Researchers have uncovered a biological mechanism that makes plant roots more inviting to helpful soil microbes.
Researchers have uncovered a biological mechanism that makes plant roots more inviting to helpful soil microbes.
This finding from the John Innes Centre researchers could lead to more eco-friendly agricultural practices, potentially enabling farmers to cut back on fertilizer use.
The growth of most major crops depends on nitrate and phosphate fertilizers, but their overuse poses risks to the environment.
If we could leverage the mutually beneficial relationships between plant roots and soil microbes to improve nutrient absorption, we might be able to lessen our reliance on synthetic fertilizers.
A team led by Dr. Myriam Charpentier identified a mutation in a gene within the legume Medicago truncatula that reconfigures the plant’s signaling capacity, thereby strengthening its partnerships with nitrogen-fixing bacteria known as rhizobia and arbuscular mycorrhiza fungi (AMF), which provide phosphorus to the roots.
This type of partnership, termed endosymbiosis, occurs when one organism lives inside another and allows legumes to capture nutrients from the soil through microbes in exchange for sugars.
A significant challenge to the widespread adoption of endosymbiotic partnerships in farming is their tendency to thrive in nutrient-poor soils, which clashes with the intensive farming practices in use today.
In a study published in Nature, experiments revealed that the gene mutation affecting a calcium signaling pathway improves endosymbiosis even under farming conditions.
Excitingly, the research team also demonstrated that this same gene mutation boosts colonization by nitrogen-fixing bacteria and AMF in wheat when grown in fields.
This discovery marks a significant advancement in the quest to utilize enhanced endosymbiotic relationships as a natural substitute for synthetic fertilizers across key crops, including cereals and legumes.
“Our findings offer great promise for promoting sustainable agriculture. It is both unexpected and thrilling that the mutation we identified enhances endosymbiosis in farming contexts, as it opens doors for sustainable crop production using endosymbionts while reducing the need for inorganic fertilizers,” Dr. Charpentier commented.
“This discovery not only contributes broadly to the understanding of calcium signaling but also provides a pathway toward more sustainable production of economically vital crops.”
Prior research by Dr. Charpentier’s team has shown that calcium signaling in root cell nuclei is crucial for establishing root endosymbiosis with beneficial nitrogen-fixing bacteria and AMF.
This study elucidates that fundamental signaling mechanism, detailing how calcium fluctuations regulate the production of compounds known as flavonoids, which enhance endosymbiosis.
“Our discovery highlights the critical role of foundational science in tackling societal issues,” Dr. Charpentier concluded.
Root endosymbiosis provides substantial benefits to plants by boosting nutrient absorption and stress resilience. There is a growing demand for the development of high-yield, disease-resistant crops while minimizing fertilizer use to safeguard the environment and lower farmers’ costs.
Integrating disease resistance and climate resilience with effective nutrient absorption through improved relationships with symbiotic microorganisms is essential to this goal.
