|KIM, DA-RAN - Gyeongsang National University|
|CHO, GYEONGJUN - Gyeongsang National University|
|JEON, CHANG-WOOK - Gyeongsang National University|
|KWAK, YOUN-SIG - Gyeongsang National University|
Submitted to: Nature Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2019
Publication Date: 10/22/2019
Citation: Kim, D., Cho, G., Jeon, C., Weller, D.M., Thomashow, L.S., Kwak, Y. 2019. A mutualistic interaction between Streptomyces bacteria, strawberry plants and pollinating bees. Nature Communications. 10,4802. https://doi.org/10.1038/s41467-019-12785-3.
Interpretive Summary: Beneficial bacteria colonize plant surfaces both above and below ground. The soil is the source of many of these bacteria, but how they become established on above-ground plant parts is poorly understood. In this study, we tracked the movement of a beneficial strain of Streptomyces bacteria that can grow in the interior of plant parts through a greenhouse in which strawberries are grown. We found genetically identical isolates of the bacteria on the roots and the flowers, although the habitats were separated in space and time. The strain on roots moved upward inside the plant tissues, relocated to the flowers, and protected the plants against a fungal pathogen. It also moved downward onto the roots, and among flowers via bees that were protected against insect pathogens by the bacteria. The results reveal a novel beneficial interaction in which the bacteria benefit both the plant and the insect.
Technical Abstract: Microbe-plant interactions include mutualistic relationships upon which plants and their microbiota depend to thrive in nature. However, why and how the microbiota of belowground plant parts become established aboveground is poorly understood. We tracked the movement of a probiotic Streptomyces endophyte throughout a managed strawberry ecosystem. Probiotics in the rhizosphere and anthosphere were identical at the genome level, yet these niches were segregated in space and time. The probiotic in the rhizosphere moved upward via the vascular bundle, relocated to aboveground plant parts, and protected against Botrytis cinerea. It also moved downward into the rhizosphere and among flowers via pollinators, which were protected. against insect pathogens. Our results reveal a novel mutualism with Streptomyces exploiting the plant and an insect partner.