Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, No. 50, Zhongling Street, Nanjing, 210014, China.
Microb Ecol. 2021 Feb;81(2):523-534. doi: 10.1007/s00248-020-01607-5. Epub 2020 Sep 23.
Maintaining an adaptive seasonality is a basic ecological requisite for cold-blooded organism insects which usually harbor various symbionts. However, how coexisting symbionts coordinate in insects during seasonal progress is still unknown. The whitefly Bemisia tabaci in China harbors the obligate symbiont Portiera that infects each individual, as well as various facultative symbionts. In this study, we investigated whitefly populations in cucumber and cotton fields from May to December 2019, aiming to reveal the fluctuations of symbiont infection frequencies, symbiont coordination in multiple infected individuals, and host plants effects on symbiont infections. The results indicated that the facultative symbionts Hamiltonella (H), Rickettsia (R), and Cardinium (C) exist in field whiteflies, with single (H) and double (HC and HR) infections occurring frequently. Infection frequencies of Hamiltonella (always 100%) and Cardinium (29.50-34.38%) remained steady during seasonal progression. Rickettsia infection frequency in the cucumber whitefly population decreased from 64.47% in summer to 35.29% in winter. Significantly lower Rickettsia infection frequency (15.55%) was identified in cotton whitefly populations and was not subject to seasonal fluctuation. Nevertheless, Rickettsia had a significantly quantitative advantage in the symbiont community of whitefly individuals and populations from both cucumber and cotton field all through the seasons. Moreover, higher Portiera and Hamiltonella densities were found in HC and HR whitefly than in H whitefly, suggesting these symbionts may contribute to producing nutrients for their symbiont partners. These results provide ample cues to further explore the interactions between coexisting symbionts, the coevolutionary relationship between symbionts and host symbiont-induced effects on host plant use.
维持适应季节性是冷血生物昆虫的基本生态要求，通常它们会携带各种共生体。然而，共生体在昆虫季节性进展过程中如何协调仍然未知。在中国，烟粉虱携带专性共生体 Portiera，感染每个个体，以及各种兼性共生体。在这项研究中，我们调查了 2019 年 5 月至 12 月黄瓜和棉花田中的粉虱种群，旨在揭示共生体感染频率的波动、多重感染个体中共生体的协调以及宿主植物对共生体感染的影响。结果表明，兼性共生体 Hamiltonella（H）、Rickettsia（R）和 Cardinium（C）存在于田间粉虱中，单感染（H）和双感染（HC 和 HR）频繁发生。Hamiltonella（始终为 100%）和 Cardinium（29.50-34.38%）的感染频率在季节性进展过程中保持稳定。夏季黄瓜粉虱种群中 Rickettsia 的感染频率从 64.47%下降到冬季的 35.29%。在棉花粉虱种群中，Rickettsia 的感染频率明显较低（15.55%），且不受季节性波动的影响。然而，Rickettsia 在整个季节的黄瓜和棉花田粉虱个体和种群的共生体群落中具有明显的数量优势。此外，在 HC 和 HR 粉虱中发现 Portiera 和 Hamiltonella 的密度高于 H 粉虱，表明这些共生体可能有助于为共生体伙伴提供营养。这些结果为进一步探索共存共生体之间的相互作用、共生体与宿主的共同进化关系以及宿主对共生体诱导的植物利用的影响提供了充分的线索。
