State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Microb Pathog. 2018 May;118:378-386. doi: 10.1016/j.micpath.2018.03.046. Epub 2018 Mar 27.
The hispid leaf beetle, Octodonta nipae (Maulik), (Coleoptera: Chrysomelidae), is a devastating pest of palm cultivation worldwide. Endosymbiotic bacteria in the genus Wolbachia are arguably one of the most abundant bacterial group associated with arthropods. Owing to its critical effects on host reproduction, Wolbachia has garnered much attention as a prospective future tool for insect pest management. However, their association, infection dynamics, and functionality remain unknown in this insect pest. Here, we diagnosis for the first time, the infection prevalence, and occurrence of Wolbachia in O. nipae. Experimental evidence by the exploration of wsp gene vindicate that O. nipae is naturally infected with bacterial symbiont of genus Wolbachia, showing a complete maternal inheritance with shared a common Wolbachia strain (wNip). Moreover, MLST (gatB, fbpA, coxA, ftsZ, and hcpA) analysis enabled the detections of new sequence type (ST-484), suggesting a particular genotypic association of O. nipae and Wolbachia. Subsequently, quantitative real-time PCR (qPCR) assay demonstrated variable infection density across different life stages (eggs, larvae, pupae and adult male and female), body parts (head, thorax, abdomen), and tissues (ovaries, testes, and guts). Infection density was higher in egg and female adult stage, as well as abdomen and reproductive tissues as compared to other samples. Interestingly, Wolbachia harbored dominantly in a female than the male adult, while, no significant differences were observed between male and female body parts and tissues. Phylogeny of Wolbachia infection associated with O. nipae rectified from all tested life stages were unique and fall within the same monophyletic supergroup-A of Wolbachia clades. The infection density of symbiont is among the valuable tool to understand their biological influence on hosts, and this latest discovery would facilitate the future investigations to understand the host-symbiont complications and its prospective role as a microbiological agent to reduce pest populations.
糙叶斑叶甲，Octodonta nipae (Maulik)（鞘翅目：叶甲科），是世界范围内棕榈种植的毁灭性害虫。共生细菌沃尔巴克氏体属（Wolbachia）是与节肢动物最相关的最丰富的细菌群体之一。由于其对宿主生殖的关键影响，沃尔巴克氏体属作为昆虫害虫管理的未来潜在工具引起了广泛关注。然而，它们在这种昆虫害虫中的关联、感染动态和功能仍然未知。在这里，我们首次诊断出糙叶斑叶甲中沃尔巴克氏体的感染流行率和发生情况。通过 wsp 基因的探索，实验证据证实糙叶斑叶甲自然感染了细菌共生体沃尔巴克氏体属，表现出完全的母系遗传，并共享一种共同的沃尔巴克氏体菌株（wNip）。此外，MLST（gatB、fbpA、coxA、ftsZ 和 hcpA）分析能够检测到新的序列类型（ST-484），表明糙叶斑叶甲和沃尔巴克氏体之间存在特定的基因型关联。随后，定量实时 PCR（qPCR）检测表明，不同生活阶段（卵、幼虫、蛹和雌雄成虫）、身体部位（头部、胸部、腹部）和组织（卵巢、睾丸和肠道）的感染密度不同。与其他样本相比，卵和雌性成虫阶段以及腹部和生殖组织的感染密度较高。有趣的是，沃尔巴克氏体在雌性中比在雄性成虫中占优势，而在雄性和雌性身体部位和组织之间没有观察到显著差异。从所有测试的生活阶段中，与 O. nipae 相关的沃尔巴克氏体感染的系统发育都具有独特性，并且属于沃尔巴克氏体属的同一单系超群-A。共生体的感染密度是了解其对宿主生物学影响的有价值工具之一，这一最新发现将有助于未来的研究，以了解宿主-共生体的复杂性及其作为减少害虫种群的微生物制剂的潜在作用。
