New Research Links Corn’s Cellular Gene Activity to Better Crop Traits
A new study led by the University of Michigan (U-M) reveals how gene activity in specific maize cell types can help explain the visible traits that matter most to growers — including yield potential and adaptability.
The research, published in Science, analyzed DNA from nearly 200 maize lines. It uncovered how gene regulation — not just the genetic code itself — drives differences in traits like ear size and number.
“One of the things that’s really remarkable to me is that, maybe a decade ago, when these sort of studies first started coming out, we were just trying to associate a genetic change to how the phenotypes would change,” U-M assistant professor of molecular, cellular and developmental biology Alexandre Marand said in a U-M news release.
“What this study shows is that, actually, most phenotypic variation comes from changes to regulation of a gene: when the gene is expressed, where it’s expressed and how much of it is expressed,” he said.
In other words, even though all cells share the same DNA, they use that genetic information differently. That disconnect — between the genome and the trait — has long puzzled scientists, especially when visible plant differences weren’t fully explained by genetic variation alone.
Researchers first sequenced the corn genome more than 15 years ago. Since then, the tools to study genes have become increasingly refined. But the missing piece, Marand said, has been understanding how genes operate within individual cells.
That capability has accelerated in just the past five years. This latest study, which began when Marand was a postdoctoral scholar at the University of Georgia, represents a leap forward.
“It’s really about connecting the dots,” he said.
Two postdocs in his U-M lab — Luguang Jiang and Fabio Gomez-Cano — helped push the project to completion. Their work examined gene regulation in specific cell types and how it correlates with traits breeders care about.
“Now that we can make those connections, we can tease apart the different cell contexts and we can start to put things together to optimize plants or to optimize some trait that we’re interested in,” Marand said.
He compared it to understanding how a car works. Knowing what each part does is one thing. Understanding how they function together — and how changes to one affect the whole — is something else entirely.
“This really helps with prediction,” he said. “It lets us ask beforehand, ‘If we make changes, are they going to be additive or even synergistic?’ Will it be one plus one equals two? Or maybe it’s 10 — or negative 20.”
The study also helps illuminate how corn evolved as it spread from tropical regions to temperate zones like Michigan.
“What we found is that a lot of those changes involved changes to the regulatory sequences that we were studying, and they have unique consequences in very specific types of cells,” Marand said. “We can use that information to continue to improve plants and to make corn more adaptable to different climates.”
Contributors to the study included researchers from the University of Georgia and the University of Munich. Funding support came from the National Institutes of Health, the National Science Foundation and the University of Georgia Office of Research.
