division, which is different to the ones observed in other plants present today. Consequently, this provides us a glimpse into how ancient roots grew hundreds of millions of years ago.

“I was examining one of the fossilised soil slides held at the University Herbaria as part of my research into the rooting systems of ancient trees when I noticed a structure that looked like the living root tips we see in plants today,” tells Alexander (Sandy) Hetherington, a Ph.D. student at Oxford Plant Sciences, of his discovery. “I began to realize that I was looking at a population of 320 million-year-old plant stem cells preserved as they were growing – and that it was the first time anything like this had ever been found.”

plant stem cells

Forest. Credit: Pexels

The roots apparently played a role in of the most drastic climate change on Earth. The deep rooting systems actually increased the chemical weathering of the silicate minerals found in rocks, absorbing carbon dioxide from the atmosphere and consequently causing an ice age.

“These fossils demonstrate how the roots of these ancient plants grew for the first time,” adds the study’s senior author Liam Dolan, who is a professor as well as the head of the Department of Plant Sciences at Oxford University. “It is startling that something so small could have had such a dramatic effect on the Earth’s climate.”

The fossil is part of the collection at the Oxford University Herbaria. The research team at this department studies the taxonomy, biodiversity, and conservation of different plant species around the globe.