Researchers at the University of Calgary have identified a mechanism that causes plants to reduce their ability to absorb iron during periods of drought, a discovery that could have significant implications for crop nutrition and food security.
The study found that plants including canola, rice and tomato actively suppress iron uptake when exposed to drought stress. The research also examined how drought alters interactions between plant roots and soil microbes.
According to the research team, drought triggers specific changes in plant roots that reduce both immune system activity and the machinery responsible for iron absorption. These changes create conditions that allow certain groups of soil bacteria, particularly Streptomyces, to become more abundant around plant roots.
Researchers found that the presence of Streptomyces does not necessarily benefit plants. While some strains may support plant health, others can interfere with plant functions, suggesting that drought-driven shifts in microbial communities have complex effects on crop performance.
The findings challenge previous assumptions about how plants respond to drought and suggest that water stress fundamentally alters the way plants manage nutrients and interact with microorganisms in the soil.
The research also highlights potential consequences for human nutrition. Iron deficiency remains one of the most common nutritional disorders worldwide, and many dietary sources of iron come from plant-based foods such as cereals and legumes. At the same time, drought events are becoming more frequent and severe across many agricultural regions.
Researchers said the results indicate that drought may affect not only crop yields but also the nutritional quality of harvested crops by reducing iron accumulation in edible plant tissues.
The discovery emerged as scientists investigated why certain microbial populations become enriched in plant roots during drought conditions. To identify the underlying mechanism, the team experimentally manipulated both drought stress and iron availability.
The study began with the model plant *Arabidopsis thaliana* and was later expanded to include several crop species. Researchers confirmed similar drought-related reductions in iron uptake in rice, tomato and canola.
The findings could support future development of probiotic soil treatments designed to improve plant performance under drought conditions. The research may also contribute to crop breeding efforts aimed at maintaining iron uptake during periods of water stress.
In related work, study author Connor Fitzpatrick and fellow University of Calgary biological sciences researcher Jackie Lebenzon recently received funding through the Canola Agronomic Research Program.
Fitzpatrick's project will focus on Verticillium longisporum, the fungus responsible for Verticillium stripe, a disease that causes significant damage in canola production. Lebenzon's research will examine the overwintering physiology and population dynamics of flea beetles, a major pest affecting canola crops.
The projects are intended to generate new approaches for managing pests and diseases while helping the canola sector address emerging threats, including weeds and viral infections.
Source: University of Calgary, "Research shows plants such as canola, tomatoes and rice reduce iron uptake when stressed by drought"