Beneath the surface lies one of nature's most remarkable partnerships—a hidden network of fungi that forms symbiotic relationships with plant roots.
Beneath the surface of every forest, grassland, and agricultural field lies one of nature's most remarkable partnerships—a hidden network of fungi that forms symbiotic relationships with plant roots. These mycorrhizal fungi serve as nature's internet, connecting plants in sophisticated networks that exchange nutrients, water, and information. In China, where food security and environmental conservation are national priorities, scientists are leading cutting-edge research to understand and harness these fungal networks. From the saline-alkaline soils that challenge agriculture to the urban landscapes transforming ecosystems, Chinese researchers are uncovering how these microscopic alliances can help address some of our most pressing environmental challenges. Their work is revealing an underground world far more complex and vital than we ever imagined.
Mycorrhizal fungi represent one of the most widespread and ancient plant-fungal partnerships on Earth, with fossil evidence showing they existed over 450 million years ago. The term "mycorrhiza" literally means "fungus-root" and describes the mutually beneficial relationship between these specialized fungi and the roots of most terrestrial plants. The plant provides the fungus with carbohydrates produced through photosynthesis, while the fungus dramatically expands the plant's root system with its extensive hyphal networks, sometimes extending hundreds of meters to absorb water and essential nutrients like phosphorus and nitrogen.
Scientists recognize several types of mycorrhizal associations, each with distinct characteristics and plant preferences. These include Arbuscular Mycorrhizal Fungi (AMF), Ectomycorrhizal Fungi (EcM), and Ericoid Mycorrhizal Fungi (ErM), each forming unique relationships with different plant species and providing specialized benefits.
| Feature | Arbuscular Mycorrhizal (AM) | Ectomycorrhizal (EcM) | Ericoid Mycorrhizal (ErM) |
|---|---|---|---|
| Plant Partners | ~71% of angiosperms, most crops | ~2% of plants, mostly trees | ~1.5% of plants, heath family |
| Fungal Taxonomy | Monophyletic (Glomeromycota) | Polyphyletic (multiple fungal groups) | Polyphyletic (multiple fungal groups) |
| Infection Structure | Penetrates root cells | Forms sheath around roots | Forms coils in root cells |
| Nutrient Access | Inorganic nutrients only | Inorganic & organic nutrients | Specialized for organic nutrient access |
| Global Carbon Storage | 240 GT in aboveground plant biomass | 100 GT in aboveground plant biomass | 7 GT in aboveground plant biomass |
A groundbreaking 2025 global study published in Nature has dramatically advanced our understanding of mycorrhizal distribution worldwide. By training machine-learning algorithms on a massive dataset of 25,000 geolocated soil samples containing over 2.8 billion fungal DNA sequences, an international research team created the first high-resolution global maps of mycorrhizal diversity 1 .
AM fungi follow the classical latitudinal diversity gradient, with richness highest at the equator and gradually declining toward the poles 1 .
EcM fungi show an inverse pattern, with lowest diversity near the equator and peak richness in northern latitudes and southern regions of South America and Australia 1 .
The study identified critical hotspots for mycorrhizal conservation, including the Brazilian Cerrado savannas, Southeast Asian tropical forests, and Guinean forests in West Africa for AM fungi.
25,000 geolocated soil samples collected worldwide
2.8 billion fungal DNA sequences analyzed
Algorithms trained to map mycorrhizal diversity
Global distribution patterns revealed for different mycorrhizal types
With approximately 99.13 million hectares of salinized soil—including significant saline-alkaline land in Xinjiang accounting for 22.01% of the country's total—China faces substantial agricultural challenges 3 . Saline stress immobilizes soil nutrients and inhibits microbial activity, reducing soybean yields by 24-65% when soil conductivity exceeds specific thresholds. Addressing this problem is crucial for China's food security.
Researchers from Shihezi University and Yangtze University designed an elegant pot experiment to test whether AM fungi could help soybeans withstand saline-alkaline stress while reducing phosphorus fertilizer requirements 3 .
