Saturday, May 23, 2026

Less fertilizer through smart alliances

New study identifies key switch controlling symbiosis

Leibniz Instiute of Plant Biochemistry

image:
Microscopic image of arbuscular mycorrhizal structures within the root cortex cells of Lotus japonicus. Photo: Kiran Raj, IPB
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Credit: Modified from Raj, K., Gaugler, V. et al. Lotus japonicus VIH2 is an inositol pyrophosphate synthase that regulates arbuscular mycorrhiza. Science Advances (2026). Leibniz Institute of Plant Biochemistry, IPB

Over the course of evolution, plants have developed an elegant strategy to counteract a lack of phosphate in the soil — they form symbiotic relationships with soil fungi. These mycorrhizal fungi efficiently supply their plant partners with phosphate and other essential minerals. Recently, scientists at the Leibniz Institute of Plant Biochemistry (IPB) in Halle, in collaboration with partners at the University of Bonn, discovered a molecular switch that detects the plant's phosphate content and signals whether to initiate or inhibit the symbiosis. This signaling pathway could enable plants to form partnerships with soil fungi even when sufficient phosphate is available. The study, published in the renowned journal Science Advances, offers a potential solution to a long-standing agricultural problem and opens new avenues for reducing fertilizer use.

Inoculating crops with mycorrhizal fungi is crucial for increasing agricultural yields. The fine fungal hyphae act like an extended root system, significantly increasing the uptake of minerals and nutrients. Phosphate is particularly vital for plants as it is a key regulator of their energy balance, and they efficiently extract it from the soil through this symbiosis. However, this partnership comes at a cost for plants: they must cede a portion of the carbohydrates they produce to the fungi. "This cost is so high for the plant that it suppresses the symbiosis when sufficient phosphate is available in the soil," explains Martina Ried-Lasi, head of the Symbiosis Signaling research group at the IPB. Despite an adequate phosphate supply, foregoing the symbiosis negatively impacts yields because the fungi also promote the uptake of nitrogen, magnesium, and potassium. "Therefore, agriculture is seeking strategies to maintain mycorrhizal associations in crops regardless of soil phosphate availability," says Gabriel Schaaf of the University of Bonn. "Our study demonstrates a potential approach for specifically promoting such symbioses in the future."

Using the model plant Lotus japonicus, the research team identified the enzyme VIH2 as a key regulator of symbiosis formation. VIH2 controls the production of inositol pyrophosphates, which are signal molecules that indicate phosphate status. When there is little phosphate in the cell, VIH2 produces low amounts of inositol pyrophosphates, signaling the cell to initiate a starvation program. This response includes activating phosphate-deficiency genes, remodeling root architecture, and initiating mycorrhizal symbiosis. When the phosphate supply is adequate, VIH2 produces large amounts of these signaling molecules. Accordingly, the phosphate starvation response is suppressed, and the partnership with mycorrhizal fungi is inhibited.

"We investigated whether a targeted inhibition of the enzyme would restart the phosphate starvation response and enable mycorrhiza formation," reports Martina Ried-Lasi. "And indeed, the plants behaved as if they were suffering from phosphate deficiency, even though sufficient phosphate was present in the culture medium." Consequently, the plants maintained their intensive colonization by mycorrhizal fungi, which are normally suppressed under the given phosphate conditions. The research team's most important finding: The sustained symbiosis had no negative effects on the growth and development of either partner under the experimental conditions studied. The fungal structures in the roots remained stable and functional, and the plants showed increased uptake of phosphate and other nutrients. "This allowed us to decouple the regulation of mycorrhizal symbiosis from the soil's phosphate status," says Gabriel Schaaf. "This has been a central goal in mycorrhiza research for decades."

With VIH2, plant experts have identified a key regulatory switch that controls the establishment of the symbiosis. This could enable the targeted manipulation of mycorrhization in crop plants in the future. Unlike conventional approaches, modern breeding methods such as genome editing can optimize the plant’s readiness for symbiosis flexibly and rapidly. However, it remains to be tested whether the effects on yield and stability can also be confirmed under field conditions. Nevertheless, this study introduces a new conceptual model that links phosphate perception in plants directly to the regulation of symbiotic relationships.

Phosphorus, in the form of phosphate, plays a central role in the energy metabolism of all living organisms. Phosphate is considered a limited, non-renewable resource. Additionally, many raw phosphate deposits are contaminated with heavy metals. Approximately 90 percent of the 200 million tons of raw phosphate mined worldwide each year is used to produce fertilizers. Without fertilizers, high-yield crop cultivation would not be possible. However, the excessive use of phosphate and mineral fertilizers leads to environmental problems such as soil contamination with heavy metals, groundwater pollution, and the eutrophication of aquatic ecosystems. Mycorrhization of crops is crucial for mitigating the phosphate problem in agriculture. With the help of these fungi in the soil, farmers can reduce their use of mineral fertilizers while lowering the risk of eutrophication.

Funding:
The work was funded by the German Research Foundation (DFG), including as part of the Transregio Collaborative Research Center TRR356 (IPB Halle) and the PhenoRob Cluster of Excellence at the University of Bonn.

