By examining DNA from various cells across nearly 200 maize varieties, a study conducted by the University of Michigan has uncovered insights that may assist farmers in adapting their crops to a rapidly evolving environment.
The recent research led by Alexandre Marand divulges previously concealed details regarding the gene activity within distinct cell types. This yields vital context that enhances comprehension of how the molecular biology of a lineage correlates with its observable characteristics, or its phenotype. Such traits include the number of corn ears on a plant and their size.
“One of the aspects that fascinates me is that, perhaps about ten years ago, when such studies began emerging, we were merely attempting to link genetic modifications to changes in phenotypes,” explained Marand, an assistant professor of molecular, cellular, and developmental biology at U-M. “What this research indicates is that, in reality, most phenotypic variation results from alterations in the regulation of a gene: the timing, location, and extent of its expression.”
Another perspective is that there existed a gap, at an intermediary stage, between our grasp of plant genetics and the attributes of plants.
More than 15 years ago, scientists successfully sequenced the entire corn genome, and since then, they have honed the skill to detect even minor divergence in the genetic code among specimens. However, these molecular-level variations frequently did not account for the significant differences that are crucial to farmers.
Consequently, researchers began to suspect that the manner in which various cells utilized those genes might be influential. While every cell in an organism shares identical genes, different types of cells apply those genes differently.
Within the last five years, the capacity for scientists to explore plant genes within a cellular framework has advanced remarkably, noted Marand. His team’s recent study, published in the journal Science, represents a significant progression in this encouraging trend.
“It’s truly about establishing connections,” stated Marand, who initiated this work a few years prior as a postdoctoral fellow at the University of Georgia. This effort has now reached completion largely due to the contributions of two postdoctoral scholars in his lab at U-M: Luguang Jiang and Fabio Gomez-Cano.
“With these connections established, we can differentiate the various cell contexts and begin to synthesize information to enhance plants or to optimize traits of interest,” Marand remarked.
Comparably, it’s similar to possessing a vehicle; we understood the different components and their functions but lacked insight into their operations. Acquiring that knowledge provides a fresh appreciation for the car’s overall performance—the corn plant in this analogy—and creates new avenues for enhancing its capabilities.
It also facilitates a better understanding of how modifying one element of operation affects others within the system.
“This significantly aids in forecasting,” Marand shared. “It enables us to inquire proactively, ‘If we implement changes, will they yield additive or even synergistic outcomes?’ Will it be a case of one plus one equals two? Or could it be ten—or even negative twenty?”
The findings also grant an early understanding of where optimal chances for synergy may exist. Corn initially emerged in the planet’s tropical regions and has adapted into varieties that can now withstand even Michigan’s more temperate climates.
Through the examination of numerous corn varieties, the new study illuminated many evolutionary transformations, enhancing comprehension of how maize evolved as farmers selected plants that performed best in their surroundings.
“Our findings indicate that many of those transformations involved alterations to the regulatory sequences we studied, and they have distinct consequences in particular cell types,” Marand stated. “We can leverage that knowledge to continue enhancing plants and increase corn’s adaptability to various climates.”
Researchers from the University of Georgia and the University of Munich also played a role in the study, which received support from the National Institutes of Health, the National Science Foundation, and the University of Georgia Office of Research.