Genetic variation and potential coinfection of Wolbachia among widespread Asian citrus psyllid (Diaphorina citri Kuwayama) populations

Abstract

Wolbachia can profoundly influence the survival, reproduction, and defenses of insect hosts. These interactions could potentially be harnessed for managing pests or insecttransmitted diseases. Diaphorina citri Kuwayama is a phloem-feeding pest capable of transmitting the putative causal agent of citrus greening, Candidatus Liberibacter asiaticus (CLas). Like many insects, D. citri is also infected with Wolbachia (wDi). Recent studies indicate that the relative abundance of wDi could be associated with the abundance of CLas, and that wDi may contribute to regulating expression of phage lytic cycle genes in CLas, suggesting the need for better understanding of wDi biology in general. This study investigated the genetic diversity of wDi among D. citri in populations spanning eleven countries and two U.S. territories. Six Wolbachia genes, wsp, coxA, fbpA, ftsZ, gatB, and hcpA, were sequenced and compared across samples. Two prevalent wDi strains were identified across the samples, and screening of clone libraries revealed possible coinfection of wDi strains in specific populations. D. citri mitochondrial cytochrome oxidase subunit I gene (mtCOI) were more divergent between D. citri populations that were infected with different wDi strains or had different infection statuses (single infection vs. coinfection). While we could not eliminate the possibility that maternal transmission may contribute to such patterns, it is also possible that wDi may induce cytoplasmic incompatibility in their host. These findings should contribute to the understanding of wDi population ecology, which may facilitate manipulation of this endosymbiont for management of citrus greening disease worldwide.

Evolution ofWolbachiaMutualism and Reproductive Parasitism: Insight from Two Novel Strains that Co-infect Cat Fleas

“…Horizontal transmission is also evident from hosts infected with multiple Wolbachia strains (41)(42)(43), though little is known about the dynamics and stability of Wolbachia co-infections (44). For instance, in host populations showing variability in single-versus double-infections, does co-infection reflect a transitory phase (i.e.…”

Development on Citrus medica infected with ‘Candidatus Liberibacter asiaticus’ has sex-specific and -nonspecific impacts on adult Diaphorina citri and its endosymbionts

“…The major endosymbionts of D. citri, 'Candidatus Carsonella ruddii', 'Candidatus Profftella armatura', and Wolbachia [36][37][38][39], are differentially abundant in the presence of CLas, depending on D. citri sex [19,34]. Carsonella and Profftella reside in the bacteriome and are transovarially transmitted to progeny [40].…”

“…The major endosymbionts of D . citri , ‘ Candidatus Carsonella ruddii’, ‘ Candidatus Profftella armatura’, and Wolbachia [ 36 – 39 ], are differentially abundant in the presence of CLas, depending on D . citri sex [ 19 , 34 ].…”

Improving Suppression of Hemipteran Vectors and Bacterial Pathogens of Citrus and Solanaceous Plants: Advances in Antisense Oligonucleotides (FANA)

“…Insects infected with CLas were collected from a subset of the uninfected D. citri culture reared on CLas-positive "Pineapple" sweet orange [Citrus sinensis (L.)] plants. Both psyllid colonies were maintained at 26 ± 1 • C, 60-80% relative humidity and a photoperiod of 16:8 (L:D) h. To confirm the absence/presence of the bacterium in the colonies, random subsamples of both plants and insects were tested monthly using a quantitative real-time polymerase chain reaction procedure (Li et al, 2006;Chu et al, 2016Chu et al, , 2019. We produced four or more biological replicates for independent sample collection.…”