Spatiotemporal dynamics and quantitative analysis of phytoplasmas in insect vectors
Spatiotemporal dynamics and quantitative analysis of phytoplasmas in insect vectors
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DOI：
10.1038/s41598-020-61042-x
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发表时间：
2020-03-09
影响因子：
4.6
通讯作者：
Yamaji, Yasuyuki
中科院分区：
文献类型：
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作者：
Koinuma, Hiroaki;Maejima, Kensaku;Yamaji, Yasuyuki
植原体通过昆虫媒介以持续的繁殖方式传播，然而，植原体在媒介中的详细运动和繁殖模式仍然难以捉摸。在这项研究中，通过基于免疫组织化学的3D成像、整体荧光染色和实时定量PCR研究了洋葱黄（OY）植原体在其载体Macrosteles striifrons中的时空动态。结果表明，OY植原体在感染开始后7 d进入中肠前壁上皮细胞，14-21 d进入中肠周围内脏肌和血腔，21-28 d进入唾液腺III型细胞。消化道中肠前部和唾液腺III型细胞是OY植原体感染的主要部位。荧光染色进一步显示，OY植原体沿着内脏肌肌动蛋白基肌纤维传播，并聚集在唾液腺细胞表面。这种积累对于植原体侵入唾液腺，从而对于成功的昆虫传播是重要的。本研究表明植原体在昆虫媒介中的时空动态。本研究的结果将有助于了解昆虫传播植物病原体的潜在机制。
Phytoplasmas are transmitted by insect vectors in a persistent propagative manner; however, detailed movements and multiplication patterns of phytoplasmas within vectors remain elusive. In this study, spatiotemporal dynamics of onion yellows (OY) phytoplasma in its vector Macrosteles striifrons were investigated by immunohistochemistry-based 3D imaging, whole-mount fluorescence staining, and real-time quantitative PCR. The results indicated that OY phytoplasmas entered the anterior midgut epithelium by seven days after acquisition start (daas), then moved to visceral muscles surrounding the midgut and to the hemocoel at 14-21 daas; finally, OY phytoplasmas entered into type III cells of salivary glands at 21-28 daas. The anterior midgut of the alimentary canal and type III cells of 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 visceral muscles and accumulated on the surfaces of salivary gland cells. This accumulation would be important for phytoplasma invasion into salivary glands, and thus for successful insect transmission. This study demonstrates the spatiotemporal dynamics of phytoplasmas in insect vectors. The findings from this study will aid in understanding of the underlying mechanism of insect-borne plant pathogen transmission.