Biochar and plant hormone team up to protect wheat from toxic metals and drought
image: Enhancing bread wheat resilience to cadmium and drought stress: insights from physiological, morphological, and transcriptomic responses to biochar and 24-epibrassinolide application
Credit: Fasih Ullah Haider, Noor-ul- Ain, Kadambot H. M. Siddique, Muhammad Farooq & Yuelin Li
A new study reveals that combining biochar with a natural plant hormone can significantly improve wheat’s ability to withstand two major agricultural threats: cadmium contamination and drought.
Cadmium is a toxic heavy metal that accumulates in soils due to industrial activity, fertilizers, and irrigation with polluted water. At the same time, drought stress is becoming more frequent under climate change. Together, these stresses reduce crop yields and can pose risks to food safety.
In research published in Biochar, scientists investigated how biochar, a carbon-rich material produced from biomass, works together with 24-epibrassinolide, a plant growth regulator, to protect wheat under these harsh conditions.
The team conducted controlled experiments exposing wheat plants to cadmium and drought stress. They then applied biochar to the soil and sprayed plants with the hormone to evaluate changes in growth, physiology, and gene expression.
The results were striking. Under stress conditions, wheat plants typically showed reduced growth, impaired photosynthesis, and increased oxidative damage. However, when biochar and the hormone were applied together, plant performance improved dramatically.
Root biomass, leaf area, and shoot biomass increased substantially, in some cases by more than 70 percent compared to untreated plants. At the same time, cadmium accumulation in leaves dropped sharply, indicating reduced uptake of the toxic metal.
“Our findings show that combining biochar with 24-epibrassinolide provides a powerful strategy to protect wheat from both drought and cadmium stress,” said one of the study’s corresponding authors. “This approach not only improves plant growth but also limits the entry of harmful metals into the food chain.”
The study also uncovered the biological mechanisms behind these benefits. Biochar improved soil conditions by enhancing water retention and immobilizing cadmium, making it less available for plant uptake. Meanwhile, the plant hormone activated defense systems inside the plant.
Measurements showed reduced levels of harmful reactive oxygen species and increased activity of antioxidant enzymes. These changes help protect plant cells from stress-induced damage.
At the molecular level, the researchers identified more than 6,000 genes whose activity changed in response to the combined treatment. Many of these genes are involved in detoxification, nutrient metabolism, and stress signaling pathways.
Key transcription factor families such as AP2/ERF, MYB, and WRKY were upregulated, indicating enhanced stress adaptation. Genes linked to photosynthesis and nitrogen uptake also showed increased expression, supporting improved plant performance.
Importantly, genes responsible for transporting heavy metals were downregulated, which aligns with the observed reduction in cadmium accumulation.
The researchers emphasize that this combined strategy offers a sustainable and practical solution for agriculture. Biochar can be produced from agricultural waste, making it both cost-effective and environmentally friendly. The use of plant hormones further enhances resilience without relying on harmful chemicals.
However, the authors note that additional field studies are needed to confirm these findings under real farming conditions and to assess long-term impacts.
Overall, the study provides new insights into how integrated soil amendments and plant regulators can work together to improve crop resilience in contaminated and water-limited environments.
As global food systems face increasing pressure from pollution and climate change, such strategies could play a key role in ensuring safe and stable crop production.
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Journal Reference: Haider, F.U., Ain, Nu., Siddique, K.H.M. et al. Enhancing bread wheat resilience to cadmium and drought stress: insights from physiological, morphological, and transcriptomic responses to biochar and 24-epibrassinolide application. Biochar 7, 59 (2025).
https://doi.org/10.1007/s42773-025-00457-z
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About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.