U of C study showcases impeded iron intake in canola from drought

Glacier FarmMedia – New research by scientists at the University of Calgary has found plants, including canola, rice and tomatoes, actively shut down their own ability to take in iron when they experience drought.

It is a finding that could have implications for the nutritional value of agricultural crops.

The study, published in the journal Cell, questions whether plants send out a “cry for help” when they are stressed by drought to recruit beneficial soil microbes like bacteria and fungi in their roots.

“We found this shift is the result of specific changes to plant roots,” said Connor Fitzpatrick, lead author on the study and an assistant professor in the Department of Biological Sciences with U of C’s Faculty of Science, in a press release by the post secondary institution.

“It happens because plants, under drought stress, dial down both their immune systems and their iron uptake machinery.”

Why it Matters: As agricultural producers look for greater yields while combating drought, research aiding the nutrient quality of the yield through drought is just as important to help with food security.

Fitzpatrick added it allows a particular group of bacteria, called streptomyces, to thrive — but it does not automatically mean healthier plants. Some streptomyces strains help, while others hinder.

“Together, this leads to a new way of thinking about plant-microbe interactions during drought,” said Fitzpatrick.

“Drought doesn’t just stress plants. It fundamentally rewires how they manage nutrients and interact with the microbial world around them.”

Canola

The research is important for plant biology, but also provides insight into global food security and human nutrition.

“Iron deficiency is already one of the most widespread nutritional disorders in the world, affecting billions of people. Much of the iron in human diets comes from plants such as cereals and legumes,” said Fitzpatrick.

“At the same time, drought is increasing in frequency and severity across many agricultural regions due to climate change.”

Fitzpatrick, who did his post-doctoral work at the University of North Carolina at Chapel Hill and finished the research at the U of C, theorized the research suggests the challenges could be more connected than previously thought.

“It means drought may not only reduce crop yield, but also reduce the nutritional quality of crops by limiting iron in edible tissues.”

Staple crops provide a large share of global calories, and in many regions they are also important targets for improving micro-nutrient intake. If drought reduces iron uptake or lowers iron accumulation in edible tissues, then climate stress could compound existing nutrition challenges, particularly in populations already vulnerable to iron deficiency.

“I would frame this as a growing risk rather than an immediate crisis. The key message is climate resilience in food systems should include nutritional resilience, not only yield stability,” said Fitzpatrick in a follow up e-mail with Alberta Farmer Express.

Fitzpatrick noted the research team found the reduction in iron uptake as they were trying to understand microbial enrichment in plant roots.

The team initially used a model organism, Arabidopsis thaliana, also known as thale cress or “the fruit fly of the plant world,” and later demonstrated it across a wide variety of plants.

The research opens the door to creating probiotic soil treatments or ways of breeding crops that sustain iron uptake during a drought.

Many breeding efforts focus on increasing the iron content of staple crops such as cereals, legumes and rice. The study suggests drought can actively suppress the plant’s own iron uptake machinery, meaning a crop variety with high iron content under well-watered conditions may not necessarily maintain that advantage during drought. For nutrition-focused breeding, it is selecting crop varieties that maintain iron uptake and iron allocation to edible tissues under water stress.

“The final impact on edible tissues will likely depend on the crop, the timing and severity of drought, soil chemistry, baseline iron availability, and the developmental stage when stress occurs,” said Fitzpatrick.

“Drought during early root development may have different consequences than drought during grain filling. At this point, we can say that drought has the potential to reduce crop iron nutrition, but more field and crop-specific work is needed to estimate the magnitude of that effect in food products.”

For agricultural use, it means microbial products need to be tested across different crops, soils, climates and native microbial communities.

“There is real promise, but for the specific goal of maintaining iron uptake during drought, we are still in the translational research phase rather than at the point of a universal field-ready product,” said Fitzpatrick.

Moving from mechanism to application, researchers will test major crops under realistic greenhouse and field conditions to determine whether drought reduces iron accumulation in edible tissues, and by how much.

Also, the plant genes and regulatory pathways that control the drought-induced lessening of iron uptake will need to be identified.

“Overall, these findings suggest that protecting food security under climate change should include both yield and nutrition. Growers, breeders and the food industry will increasingly need tools that preserve not only how much food is produced, but also the nutritional quality of that food.”