The results demonstrated remarkable benefits from the fungal partnership:
| Parameter | Non-inoculated (P50) | AMF-inoculated (P50) | Change (%) |
|---|---|---|---|
| Soil Available P (mg·kg⁻¹) | Baseline | +23.11% | +23.11% |
| Leaf P Content (mg·g⁻¹) | 2.38 | 4.72 | +98.50% |
| Stem P Transport Rate (%) | Not reported | 37.27% | - |
| Root Fresh Weight (g) | Lower than peak | Reached peak at P50 | More efficient |
Data from soybean salinity stress experiment 3
Mycorrhizal research requires specialized materials and methodologies to unravel the complexities of these hidden relationships. The following table details key reagents and their applications in typical experiments, based on methods from recent studies 3 5 .
| Reagent/Material | Function/Application | Example from Research |
|---|---|---|
| AMF Inoculum | Establishing symbiotic relationships in experiments | Mixed species: Funneliformis mosseae, Rhizophagus intraradices, Diversispora epigaea 3 |
| DNA Extraction Kits | Isolating fungal DNA from soil samples | Fast DNA SPIN for Soil Kit (MP Biomedicals) |
| PCR Primers | Amplifying specific fungal DNA regions for identification | ITS1F & ITS2R for fungal ITS region |
| Sterilized Growth Media | Providing consistent, contaminant-free plant growth environment | Autoclaved soil (115 kPa, 121°C for 2 hours) 3 |
| Saline Stress Solution | Mimicking natural saline-alkaline soil conditions | NaCl, Na₂SO₄, NaHCO₃, Na₂CO₃ (12:9:8:1 ratio) 3 |
| Reference Databases | Taxonomic classification of sequenced fungi | UNITE v8.0 database for fungal identification |
Chinese research extends beyond agricultural applications to address broader environmental challenges. A compelling 2025 study in Shenzhen—a city that transformed from a small village to a megacity in just 30 years—examined how rapid urbanization affects soil fungal communities .
The research revealed that urban areas had significantly lower fungal diversity than natural ecosystems, with streets showing the lowest phylogenetic diversity. This decline was linked to higher phosphorus content in urban soils creating nutrient imbalances .
Interestingly, while fungal communities shifted dramatically within the first decade of urbanization, they gradually transitioned to a new consistent state in subsequent decades, demonstrating a capacity to adapt to urban conditions .
Concurrently, Chinese researchers are exploring how mycorrhizal fungi can enhance forest carbon sequestration and ecosystem restoration. Mycorrhizal associations play crucial roles in soil carbon storage through multiple mechanisms: stabilizing soil aggregates, producing organic compounds that bind soil particles, and allocating carbon belowground 4 5 . These functions are increasingly important in China's ambitious reforestation and ecological restoration programs.
As Chinese scientists continue to decode the complexities of mycorrhizal networks, several promising research directions are emerging:
Developing tailored fungal inoculants for specific crop varieties and soil conditions to optimize agricultural benefits while reducing chemical inputs 3 .
Using predictive modeling to identify and protect underground biodiversity hotspots, recognizing that mycorrhizal diversity doesn't always align with visible plant diversity 1 .
Integrating fungal community considerations into urban planning and green space management to maintain soil health in cities .
The silent underground alliance between plants and mycorrhizal fungi has sustained terrestrial ecosystems for millions of years. Today, Chinese researchers are illuminating these hidden networks with unprecedented clarity, revealing their potential to address some of our most pressing agricultural and environmental challenges. From the saline soils of Xinjiang to the rapidly urbanizing landscapes of Shenzhen, this research demonstrates that understanding and nurturing these microscopic partnerships offers powerful pathways toward more sustainable agriculture, healthier ecosystems, and enhanced carbon storage.
As we face the interconnected challenges of climate change, food security, and biodiversity loss, the humble mycorrhizal fungus reminds us that in nature—as in science—collaboration and connection create resilience. By learning from these ancient underground networks, we might just cultivate a more sustainable future above ground.