Transcriptomic and Metabolomic Analyses of Diaphorina citri Kuwayama Infected and Non-infected With Candidatus Liberibacter Asiaticus

Abstract

The Asian citrus psyllid Diaphorina citri is the transmission vector of Huanglongbing (HLB), a devastating disease of citrus plants. The bacterium “Candidatus Liberibacter asiaticus” (CLas) associated with HLB is transmitted between host plants by D. citri in a circulative manner. Understanding the interaction between CLas and its insect vector is key for protecting citrus cultivation from HLB damage. Here, we used RNA sequencing and liquid chromatography-mass spectrometry (LC-MS) to analyze the transcriptome and metabolome of D. citri interacting with CLas. We identified 662 upregulated and 532 downregulated genes in CLas-infected insects. These genes were enriched in pathways involving carbohydrate metabolism, the insects’ immune system, and metabolism of cofactors and vitamins. We also detected 105 differential metabolites between CLas-infected and non-infected insects, including multiple nucleosides and lipid-related molecules. The integrated analysis revealed nine pathways—including those of the glycine, serine, threonine, and purine metabolism—affected by the differentially expressed genes from both groups. The network for these pathways was subsequently constructed. Our results thus provide insights regarding the cross-talk between the transcriptomic and metabolomic changes in D. citri in response to CLas infection, as well as information on the pathways and genes/metabolites related to the CLas–D. citri interaction.

Differential gene expression of Asian citrus psyllids infected with ‘Ca. Liberibacter asiaticus’ reveals hyper-susceptibility to invasion by instar fourth-fifth and teneral adult stages

“…The HSPs have been recognized as important immune-response proteins that combat biological and environmental stresses in well-studied insect systems ( Aguilar et al., 2005 ; Gotz et al., 2012 ). Consistent with the recent report ( Liu et al., 2020 ), in this study, several heat shock protein genes were among the top 50 under-expressed gene list, with some shared among the different life stages/groups ( Additional file 3 ). This differential regulation of HSPs strongly suggests that CLas infection activates and then depresses the ACP immune system to modulate attack by the host at particular times in the infection process over others, relative to key ‘pathogenesis’ requirements required during each different host life stage or group (herein).…”

Detection of Candidatus Liberibacter asiaticus and five viruses in individual Asian citrus psyllid in China

“… 1 Britt et al., 2020 ; 2 Accession number: PP025819; 3 Jagoueix et al, 1994 ; 4 Accession number: PP025816; 5 Liu et al., 2020 ; CLas, Candidatus Liberibacter asiaticus;diaphorina citri reovirus, DcRV; diaphorina citri picorna-like virus, DcPLV; diaphorina citri bunyavirus, DcBV; diaphorina citri densovirus-like virus, DcDV; diaphorina citri bunyavirus 2, DcBV2; F: Forward Primer; R: Reverse Primer; bp: base pair. …”

The molecular interplay of the establishment of an infection – gene expression of Diaphorina citri gut and Candidatus Liberibacter asiaticus

“…We also learned CLas infects salivary glands and the midgut of vectors, tissues that are often recognized as natural barriers to circulative, propagative pathogens as they can prevent translocation of pathogens within the vector host [ 17 , 22 , 26 , 27 ]. Differential gene expression analysis of CLas-infected psyllids also demonstrated CLas alters the gene expression profile of of the gut, salivary glands and whole-body of D. citri [ 19 , 28 – 30 ]. More recently, new information on the higher efficiency of adults than psyllid nymphs as vectors of CLas has been reported, with adults displaying a higher successful rate of infection of healthy citrus plants than nymphs [ 27 ].…”