Soybeans account for roughly two-thirds of plant-based protein meal output worldwide. Canada exports 70% of its soybean crop each year, making it one of the country's top three crops by value. But despite a dramatic rise in soy production over recent decades, the protein content of the seeds has not kept pace.
That gap is what Brazilian scientist Gabriel Montanha and his colleagues set out to address. Their findings, published in the journal ACS Agricultural Science & Technology and featured on the cover of the journal's current issue, point to two specific minerals as key players in soybean protein formation: zinc and sulfur.
According to Phys.org, Montanha, who is completing a postdoctoral fellowship at the European Synchrotron Radiation Facility in Grenoble, France, said soy production has "exploded" in recent decades. He argues that simply growing more soy is not a sustainable path forward.
"To ensure soy remains a sustainable crop, we need to increase the protein content of soy seeds," Montanha said. "It's critical we find ways to generate more protein without increasing the amount of land we're currently cultivating."
To investigate what drives protein content inside the seed, Montanha and colleagues used two synchrotron facilities: the Canadian Light Source at the University of Saskatchewan and Brazil's National Synchrotron Light Laboratory. Synchrotron imaging allows researchers to examine the internal structure and chemical composition of biological materials at a level of detail not possible with conventional tools.
The team looked at four types of soybean seeds, mapping where proteins and minerals were located inside each one. A clear pattern emerged.
"We could see that the genotypes that had higher protein content also had higher zinc and sulfur," Montanha said.
The research was conducted as part of Montanha's PhD work, alongside collaborators at Brazil's University of São Paulo and Sapienza University of Rome in Italy.
Montanha credited the imaging technology for moving the research forward. "The use of these different tools for structural and chemical imaging of biological materials really pushed us forward to understand the role of the nutrients in the plant's physiology," he said.
The team is not waiting to apply what they found. Montanha and colleagues are already developing fertilization techniques designed to ensure soybean seeds have access to sulfur and zinc at critical stages of their development. The goal is to boost protein content through targeted nutrient delivery rather than by expanding the land under cultivation.
