Researchers at the University of Toronto have uncovered how plants communicate with fungi, a discovery that could reshape agricultural practices. The study, published in Molecular Cell, reveals how the plant hormone strigolactone (SL) activates fungal genes linked to phosphate metabolism, which is vital for growth. This breakthrough could lead to stronger crops and new methods for combating harmful fungi.
Key Discovery in Plant-Fungi Communication
The research team, led by Shelley Lumba, assistant professor of cell and systems biology, used baker’s yeast to decode how fungi respond to chemical signals from plants. Lumba explains that understanding this interaction can improve agricultural biodiversity and crop health. “This insight into plant and fungi communication can help us cultivate healthier crops and promote ecosystem biodiversity,” said Lumba.
In the soil, plants and fungi interact in a symbiotic relationship. Plants release SLs, signaling fungi to attach to their roots, exchanging phosphates—essential for plant growth—for carbon. Phosphates, a major component of fertilizers, fuel plant development.
Improving Crop Resilience and Reducing Fertilizer Dependence
Eighty percent of plants depend on fungi for survival, making this relationship crucial for agriculture. Enhancing the interaction with beneficial fungi could lead to more resilient crops, reducing the need for fertilizers and minimizing environmental damage from phosphate runoff.
However, not all fungi are beneficial. Some, like wheat blight, exploit these signals to infect crops. By understanding this chemical language, scientists hope to block harmful fungi from damaging harvests.
Using Yeast to Decode Fungal Responses
Due to the complexity of the soil environment, it was previously difficult for scientists to pinpoint how these chemical signals affect fungi. Lumba’s team cracked this code using baker’s yeast, a simpler fungus that has been domesticated for thousands of years. Yeast’s stable nature made it ideal for lab studies.
The researchers treated yeast with SLs and observed how the fungus responded. They found that SLs activated genes related to phosphate metabolism, known as “PHO” genes. Further investigation revealed that SLs function through Pho84, a protein on the yeast’s surface that monitors phosphate levels. This protein triggers a chain reaction affecting phosphate uptake.
Plants release SLs when they are low on phosphate, signaling fungi to adjust their phosphate absorption.
Broad Implications for Agriculture
The study’s findings apply not only to domesticated fungi like baker’s yeast but also to wild fungi. Researchers tested the effects on the wheat blight fungus Fusarium graminearum and the beneficial fungus Serendipita indica, and the results were consistent. Both types of fungi responded to the SL signal by adjusting phosphate metabolism.
“This method is key to understanding how SLs affect fungal growth,” said Lumba. The team’s approach provides a systematic way to identify small plant molecules that communicate with fungi. This could lead to agricultural advances, helping farmers boost crop resilience while reducing fertilizer use and pollution.
A Step Toward Sustainable Agriculture
Lumba believes this discovery has far-reaching implications. “This research can improve lives by promoting healthier soil and a healthier planet,” she said. By enhancing our understanding of plant-fungi interactions, scientists may develop strategies to increase food security and mitigate environmental challenges.
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