Transcriptome Analyses of Diaphorina citri Midgut Responses to Candidatus Liberibacter Asiaticus Infection

Abstract

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important transmission vector of the citrus greening disease Candidatus Liberibacter asiaticus (CLas). The D. citri midgut exhibits an important tissue barrier against CLas infection. However, the molecular mechanism of the midgut response to CLas infection has not been comprehensively elucidated. In this study, we identified 778 differentially expressed genes (DEGs) in the midgut upon CLas infection, by comparative transcriptome analyses, including 499 upregulated DEGs and 279 downregulated DEGs. Functional annotation analysis showed that these DEGs were associated with ubiquitination, the immune response, the ribosome, endocytosis, the cytoskeleton and insecticide resistance. KEGG enrichment analysis revealed that most of the DEGs were primarily involved in endocytosis and the ribosome. A total of fourteen DEG functions were further validated by reverse transcription quantitative PCR (RT-qPCR). This study will contribute to our understanding of the molecular interaction between CLas and D. citri.Insects 2020, 11, 171 2 of 16 poisoning of farmers, environmental pollution and insect resistance [8,9]. Some researchers have focused on the olfactory system of D. citri, revealing a suite of odorants that can be used to develop affordable and safe odor-based surveillance for D. citri control [10]. Yu et al. revealed that the silencing of D. citri muscle protein 20 (DcMP20) resulted in significant mortality and reduced the body weight of D. citri [11]. By RNA interference (RNAi) technology, the knockdown of D. citri tropomyosin1-X1 (DcTm1-X1) significantly increased the mortality rate of nymphs [12]. Although some success regarding the control of D. citri has been achieved, the threats caused by HLB are going to continue. It is essential to investigate the molecular mechanisms of HLB transmission in D. citri.Both D. citri adults and nymphs can transmit CLas. Recent studies suggested that the pathogen multiplies in D. citri after acquisition and becomes distributed among various internal tissues, including the alimentary canal, salivary glands, hemolymph, filter chamber, midgut, fat body, muscle tissues and ovaries [13][14][15]. Among these tissues, the midgut is the first barrier that the bacterium must breach before entry into the hemolymph, indicating that the midgut plays an important role in CLas infection [16]. Pathogens can manipulate the host's essential biological processes during the host-pathogen interaction, e.g., by changing protein translation, vesicular transport and protein metabolism [17,18]. In the midgut, many genes and proteins are involved in the defense against pathogens. Wang et al. identified 869 differentially expressed genes (DEGs) in the Bombyx mori larval midgut via comparative transcriptome analysis. The results showed that many of the DEGs were associated with protein metabolism, the cytoskeleton and apoptosis [19]. Bao et al. performed a transcriptome-wide analysis on the Nilaparvata lugens intestine, an...

Genome-wide analysis of long non-coding RNAs in adult tissues of the melon fly, Zeugodacus cucurbitae (Coquillett)

“…Then PCR was performed with Universal PCR primers, Phusion High-Fidelity DNA polymerase, and Index (X) Primer. In the end, an AMPure XP system (Beckman Coulter) was implemented in purification of PCR products, and evaluation of library quality was performed on an Agilent 2100 Bioanalyzer (Agilent, Palo Alto, CA, USA) [45]. After the libraries were prepared, sequencing was performed on an Illumina Hiseq platform by Biomarker Technologies (Beijing, China).…”

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

“…The draft genome sequence of D. citri is available in the National Center for Biotechnology Information (NCBI). Accordingly, recent studies have continuously provided more information on the transcriptomic and proteomic changes regarding the species' hemolymph and midgut (Vyas et al, 2015;Gill et al, 2017;Kruse et al, 2017Kruse et al, , 2018Yu et al, 2020), revealing the effects of CLas infection on D. citri's nutrition metabolism, nymphal development, and immunity. Most aforementioned previous studies have focused on specific tissues of D. citri due to their implication in the insect's immune system.…”

Annotation and analysis ofyellow genesinDiaphorina citri, vector for the Huanglongbing disease

“…RNA-Seq data were sourced from insects raised on C. sinensis and C. medica (NCBI BioProject PRJNA609978). (b) Comparative expression levels in the gut [34] and midgut [36] of D. citri adults.…”

“…Comparative expression levels of the D. citri yellow 6 and yellow 7 (d) proteins in D. citri gut [34] and midgut [36] of infected and uninfected adult insects. Values are represented in transcripts per million (TPM).…”