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February 26th, 2019 / The Scientist, US

The corn Elsbeth Walker grows looks a bit strange. Its leaves are streaked with yellow, instead of being entirely green. This yellow-streaked corn is a mutant that has trouble taking in iron, making it hard for the plant to create chlorophyll, a green pigment involved in photosynthesis.

Walker, a molecular biologist at the University of Massachusetts Amherst, and her colleagues are studying the yellow-striped corn to learn more about how iron transport works in plants. The information they glean, she says, could help researchers genetically engineer corn and other staple grains to take in more of the mineral, and, ultimately, deliver it to people who lack sufficient iron in their diets.

“The places in the world where iron nutrition is really problematic are places where people are very under-resourced and are practicing subsistence agriculture,” Walker says. “In those areas, people are often eating very, very little meat—if any at all—and they’re also typically relying on rice or corn or another staple for the vast majority of their calories.” Such grain products take up very little iron from the soil, so people who rely on these products for a large part of their diets often do not get enough of the mineral.

Iron deficiency has numerous health implications, including stunting child development, particularly brain development, and health complications for menstruating women and pregnant women trying to support a healthy fetus, Walker explains. According to the World Health Organization, anemia—a condition commonly caused by iron deficiency—affects 1.62 billion people globally, almost 25 percent of the human population, and leaves them particularly susceptible to death from other diseases.

To combat iron deficiency, plant scientists and bioengineers have been looking for ways to boost iron levels in the foods iron-deficient individuals eat. The strategy is called biofortification, and so far, scientists have had some success selectively breeding plants, especially bean and rice plants, to take in more of the mineral. However, Walker and other molecular biologists and geneticists are looking at how they could tweak plants’ DNA to make the seeds sequester higher levels of essential vitamins and minerals. Read more