Publication:
Raj, K., Gaugler, V. et al. Lotus japonicus VIH2 is an inositol pyrophosphate synthase that regulates arbuscular mycorrhiza. Science Advances (2026). https://doi.org/10.1126/sciadv.aec5607

Lotus japonicus, the model plant for mycorrhizal symbiosis. Photo: Elena Roitsch, IPB

Credit

Leibniz Institute of Plant Biochemistry, IPB

Journal

Science Advances

DOI

10.1126/sciadv.aec5607

Method of Research

Experimental study

Subject of Research

Cells

Article Title

Lotus japonicus VIH2 is an inositol pyrophosphate synthase that regulates arbuscular mycorrhiza.

Article Publication Date

22-May-2026

New Worcester Polytechnic Institute research could give used electric vehicle batteries a second life as higher-performance materials

$1 million Department of Energy-supported project builds on WPI’s leadership in battery recycling research and aims to strengthen U.S. battery supply chains, lower recycling costs, and improve sustainability for the electric vehicle industry

Worcester Polytechnic Institute

WPI Researchers develop new EV battery upcycling process — image:
WPI resarchers are recovering materials and upgrading them into higher-performance components that can directly support the next generation EV batteries.
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Credit: Worcester Polytechnic Institute

As demand for electric vehicles and energy storage systems accelerates worldwide, researchers at Worcester Polytechnic Institute (WPI) are developing a new approach to lithium-ion battery recycling that could help transform how critical battery materials are recovered, reused, and returned to the manufacturing pipeline.

Supported by a $1 million award from the U.S. Department of Energy, the project, led by Professor Yan Wang, William B. Smith Professor of Mechanical and Materials Engineering, will develop a one-step molten salt upcycling process that transforms spent nickel cathodes into high-performance material for next-generation lithium-ion batteries. The approach would reduce the cost, complexity, and energy demands of current battery recycling methods while increasing the value of recovered materials.

“Lithium-ion batteries are essential to the future of transportation, renewable energy, and modern technology, but the rapid growth of battery use also creates an urgent need for more sustainable and economically viable recycling solutions,” said Wang. “This project focuses not just on recovering materials, but on upgrading them into higher-performance battery components that can directly support the next generation of electric vehicles.”

After battery discharge, shredding. or dismantling, and separation of cathode and anode components, the team’s process converts mixed spent nickel-lean cathode materials into nickel-rich single-crystal cathodes such as NMC622, a necessary component in many of today’s lithium-ion batteries. Nickel oxide, manganese oxide, and cobalt oxide are used as source materials to upgrade blended cathode waste into advanced battery materials with improved capacity and stability compared to conventional commercial materials.

Designed to work with both pure and mixed cathode waste, the process eliminates additional sorting and separation requirements. The project also addresses a growing challenge within the battery industry: the mismatch between the materials recovered from older batteries and the newer high-performance materials needed for modern electric vehicle batteries.

“This work supports the development of a more circular battery economy,” Wang said. “Instead of treating spent batteries as waste, we are finding ways to convert them into materials that may perform even better than the originals. That has important implications for sustainability, manufacturing resilience, and the future competitiveness of the U.S. battery industry.”

The project builds on years of pioneering battery recycling and materials research led by Wang, whose work has focused on developing more sustainable and economically viable solutions for recovering and reusing lithium-ion battery materials. Wang’s research has advanced novel approaches for direct recycling and upcycling of battery waste, helping position WPI as a leader in next-generation battery sustainability and circular manufacturing technologies.

DNA reveals hidden biodiversity loss in Ontario streams, offering powerful new tool for freshwater monitoring

Groundbreaking Canadian study finds eDNA metabarcoding dramatically outperforms traditional methods in detecting ecological impacts of agriculture and urbanization

Hajibabaei Lab, University of Guelph

Hajibabaei lab researchers — image:
Led by Dr. Mehrdad Hajibabaei, the Hajibabaei lab is part of the Department of Integrative Biology in the College of Biological Science, University of Guelph. The lab is based in the Centre for Biodiversity Genomics.

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Credit: Hajibabaei lab

Researchers using cutting-edge environmental DNA (eDNA) technology have uncovered far greater biodiversity in eastern Ontario waterways than traditional monitoring methods detected over more than a decade, demonstrating the transformative potential of DNA-based biomonitoring for freshwater conservation and environmental management.

The study, published in the journal Molecular Ecology, analyzed benthic macroinvertebrates, small aquatic organisms such as insect larvae, crustaceans, and other stream-dwelling species widely regarded as key indicators of freshwater ecosystem health, across 18 streams in the agriculturally dominated South Nation River watershed in eastern Ontario. Environmental DNA researchers found that a single year of DNA metabarcoding identified dramatically more biodiversity than conventional surveys, while also revealing much clearer ecological signals linked to agriculture, water quality, and land use, based on morphology-based data for 10 years gathered within a span of 15 years.

