Unlocking the Genetic History of Grasses for Future Food Security Solutions

An international team of scientists, including Donald Danforth Plant Science Center Member Emerita Elizabeth "Toby" Kellogg, PhD, has produced a chromosome-level genome assembly that offers a new view of the earliest evolution of grasses, the plant family that includes many of the world's most important food crops.

Published in Nature Communications, the study, "Chromosome-level Streptochaeta genome elucidates the ancestral karyotype and allopolyploid origin of grasses," reports the genome of Streptochaeta spicata, a tropical grass from a lineage that branched off near the base of the grass family tree. Because of that pivotal position, Streptochaeta gives researchers an unusually clear window into the genome of the common ancestor of living grasses.

Grasses are the world's most economically important plant family and include rice, wheat, maize, sorghum, barley, sugarcane, and many forage and bioenergy crops. Reconstructing their deep evolutionary history gives scientists a foundation for understanding how important traits emerged and changed over time. That knowledge can inform future efforts to use the genetic diversity of crops and their wild relatives to address challenges in food security and environmental sustainability.

By comparing the Streptochaeta genome with genomes from across the grass family, the researchers uncovered new evidence about the ancient genetic events that shaped all living grasses. The findings offer a clearer picture of how grasses evolved and diversified into the plant family that includes many globally important crops.

Grasses provide much of the food on which people around the world depend, but the earliest chapters of their evolutionary history have been difficult to reconstruct. All grasses bear the footprint of a time when the total number of their genes doubled. The effect of that duplication is still visible in all of today's cereal crops. The grasses have been called a single genetic system, meaning that discoveries in one crop often turn out to apply to others. This study shows how the ancestral grass genome underpins the extraordinary diversity of modern grasses."

Emerita Elizabeth "Toby" Kellogg, PhD, Member, Donald Danforth Plant Science Center

Kellogg joined the Danforth Center as a principal investigator in 2014 and is the Robert E. King Distinguished Investigator. The National Academy of Sciences elected her in 2020, and her research on the comparative biology of cereal crops and their wild relatives has earned her international recognition. Her work has helped explain the evolutionary history of grasses and how researchers can use their natural genetic diversity to unlock the potential of crops.

"Toby's career demonstrates how fundamental discoveries about plant diversity and evolution can expand what is possible in crop science," said Giles Oldroyd, PhD, president of the Danforth Center. "This study advances the knowledge needed to develop crops that can nourish a growing population while using resources more sustainably, directly reflecting the Danforth Center's mission."

Researchers at Shandong Agricultural University and the Kunming Institute of Botany, Chinese Academy of Sciences, led the study, with collaborators from the Xishuangbanna Tropical Botanical Garden, University of Chinese Academy of Sciences, University of Edinburgh, Royal Botanic Garden Edinburgh, and the Danforth Center.