The team, co-led by the University of California, Riverside, and the Boyce Thompson Institute, discovered that a single mutation in a regulatory gene allows roots of the model plant Arabidopsis thaliana to grow normally even in highly acidic soil—conditions that typically stunt the plant’s growth and limit nutrient and water uptake.
The findings, published today in the journal Nature Plants, could lead to the development of crops more tolerant to acidic soil, thereby helping to increase food production and alleviate global hunger, said UCR plant biologist Long Jiang, who co-led the study.
Aluminum is the third most abundant element in the Earth’s crust, and highly acidic soils containing aluminum are widespread in many parts of the world. Acidic soils can result from natural weathering, and can be exacerbated by human activities, such as the overuse of nitrogen fertilizers.
The toxic effects of aluminum on plants are well documented, including stunted root growth, reduced water and nutrient uptake, and inhibition of cell division and expansion. These effects can severely impact crop yields and quality, posing significant challenges to global food security.
Despite the prevalence and impact of soil aluminum toxicity, the molecular mechanisms underlying aluminum tolerance in plants are not well understood. To address this knowledge gap, Jiang and his team set out to investigate how Arabidopsis plants respond to aluminum stress.
Using a genetic screening approach, the researchers identified a single gene, designated as ART1 (ALUMINUM RESPONSE TRANSCRIPTION FACTOR 1), that plays a crucial role in aluminum tolerance. ART1 encodes a transcription factor, a protein that regulates the expression of other genes.
The researchers found that a single mutation in the ART1 gene led to increased tolerance to aluminum stress in Arabidopsis plants. Roots of mutant plants displayed normal growth and development even in highly acidic soil, in contrast to the stunted roots of wild-type plants.
Further experiments revealed that ART1 regulates the expression of multiple genes involved in aluminum detoxification, root development, and cellular homeostasis. By altering the expression of these genes, ART1 helps plants to cope with aluminum stress and maintain root growth.
“Our findings provide new insights into the molecular mechanisms of aluminum tolerance in plants,” said Jiang. “By manipulating ART1 activity, it may be possible to develop crops with enhanced tolerance to acidic soils, which could have a significant impact on food production and global food security.”
The study was supported by grants from the National Science Foundation, the U.S. Department of Agriculture, and the China Scholarship Council.
