What if the addition of several cell layers within the corn kernel significantly enriched it with essential nutrients such as iron, zinc and protein? It may benefit people who rely on corn for the majority of their diet.
In a new study, University of Illinois scientists show that simply adding a layer of cells to bran can increase iron by up to 35% and zinc by up to 15% compared to the parent strain. increase.
“For years, people have used traditional methods to breed corn that is high in micronutrients and protein. The point is, why didn’t you do this long ago? It’s very simple,” said co-author of the study, Crop Department, part of U of I’s Department of Agriculture, Consumer and Environmental Sciences (ACES). said Jack Juvik, professor of the department.
Juvik and co-author Michael Paulsmeyer, now postdoctoral scientists at the USDA, focused on the aleurone layer. The aleurone layer is usually a single cell layer just inside the outer coating of the corn kernel. Although only about 2% of the total grain mass, aleurone is rich in protein and micronutrients.
Several rare maize cultivars naturally produce multiple aleurone layers (MALs), but so far, no one has investigated how these extra layers can be manipulated to affect the nutritional quality of grains. Juvik and Paulsmeyer procured two MAL strains. A yellow variety with 5-6 aleurone layers. A blue variety with three aleurone layers from the Maize Genetics Collaborative Stock Center. They soon began crossing with conventional maize varieties to learn how the MAL trait is inherited and how it alters the nutritional value of grains.
By examining how MAL was expressed in the offspring of those crosses, the team traced MAL to a small section of maize chromosome 8, but also found other genetic regions that contribute to traits. The researchers then developed molecular markers to rapidly identify his MAL gene for future breeding programs.
“Using molecular markers, we can take a small sample from the seed and do a DNA analysis to determine if the seedling has the desired trait,” explains Juvik. “It saves a lot of time and energy compared to traditional breeding where you have to plant every seed you have and wait until it matures to see if the trait is there.”
Researchers also tested the nutritional quality of MAL offspring compared to single aleurone-stratified parents. In addition to higher iron and zinc, offspring from blue MAL parents produced 20-30% more anthocyanins. Anthocyanins are red to purple pigments that are prized as natural alternatives to artificial colors in the food manufacturing industry.
For years, Juvik has worked to increase the anthocyanin content of maize, but he focused primarily on the pericarp, the outer layer of the kernel. The light bulb went out when I realized that the aleurone layer also has anthocyanins.
“In some cases, aleurone may contain genes that can produce anthocyanins. That was actually the original intention of this project,” says Juvik. “But when I sent the sample in for micronutrient analysis, lo and behold, there was a very large increase in iron and zinc.”
Juvik says MAL is a simple and promising trait for increasing nutrient and anthocyanin content in maize, but notes that it is not yet ready for the full season. For this study, the team crossed his MAL maize line with maize with low levels of iron and zinc. If he introduced the MAL trait into hybrids with higher levels of those micronutrients, would the increase appear less dramatic?Juvik isn’t sure, but he’s working to find out. increase.
He is now using genetically identical maize hybrids to further isolate the effects of MAL on nutritional quality and anthocyanin content. We then plan to introduce the trait into hybrids that are locally adapted to regions in the Southern Hemisphere where fortification is most beneficial.
“We hope to improve the zinc and iron content to levels that provide enough micronutrients to overcome nutritional problems, especially for pregnant women and young children. That is the goal. But it looks promising enough to continue this work,” says Juvik.
Original: Add 15-35% more nutritional value to cereals just by adding it to corn bran
Than: University of Illinois School of Agriculture Consumer and Environmental Sciences
