Biochemical controls: controlling plant fungus symbiosis (Introduction)

by David Turell , Tuesday, April 15, 2025, 21:07 (3 days ago) @ David Turell

Improving it:

https://www.sciencedaily.com/releases/2025/04/250414162051.htm

"Scientists use small peptides to enhance symbiosis between plants and fungi, offering a sustainable alternative to artificial fertilizers. Plant biologists discover new plant molecule, CLE16, as well as a fungal CLE16 mimic, that encourage the beneficial symbiotic relationship between plants and fungi. CLE16 supplementation in crop fields could help reduce harmful chemical fertilizer use by replacing it with sustainable, long-lasting symbiotic plant-fungus relationships for important crops like soy, corn, and wheat.

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"In a new study, the researchers identified a key molecule produced by plant roots, a small peptide called CLE16, that encourages plants and beneficial soil fungi to interact with each other. They say boosting this symbiotic relationship, in which the fungi provide mineral nutrients to the plants through CLE16 supplementation, could be a more natural and sustainable way to encourage crop growth without the use of harmful artificial fertilizers.

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"'By restoring the natural symbiosis between plant roots and fungi, we could help crops get the nutrients they need without the use of harmful fertilizers."

"In this mutually beneficial relationship, soil-borne arbuscular mycorrhizal fungi supply plants with water and phosphorus, which the plants accept in exchange for carbon molecules. These exchanges occur by specialized symbiotic fungal tendrils, called arbuscules, burying themselves into plant root cells. Around 80% of plants can trade resources with fungi in this way. However, the traits that support this symbiosis have been weakened over centuries of agricultural plant breeding that prioritized creating crops with the biggest yields.

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"To begin discovering and strengthening these traits, Mueller's lab started by growing a species of arbuscular mycorrhizal fungus together with Medicago truncatula, a small Mediterranean legume. Once the two had formed a symbiotic relationship, the researchers looked to see what genes were supporting this interaction.

"The legumes had started to express large amounts of a small signaling molecule called CLE16 -- a member of the CLE family of peptides. These small signaling molecules are present in many plant species yet have been relatively understudied. Until CLE16, the only plant CLE peptides scientists had studied were working against symbiosis.

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"To confirm that CLE16 was promoting the symbiotic relationship, Bashyal added excess CLE16 to the soil to see what would happen. The extra dose of CLE16 caused the fungal arbuscules to become more robust and live longer, ultimately increasing the abundance of these nutrient-trading structures in the roots. The result was a self-amplifying pro-symbiosis signal: The more the beneficial fungus expanded inside the roots, the more CLE16 was produced by the plant, which then promoted even more fungal colonization.

"The team then did a series of experiments to understand how CLE16 was encouraging this interaction between plants and beneficial fungi. Their findings revealed that CLE16 promotes the symbiosis via the signaling protein CORYNE (CRN), a component of the CLAVATA receptor complex known for its roles in plant responses to the environment.

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"Mueller's team showed that many arbuscular mycorrhizal fungi also produce their own CLE16-like peptides, which also promoted symbiosis when added to the soil. The researchers think that these fungal peptides imitate the plants' own CLE16 peptides, thus enabling the beneficial fungus to amplify symbiosis by binding to the same plant CRN-CLAVATA receptor complexes."

Comment: symbiosis is always an advantage to help exchanges of nutrients.