Soil or seed inoculation with beneficial microbes or symbionts is a promising strategy to improve crop yield without relying on chemical fertilizers.
Decades of research into the microbiome, symbiosis and mechanisms of plant–microbe associations more generally have helped, but there are still challenges ahead.
One limitation is the weak survival of suddenly transplanted bacteria or fungi, which must compete against the well-adapted indigenous microbiome.
Finally, when seedlings exposed to salt stress were inoculated with capsules containing specific non-sporulating beneficial bacteria, growth increased significantly across several crop species.
The little spherical shields prolonged bacterial survival and enhanced plant protection.
Soil or seed inoculation with beneficial microbes or symbionts is a promising strategy to improve crop yield without relying on chemical fertilizers. Decades of research into the microbiome, symbiosis and mechanisms of plant–microbe associations more generally have helped, but there are still challenges ahead. One limitation is the weak survival of suddenly transplanted bacteria or fungi, which must compete against the well-adapted indigenous microbiome. In addition, desiccation, heat, ultraviolet radiation and other stresses can also compromise inoculants, including during storage and transport.
To address these issues, Xu and colleagues designed microcapsules composed of three naturally derived polymers: sodium alginate, polyglutamic acid and chitosan, which form a complex gel structure when cross-linked with calcium. After some optimization, the capsules were mixed with bacteria and their protective effect was validated. Proteomic analyses revealed that the bacteria entered a dormancy-like state, characterized by reduced energy metabolism. Finally, when seedlings exposed to salt stress were inoculated with capsules containing specific non-sporulating beneficial bacteria, growth increased significantly across several crop species. The little spherical shields prolonged bacterial survival and enhanced plant protection. By imitating a bacterial spore, the researchers found a way to protect the protectors.
