Data from: Correlation between the green-island phenotype and Wolbachia infections during the evolutionary diversification of Gracillariidae leaf-mining moths

Internally feeding herbivorous insects such as leaf miners have developed the ability to manipulate the physiology of their host plants in a way to best meet their metabolic needs and compensate for variation in food nutritional composition. For instance, some leaf miners can induce green-islands on yellow leaves in autumn, which are characterized by photosynthetically active green patches in otherwise senescing leaves. It has been shown that endosymbionts, and most likely bacteria of the genus Wolbachia, play an important role in green-island induction in the apple leaf-mining moth Phyllonorycter blancardella. However, it is currently not known how widespread is this moth-Wolbachia-plant interaction. Here, we studied the co-occurrence between Wolbachia and the green-island phenotype in 133 moth specimens belonging to 74 species of Lepidoptera including 60 Gracillariidae leaf miners. Using a combination of molecular phylogenies and ecological data (occurrence of green-islands), we show that the acquisitions of the green-island phenotype and Wolbachia infections have been associated through the evolutionary diversification of Gracillariidae. We also found intraspecific variability in both green-island formation and Wolbachia infection, with some species being able to form green-islands without being infected by Wolbachia. In addition, Wolbachia variants belonging to both A and B supergroups were found to be associated with green-island phenotype suggesting several independent origins of green-island induction. This study opens new prospects and raises new questions about the ecology and evolution of the tripartite association between Wolbachia, leaf miners, and their host plants.

潜食性植食性昆虫（如潜叶昆虫）已演化出调控宿主植物生理机能的能力，以最优匹配自身代谢需求并弥补食物营养组成的波动。例如，部分潜叶昆虫可在秋季泛黄的叶片上诱导形成绿岛（green-islands），这类结构的典型特征是在整体趋于衰老的叶片中出现具有光合活性的绿色斑块。已有研究表明，内共生体——极有可能为沃尔巴克氏体属（Wolbachia）细菌——在苹果潜叶蛾（Phyllonorycter blancardella）的绿岛诱导过程中发挥关键作用。然而，目前学界尚不清楚这种蛾类-沃尔巴克氏体-植物的互作关系的分布广度。本研究针对133份隶属于74种鳞翅目的蛾类标本展开分析，其中包含60种细蛾科（Gracillariidae）潜叶蛾，通过结合分子系统发育数据与生态学观测数据（绿岛发生情况），探究了沃尔巴克氏体与绿岛表型之间的共存现象。研究结果显示，在细蛾科的演化辐射过程中，绿岛表型的获得与沃尔巴克氏体感染存在显著关联。本研究还观测到，绿岛形成能力与沃尔巴克氏体感染均存在种内变异，部分物种可在未感染沃尔巴克氏体的情况下形成绿岛。此外，隶属于A、B两个超群的沃尔巴克氏体变异株均与绿岛表型相关，提示绿岛诱导能力存在多次独立起源。本研究为沃尔巴克氏体、潜叶昆虫与宿主植物之间的三方互作关系的生态学与演化研究开辟了全新视角，同时也提出了诸多亟待解答的新问题。