Identifying the Gut Virome of Diaphorina citri from Florida Groves

SIMPLE SUMMARY: Controlling Asian citrus psyllid (Diaphorina citri), the insect vector of Candidatus Liberibacter asiaticus (CLas), is an important part of Huanglongbing management. Specific viruses were recently discovered in a psyllid host where they may act as biological agents for minimizing psyllid populations or CLas transmission. We analyzed the psyllid gut virome from five regions in Florida and identified four D. citri-associated viruses at different compositions. The presence of these specific viruses in the gut indicated potential interactions between these viruses and CLas. Our results provided evidence that D. citri-associated viruses located in the host gut and their potential activities may be useful for pest management. ABSTRACT: Asian citrus psyllid (Diaphorina citri) transmits the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), the putative causative agent of citrus Huanglongbing disease (HLB). Insect-specific viruses can act against insects as their natural enemies, and recently, several D. citri-associated viruses were discovered. The insect gut plays an important role as not only a pool for diverse microbes but also as a physical barrier to prevent the spread of pathogens such as CLas. However, there is little evidence of the presence of D. citri-associated viruses in the gut and of the interaction between them and CLas. Here, we dissected psyllid guts collected from five growing regions in Florida, and the gut virome was analyzed by high throughput sequencing. Four insect viruses, including D. citri-associated C virus (DcACV), D. citri densovirus (DcDV), D. citri reovirus (DcRV), and D. citri flavi-like virus (DcFLV), were identified, and their presence in the gut, including an additional D. citri cimodo-like virus (DcCLV), were confirmed with PCR-based assays. Microscopic analysis showed that DcFLV infection leads to morphological abnormalities in the nuclear structure in the infected psyllid gut cells. The complex and diverse composition of microbiota in the psyllid gut suggests a possible interaction and dynamics between CLas and the D. citri-associated viruses. Our study identified various D. citri-associated viruses that localized in the psyllid gut and provided more information that helps to evaluate the potential vectors for manipulating CLas in the psyllid gut.