Clay Mineral Montmorillonite Found to Enter Plant Roots via Lateral Root Junctions

A New Pathway for Plant Nutrition: The Discovery of Direct Clay Uptake

A groundbreaking study has revealed that plants can absorb clay particles directly through their roots, a discovery that challenges long-held views on plant nutrition and soil interaction.

Led by researchers from the Chinese Academy of Sciences and Qingdao University, the study tracked fluorescently labeled montmorillonite particles in wheat plants. The findings, published in Pedosphere in March 2025, show that these particles enter the root system through a specific, previously overlooked route.

"This study fundamentally shifts our view of how plants interact with their soil environment." — Dr. Yongming Luo, senior author

Particles entered roots through natural fissures at lateral root junctions, effectively bypassing the Casparian strip—a key barrier that was previously thought to block such large particles.

Researchers used a multi-pronged imaging approach, including confocal microscopy, SEM, TEM, and AFM-IR spectroscopy, to track the particles' journey.

• The particles were detected in root vascular tissues just 24 hours after application, with fluorescence signals intensifying over time.
• The analysis confirmed the presence of montmorillonite particles in the stems and leaves of the wheat plants.
• Crucially, the study found that the clay particles carried essential nutrients (K, Ca, Fe) and became coated with organic coronas, a process that may facilitate their transport and integration within the plant.

This discovery reveals a previously unknown mechanism for how plants might access minerals from the soil. In environments where soils are depleted, this process could be vital.

Dr. Luo added that the discovery reveals a hidden route for nutrient delivery and provides a foundation for future research.

The findings have significant implications for global food security, particularly for staple crops like wheat and rice that are grown in nutrient-poor soils.

• Crops may directly utilize clay particles as alternative nutrient sources, offering a natural buffer against soil depletion.
• The research could inform the design of nano-enabled fertilizers or soil amendments that mimic this natural mineral uptake process.

By understanding how plants naturally interact with clay minerals, scientists may develop more efficient and sustainable ways to deliver essential nutrients to crops, reducing the need for traditional chemical fertilizers.