How Drought Reshapes Roots: Reduced Iron Uptake in Major Food Crops
A new study by scientists at the University of Calgary has revealed that plants — from canola to rice to tomatoes and other species — actively shut down their ability to take up iron when experiencing drought. This finding could have significant implications for the nutritional value of agricultural crops. The study, published in the journal Cell, examines whether plants send out a “cry for help” to attract beneficial soil microbes, such as bacteria and fungi, to their roots when stressed by drought.
Research conducted by scientists at the University of Calgary has found that plants—from canola to rice, tomatoes and other varieties—actively shut down their iron absorption abilities when experiencing drought. This finding could have significant implications for the nutritional value of agricultural products. Published in the journal Cell, the study examines whether plants, when stressed by drought, send out a "help signal" to their roots to attract beneficial soil microorganisms (such as bacteria and fungi).
Dr. Connor Fitzpatrick, lead author of the study and currently an assistant professor in the Department of Biological Sciences at the University of Calgary's Faculty of Science, states: "We found that this change is a result of specific alterations in plant roots. This occurs because plants slow down both their immune systems and iron uptake mechanisms when under drought stress."
Fitzpatrick notes that this condition allows for the development of a special group of bacteria called Streptomyces, but this does not automatically mean healthier plants. He explains that some Streptomyces species are beneficial, while others interfere with the process.
"All of this opens up a new way of thinking about plant-microbe interactions during drought," says Fitzpatrick, adding: "Drought not only stresses plants, but fundamentally restructures how they manage nutrients and interact with the microbial world around them." Fitzpatrick states that beyond being important for plant biology, the research also sheds light on global food security and human nutrition.
According to Fitzpatrick, "Iron deficiency is already one of the most common nutritional disorders in the world, affecting billions of people. A large portion of iron in the human diet comes from plants such as grains and legumes. At the same time, climate change is increasing the frequency and severity of drought in many agricultural regions." Fitzpatrick, who conducted his postdoctoral work at the University of North Carolina at Chapel Hill and completed the research at the University of Calgary, suggests that these challenges may be interconnected in ways previously unanticipated. "This means that drought not only reduces crop yield, but may also diminish the nutritional quality of products by limiting iron in edible tissues."
Fitzpatrick explains that the research team noticed this decrease in iron uptake while trying to understand microbial enrichment in plant roots. The team experimentally manipulated drought stress and iron availability to solve the mechanism, initially using the model organism Arabidopsis thaliana, known as the fruit fly of the plant world, and later demonstrated the condition across a diverse range of plants. Fitzpatrick states: "We showed this for rice, we showed it for tomatoes, and more recently we showed it for canola."
Fitzpatrick adds that this research has opened doors toward creating probiotic soil treatments or cultivating crop varieties that maintain iron uptake during drought.
Source
Connor R. Fitzpatrick et al, Streptomyces enrichment in roots during drought is uncoupled from plant benefit and is driven by host suppression of iron uptake and immunity, Cell (2026). DOI: 10.1016/j.cell.2026.04.027 / Journal information: Cell / https://phys.org/news/2026-06-drought-rewires-roots-iron-uptake.html
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