Zhu Dan-Tong, Rao Qiong, Zou Chi, Ban Fei-Xue, Zhao Juan-Juan, Liu Shu-Sheng
Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310029, China.
School of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, 311300, China.
Insect Sci. 2022 Apr;29(2):539-549. doi: 10.1111/1744-7917.12943. Epub 2021 Oct 15.
Nutritional mutualism between insects and symbiotic bacteria is widespread. The various sap-feeding whitefly species within the Bemisia tabaci complex associate with the same obligate symbiont (Portiera) and multiple secondary symbionts. It is often assumed that some of the symbionts residing in the whiteflies play crucial roles in the nutritional physiology of their insect hosts. Although effort has been made to understand the functions of the whitefly symbionts, the metabolic complementarity offered by these symbionts to the hosts is not yet well understood. We examined two secondary symbionts, Arsenophonus and Wolbachia, in two species of the B. tabaci whitefly complex, provisionally named as Asia II 3 and China 1. Genomic sequence analyses revealed that Arsenophonus and Wolbachia retained genes responsible for the biosynthesis of B vitamins. We then conducted transcriptomic surveys of the bacteriomes in these two species of whiteflies together with that in another species named MED of this whitefly complex previously reported. The analyses indicated that several key genes in B vitamin syntheses from the three whitefly species were identical. Our findings suggest that, similar to another secondary symbiont Hamiltonella, Arsenophonus and Wolbachia function in the nutrient provision of host whiteflies. Although phylogenetically distant species of symbionts are associated with their respective hosts, they have evolved and retained similar functions in biosynthesis of some B vitamins. Such metabolic complementarity between whiteflies and symbionts represents an important feature of their coevolution.
昆虫与共生细菌之间的营养共生关系十分普遍。烟粉虱复合体内的各种以吸食汁液为生的粉虱物种都与同一种专性共生菌（Portiera）以及多种次生共生菌相关联。人们通常认为，存在于粉虱体内的一些共生菌在其昆虫宿主的营养生理学中发挥着关键作用。尽管已经努力去了解粉虱共生菌的功能，但这些共生菌为宿主提供的代谢互补性仍未得到充分理解。我们研究了烟粉虱复合体内两个物种（暂命名为亚洲II 3和中国1）中的两种次生共生菌，即嗜菌属和沃尔巴克氏体。基因组序列分析表明，嗜菌属和沃尔巴克氏体保留了负责B族维生素生物合成的基因。然后，我们对这两个粉虱物种以及之前报道的该粉虱复合体另一个名为MED的物种的菌胞进行了转录组调查。分析表明，这三个粉虱物种中参与B族维生素合成的几个关键基因是相同的。我们的研究结果表明，与另一种次生共生菌汉密尔顿菌属类似，嗜菌属和沃尔巴克氏体在为宿主粉虱提供营养方面发挥作用。尽管系统发育上距离较远的共生菌物种与其各自的宿主相关联，但它们在某些B族维生素的生物合成中已经进化并保留了相似的功能。粉虱与共生菌之间的这种代谢互补性代表了它们共同进化的一个重要特征。
