Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Portici, Italy.
Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, Bari, Italy.
PLoS One. 2022 Aug 29;17(8):e0272028. doi: 10.1371/journal.pone.0272028. eCollection 2022.
Philaenus spumarius is a cosmopolitan species that has become a major threat to European agriculture being recognized as the main vector of the introduced plant pathogen Xylella fastidiosa, the agent of the "olive quick decline syndrome", a disease which is devastating olive orchards in southern Italy. Wolbachia are bacterial symbionts of many insects, frequently as reproductive parasites, sometime by establishing mutualistic relationships, able to spread within host populations. Philaenus spumarius harbors Wolbachia, but the role played by this symbiont is unknown and data on the infection prevalence within host populations are limited. Here, the Wolbachia infection rate was analyzed in relation to the geographic distribution and the genetic diversity of the Italian populations of P. spumarius. Analysis of the COI gene sequences revealed a geographically structured distribution of the three main mitochondrial lineages of P. spumarius. Wolbachia was detected in half of the populations sampled in northern Italy where most individuals belonged to the western-Mediterranean lineage. All populations sampled in southern and central Italy, where the individuals of the eastern-Mediterranean lineage were largely prevalent, were uninfected. Individuals of the north-eastern lineage were found only in populations from the Alps in the northernmost part of Italy, at high altitudes. In this area, Wolbachia infection reached the highest prevalence, with no difference between north-eastern and western-Mediterranean lineage. Analysis of molecular diversity of COI sequences suggested no significant effect of Wolbachia on population genetics of P. spumarius. Using the MLST approach, six new Wolbachia sequence types were identified. Using FISH, Wolbachia were observed within the host's reproductive tissues and salivary glands. Results obtained led us to discuss the role of Wolbachia in P. spumarius, the factors influencing the geographic distribution of the infection, and the exploitation of Wolbachia for the control of the vector insect to reduce the spread of X. fastidiosa.
斑翅果蝇是一种世界性物种，已成为欧洲农业的主要威胁，被认为是引入植物病原体韧皮部坏死病菌（Xylella fastidiosa）的主要载体，该病原体是导致意大利南部橄榄园迅速衰退的疾病的罪魁祸首。沃尔巴克氏体是许多昆虫的细菌共生体，通常作为生殖寄生虫存在，有时通过建立互利关系来传播。斑翅果蝇体内存在沃尔巴克氏体，但这种共生体的作用尚不清楚，而且有关宿主种群内感染率的数据有限。在这里，分析了意大利斑翅果蝇种群的地理分布和遗传多样性与沃尔巴克氏体感染率的关系。COI 基因序列分析揭示了斑翅果蝇三个主要线粒体谱系的地理结构分布。在意大利北部采集的一半种群中检测到了沃尔巴克氏体，其中大多数个体属于西部-地中海谱系。在意大利南部和中部采集的所有种群均未感染，而东部-地中海谱系的个体则大量存在。在意大利最北部阿尔卑斯山脉的高海拔地区发现了东北谱系的个体。在该地区，沃尔巴克氏体感染率最高，东北谱系与西部-地中海谱系之间没有差异。COI 序列分子多样性分析表明，沃尔巴克氏体对斑翅果蝇的种群遗传没有显著影响。使用 MLST 方法，鉴定了六个新的沃尔巴克氏体序列类型。使用 FISH 技术，在宿主的生殖组织和唾液腺中观察到了沃尔巴克氏体。研究结果促使我们讨论了沃尔巴克氏体在斑翅果蝇中的作用、影响感染地理分布的因素，以及利用沃尔巴克氏体控制媒介昆虫以减少韧皮部坏死病菌传播的可能性。
