The bacterium Rickettsia is found widely in phytophagous insects and often exerts profound effects on the phenotype and fitness of its hosts. Here, we decrypt a new, independent, phylogenetically ancient Torix Rickettsia endosymbiont found constantly in a laboratory line of an economically important insect Asia II 7, a putative species of the Bemisia tabaci whitefly complex (Hemiptera: Aleyrodidae), and occasionally in field whitefly populations. This new Rickettsia distributes throughout the body of its whitefly host. Genetically, compared to Rickettsia_bellii_MEAM1 found earlier in whiteflies, the new Rickettsia species has more gene families and pathways, which may be important factors in shaping specific symbiotic relationships. We propose the name 'Candidatus Rickettsia_Torix_Bemisia_tabaci (RiTBt)' for this new endosymbiont associated with whiteflies. Comparative genomic analyses indicate that RiTBi may be a relatively recent intruder in whiteflies given its low abundance in the field and relatively larger genome compared to Rickettsia_bellii_MEAM1.

中文翻译：

---

最近记录的Torix组立克次体是最近入侵者和烟粉虱烟粉虱中的共生共生体。

立克次体细菌广泛存在于植物吞噬性昆虫中，并经常对其宿主的表型和适应性产生深远影响。在这里，我们解密一种新的，独立的，系统发育的古老的鸟立克氏立克次体内共生体，该新种在经济上很重要的昆虫Asia II 7的实验室中不断发现，该昆虫是Bemisia tabaci粉虱复合体（半翅目：Aleyrodidae）的偶发物种，偶尔在田间粉虱种群中。这种新的立克次体分布在其粉虱寄主的整个身体中。从遗传上讲，与粉虱早期发现的立克次体_bellii_MEAM1相比，新的立克次体物种具有更多的基因家族和途径，这可能是形成特定共生关系的重要因素。我们建议使用名称“ Candidatus Rickettsia_Torix_Bemisia_tabaci（RiTBt）” 用于与粉虱相关的新共生共生体。比较基因组分析表明，与Rickettsia_bellii_MEAM1相比，RiTBi在田间的丰度较低且基因组相对较大，因此可能是粉虱中相对较新的入侵者。