Location: Molecular Plant Pathology LaboratoryTitle: Spatiotemporal dynamics and quantitative analysis of phytoplasmas in insect vectors
|KOINUMA, HIROAKI - University Of Tokyo
|MAEJIMA, KENSAKU - University Of Tokyo
|TOKUDA, RYOSUKE - University Of Tokyo
|KITAZAWA, YUGO - University Of Tokyo
|NIJO, TAKAMICHI - University Of Tokyo
|KUMITA, KOHEI - University Of Tokyo
|MIYAZAKI, AKIO - University Of Tokyo
|NAMBA, SHIGETOU - University Of Tokyo
|YAMAJI, YASUYUKI - University Of Tokyo
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2020
Publication Date: 3/9/2020
Citation: Koinuma, H., Maejima, K., Tokuda, R., Kitazawa, Y., Nijo, T., Wei, W., Kumita, K., Miyazaki, A., Namba, S., Yamaji, Y. 2020. Spatiotemporal dynamics and quantitative analysis of phytoplasmas in insect vectors. Scientific Reports. 10:1-13. https://doi.org/10.1038/s41598-020-61042-x.
Interpretive Summary: Phytoplasmas are a small group of cell wall-less bacteria, and transmitted from plants to plants by their insect vectors in a persistent-propagative manner. In this study, ARS scientist and collaborators employed immunohistochemistry-based 3D imaging visualization, whole-mount fluorescence staining, and real-time quantitative PCR and investigated spatiotemporal distribution and accumulation of onion yellows (OY) phytoplasma in its leafhopper vector. ARS scientist and collaborators successfully identified two major sites of phytoplasma infection, and proposed a model for spatiotemporal dynamics of phytoplasmas in insect vectors. The findings from this study will help understand the underlying mechanism of insect-borne plant pathogen transmission. The information is important to research scientists, students, and university professors who are studying pathogen-host interactions, insect-borne pathogen transmission, and disease management.
Technical Abstract: Phytoplasmas are transmitted by insect vectors in a persistent-propagative manner, however, detailed movement and replication patterns of phytoplasmas within vectors kept elusive. In this study, spatiotemporal dynamics of onion yellows (OY) phytoplasma in its vector Macrosteles striifrons was investigated by immunohistochemistry-based 3D imaging visualization, whole-mount fluorescence staining, and real-time quantitative PCR. The results indicated that OY phytoplasmas entered the anterior midgut epithelium by 7 days after acquisition start (daas), then moved to the visceral muscles surrounding the midgut, to the hemocoel at 14-21 daas, and finally invaded into the type III cells of salivary glands at 21-28 daas. The anterior midgut of the alimentary canal and type III cells of the salivary glands were identified as the major sites of OY phytoplasma infection. Fluorescence staining further revealed that OY phytoplasmas spread along the actin-based muscle fibers of the visceral muscles, and accumulated on the surface of salivary gland cells, that is important for phytoplasma invasion into type III cells of salivary glands, and thus successful insect transmission. This is the first comprehensive study to demonstrate spatiotemporal dynamics of phytoplasmas in insect vectors. The findings from this study will help understand the underlying mechanism of insect-borne plant pathogen transmission.