Impact of transinfection of Wolbachia from the planthopper Laodelphax striatellus on reproductive fitness and transcriptome of the whitefly Bemisia tabaci

The whitefly Bemisia tabaci is critical global pest threatening crops and leading to agricultural losses. Wolbachia is an intracellular symbiotic bacterium in insects, which can regulate the growth and development of the host through various ways. In a prior study, Wolbachia was found to be transferred to whitefly and induce fitness changes. However, little is known about the underlying mechanisms of host-Wolbachia interactions in B. tabaci. In this study, a Wolbachia strain wStri was isolated from the small brown planthopper, Laodelphex striatellus, and transferred to B. tabaci. The distribution of Wolbachia in whiteflies was determined using fluorescence in situ hybridization. Reciprocal crossing experiments demonstrated that wStri did not induce cytoplasmic incompatibility phenotypes in B. tabaci, but prolonged the developmental duration of the offspring. We performed transcriptomic analysis of Wolbachia-infected female and male adults using Illumina-based RNA-Seq. A total of 843 differentially expressed genes (DEGs) were identified in infected females, among them 141 were significantly up-regulated and 702 were down-regulated by Wolbachia infection. In infected males, of 511 gene sets, 279 host genes were significantly up-regulated, and 232 were down-regulated by Wolbachia infection. KEGG analysis of DEGs demonstrated significant differences in gene pathway distribution between up-regulated and down-regulated genes. These genes are involved in various biological processes, including, but not limited to, detoxification, oxidation–reduction, metabolic processes, and immunity. The transcriptomic profiling of this study offers valuable information on the differential expression of genes in whiteflies following Wolbachia infection, and enhances our understanding of this host-symbiotic interaction.