LAUSR

BACKGROUND The endosymbiont Wolbachia is known for manipulating host reproduction. Wolbachia can also affect host fitness by mediating interactions between plant and herbivores. However, it remains unclear whether saliva proteins are involved in this process. RESULTS We found that Wolbachia infection decreased the number of deposited eggs but increased the egg hatching rate in the spider mite Tetranychus urticae Koch (Acari: Tetranychidae), a cosmopolitan pest that infects more than 1000 species of plants. Transcriptomic and proteomic analyses revealed that Wolbachia-infected mites upregulated the gene expression levels of many T. urticae salivary proteins including a cluster of Tetranychidae-specific, functionally uncharacterized SHOT1s (secreted host-responsive proteins of Tetranychidae). The SHOT1 genes were expressed more in the feeding stages (nymphs and adults) of miters than in eggs and highly enriched in the proterosomas. RNA interference experiments showed knockdown of SHOT1s significantly decreased Wolbachia density, increased the number of deposited eggs and decreased the egg hatching rate. CONCLUSION Together, these results indicate that SHOT1s are positively correlated with Wolbachia density and account for Wolbachia-mediated phenotypes. Our results provide new evidence that herbivore salivary proteins are related to Wolbachia-mediated manipulations of host performance on plants. This article is protected by copyright. All rights reserved.