Transcriptomic characterization of Wolbachia endosymbiont from Leuronota fagarae (Hemiptera: Psylloidae)

Aim: Wolbachia species are among the most abundant intracellular endosymbionts of insects worldwide. The extensive distribution of Gram-negative Wolbachia among insects highlights their evolutionary success and close relationship with many insect host species. This study aimed to characterize a novel Wolbachia strain from the Wild Lime Psyllid, Leuronota fagarae (L. fagarae), to understand its evolutionary relationship with Wolbachia from psyllid pests like Diaphorina citri, the vector of Huanglongbing (HLB). Methods: Wild-caught L. fagarae colonies from Florida, USA, were maintained on Zanthoxylum fagara. RNA was extracted from the salivary glands, heads, and whole bodies of male and female adult L. fagarae. Four cDNA libraries were sequenced using short read technology and de novo transcriptome assembly was performed. Multilocus sequence typing (MLST) of nine conserved loci and wsp gene analysis classified the strain's phylogeny, while sequence mapping and functional annotation provided insight into host-microbe interactions. Results: The new Wolbachia strain, designated Wolbachia endosymbiont of Leuronota fagarae (wLfag-FL), was assigned to supergroup B, showing relation to Wolbachia strains of other related psyllids. Transcriptome analysis identified 1,359 Wolbachia transcripts with 465 assigned functions encompassing metabolic and secretion system pathways. Ankyrin domain proteins and a partial bacterioferritin sequence were detected, suggesting nutritional provisioning roles. Conclusion: The characterization of wLfag-FL expands the known Wolbachia host range and informs HLB-related pest biology. Its phylogenetic placement and transcript annotations offer insights into symbiotic interactions, potentially guiding environmentally safe pest control strategies targeting psyllid fitness and pathogen transmission.