“This study shows that DNA metabarcoding can reveal ecological patterns and biodiversity changes that traditional approaches often miss,” said senior author Mehrdad Hajibabaei. “The ability to rapidly and accurately detect species-level changes across freshwater systems could fundamentally improve how we monitor, manage, and protect aquatic ecosystems under increasing environmental stress.”

The findings come as freshwater ecosystems worldwide face mounting pressures from agricultural intensification, urban expansion, pollution, and climate change. Agriculture alone occupies more than 37 per cent of Earth’s terrestrial surface and is considered one of the leading drivers of biodiversity decline globally.

The South Nation River watershed, covering approximately 3,900 square kilometres in eastern Ontario, provided an ideal test case. The region contains a complex mix of agricultural lands, forests, and expanding urban areas, much of it heavily influenced by extensive subsurface tile drainage systems used to support intensive farming.

To conduct the study, researchers collected benthic macroinvertebrate samples during summer and fall 2023 from streams spanning a gradient from predominantly forested to heavily agricultural landscapes. Using DNA metabarcoding, they extracted and sequenced genetic material from bulk environmental samples, enabling the identification of hundreds of species simultaneously through high-throughput sequencing technologies.

The results revealed striking differences between the DNA-based and traditional monitoring approaches.

DNA metabarcoding detected 282 species across the watershed, with 261 species found exclusively through the DNA approach. Traditional morphology-based methods detected only 22 unique species not recovered by DNA analysis, while just 20 species overlapped between both methods.

At the site level, DNA metabarcoding recovered significantly more species and orders than morphology-based identification. Median species richness per site was 59 species using DNA compared to just 15 using conventional methods.

The DNA analyses also uncovered extensive hidden diversity. Nearly 44 per cent of detected species occurred at only a single site, suggesting many freshwater species may have highly localized distributions that conventional methods fail to capture.

Importantly, the DNA-based approach provided far sharper ecological resolution. Statistical analyses showed that DNA metabarcoding consistently distinguished differences between agricultural, forested, and mixed-use stream systems more clearly than historical morphology datasets collected over many years.

Agricultural streams displayed strong associations with elevated conductivity, turbidity, and altered pH levels, indicators linked to fertilizer runoff, soil disturbance, and intensive land management. Forested streams, by contrast, were associated with higher dissolved oxygen levels and greater biodiversity.

“Even relatively modest changes in community composition can provide important early warning signals of ecosystem stress,” the authors wrote. “DNA metabarcoding offers the sensitivity needed to detect these changes before larger ecological degradation becomes apparent.”

The study also highlights longstanding limitations of traditional morphology-based biomonitoring. While Ontario’s widely used Ontario Benthos Biomonitoring Network protocol has provided valuable stream assessments for years, the method relies heavily on expert taxonomic identification, which can be slow, labour-intensive, and often incapable of reliably distinguishing closely related or immature organisms.

Among nearly 80,000 specimens collected through conventional monitoring from 2008 to 2022, most remained unresolved at the species level. In many survey years, more than 90 per cent of specimens could not be confidently identified to species using morphology alone.

DNA metabarcoding, by contrast, rapidly generated fine-scale biodiversity data across multiple taxonomic levels and successfully identified numerous groups underrepresented or entirely absent in morphology-based records, including several insect and crustacean lineages.

Researchers say the technology could substantially strengthen long-term freshwater monitoring programs, particularly in regions experiencing mixed environmental stressors from agriculture and urbanization.

The study supports growing international momentum toward integrating eDNA approaches into routine environmental assessment programs. Because DNA metabarcoding requires less dependence on specialized taxonomic expertise while offering faster processing and greater reproducibility, it may help agencies scale up monitoring efforts at lower cost and with higher ecological sensitivity.

The authors emphasize that traditional methods still retain value, especially for historical continuity and certain trait-based analyses. However, they argue that DNA metabarcoding should now become a core component of modern freshwater biomonitoring frameworks.

“The future of freshwater biomonitoring will likely combine rapid, scalable DNA-based screening with targeted traditional surveys where needed,” the researchers concluded. “This integrated approach offers a more sensitive, timely, and comprehensive understanding of ecological change in freshwater ecosystems facing accelerating human pressures.”

With study was led by the Hajibabaei lab at the Centre for Biodiversity Genomics and the Department of Integrative Biology at the University of Guelph with collaborators from AAFC and South Nation Conservation.

“Fine-Scale Ecological Biomonitoring in a Large, Complex Agriculturally Impacted Watershed via eDNA Metabarcoding,” was authored by Bráulio S. M. L. Silva, Andrew C. Riley, Emilia Craiovan, Michael Wright, Katherine Watson, David R. Lapen, and Mehrdad Hajibabaei and published in Molecular Ecology. Funding was provided by the New Frontiers in Research Fund, the Illumina Foundation, Environment and Climate Change Canada, and the Canadian Safety and Security Program.

The Hajibabaei lab conducts research on biodiversity, ecosystems and environmental change by investigating evolutionary processes at the genomic level and the use of sequence information. Its work spans from molecular evolutionary biology to technology development and bioinformatics.