Foshan University pioneers nanoparticle method to curb cadmium in rice crops

Cadmium (Cd) pollution is an urgent global agricultural challenge, particularly in regions dependent on rice cultivation as a dietary staple. Even at low concentrations, Cd can move rapidly through the soil–crop–human pathway and accumulate in vital organs, leading to kidney damage, bone disorders, and increased cancer risk. As soil contamination continues to rise due to industrial activities and fertilizer overuse, identifying safe and scalable strategies to reduce heavy metal transfer into food crops is essential for future food security.

To tackle this challenge, a research team led by Dr. Lin Tao, with Dr. Xuecheng Sun, Dr. Fangbai Li, Dr. Min Yu, and colleagues at the International Research Center for Environmental Membrane Biology and the Department of Horticulture, Foshan University, Guangdong, China, examined how foliar-applied molybdenum nanoparticles (MoNPs) influence cadmium transport, cellular signaling, and detoxification responses in rice. Their findings demonstrate how MoNPs help protect plants from metal toxicity by altering both molecular pathways and biochemical defense systems. The study, made available online in The Crop Journal on October 23 2025, provides a new mechanistic understanding of nanoparticle-assisted stress alleviation in food crops.

“We discovered that foliar-sprayed MoNPs down-regulate key genes involved in cadmium uptake and cell wall modification, specifically those linked to Cd transport and pectin methyl-esterification,” says Tao. “This dual regulatory effect significantly reduces Cd accumulation in root tissues, limiting the amount that can eventually reach grains.”

“Our work shows that foliar MoNPs act at multiple regulatory levels to block the passage of toxic metals into edible plant organs,” says Yu. “This represents an efficient, scalable strategy to protect rice grown in contaminated soils.”

Beyond metal transport, the study focused on oxidative stress—a major consequence of Cd toxicity. Using detailed imaging, the team found that hydrogen peroxide and hydroxyl radicals, two reactive oxygen species (ROS) that trigger severe cellular injury, mainly accumulate in the elongation and mature zones of rice roots, especially at the connecting sites between neighboring cells. This precise spatial mapping advances fundamental knowledge on where and how oxidative damage initially forms in living roots.

Another key finding involved the regulation of respiratory burst oxidase homologs (RBOHs)—plasma membrane proteins responsible for ROS production. Under Cd stress, untreated rice plants showed an excessive RBOH buildup, creating dangerous ROS surges. MoNP application suppressed OsRBOHs gene expression, lowering RBOH localization at the plasma membrane and preventing destructive oxidative bursts. At the same time, MoNPs enhanced the ascorbate–glutathione (ASA–GSH) cycle, a core antioxidant defense pathway, improving the plant’s ability to neutralize ROS. “By stabilizing the plant’s oxidative environment, MoNPs support normal growth even when soil contaminants are present,” says Sun.

The potential agricultural benefits are promising. Foliar MoNP treatment offers farmers a practical, low-input solution that can be easily integrated into existing cultivation systems. By controlling Cd transport at the source, the plant’s root interface, this method reduces the movement of toxins into the food chain. In regions where soil cleanup is economically unfeasible, such innovations may help safeguard public health by lowering dietary Cd exposure.

Looking ahead, the research also lays foundational knowledge for nanotechnology-driven crop protection against multiple abiotic stresses. “The team’s work of mapping apoplastic ROS distribution along entire root apices provides an invaluable reference for scientists studying stress signaling under salinity, drought, or other environmental pressures,” says Tao. “The insights from this study could support a new generation of sustainable agronomic strategies designed to protect crop yields and ensure safer foods over the next 5–10 years.”

###

Media contact: Guangming Yang, Email address: yangguangming@caas.cn , Tel: +86-13683670916

The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).