Analysis of Transcriptome Differences between Resistant and Susceptible Strains of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae)

Abstract

BackgroundThe citrus red mite is a worldwide citrus pest and a common sensitizing allergen of asthma and rhinitis. It has developed strong resistance to many registered acaricides, However, the molecular mechanisms of resistance remain unknown. we therefore used next generation sequencing technology to investigate the global transcriptomes between resistant strains and susceptible strains.ResultsWe obtained 34,159, 30,466 and 32,217 unigenes by assembling the SS reads, RS reads and SS&RS reads respectively. There are total 17,581 annotated unigenes from SS&RS reads by BLAST searching databases of nr, the Clusters of Orthologous Groups (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) with an E-value ≤ 1e-5, in which 7,075 unigenes were annotated in the COG database, 12, 712 unigenes were found in the KEGG database and 3,812 unigenes were assigned to Gene ontology (GO). Moreover, 2,701 unigenes were judged to be the differentially expressed genes (DEGs) based on the uniquely mapped reads. There are 219 pathways in all annotated unigenes and 198 pathways in DEGs that mapped to the KEGG database. We identified 211 metabolism genes and target genes related to general insecticide resistance such as P450 and Cytochrome b, and further compared their differences between RS and SS. Meanwhile, we identified 105 and 194 genes related to growth and reproduction, respectively, based on the mode of action of Hexythiazox. After further analyses, we found variation in sequences but not in gene expression related to mite growth and reproduction between different strains.ConclusionTo our knowledge, this is the first comparative transcriptome study to discover candidate genes involved in phytophagous mite resistance. This study identified differential unigenes related to general pesticide resistance and organism growth and reproduction in P. citri. The assembled, annotated transcriptomes provide a valuable genomic resource for further understanding the molecular basis of resistance mechanisms.

Molecular cloning of heat shock protein gene HSP90 and effects of abamectin and double-stranded RNA on its expression inPanonychus citri(Trombidiformes: Tetranychidae)

“…Development of resistance in arthropods is mainly caused by decreased target sensitivity and increased activity of detoxifying enzymes Liu et al 2011). Although acaricide resistance in P. citri is rampant, there is less research on the elucidation of resistance mechanisms in this mite than on other arthropods, and, thus, the molecular mechanism for resistance of P. citri to most acaricides remains unclear .…”

“…The citrus red mite, Panonychus citri McGregor (Trombidiformes: Tetranychidae), is a citrus pest widely distributed throughout the world, including in the citrus growing areas of China (Liu et al 2011;Xia et al 2014). P. citri punctures and feeds on the contents of cells, mainly of leaves, tender shoots, flower buds and fruit of citrus plants.…”

De novo RNA-Seq and functional annotation of Sarcoptes scabiei canis

“…In recent years, the initiation of RNA-Seq for the readily available agricultural mites and culturable mites has provided references for transcriptome analysis of Sarcoptes mites, including Tetranychidae (Liu et al 2011;Miodrag et al 2011;Xu et al 2014), Phytoseiidae (Cabrera et al 2011;Hoy et al 2013), Varroidae (Conte et al 2011), Dermanyssidae (Schicht et al 2013), Acaridae (Stuglik et al 2014), and Pyroglyphidae (Chan et al 2015). Our breakthrough in RNA extraction and cDNA library construction of Psoroptes cuniculi Zhao et al 2016) laid further foundation for the RNA-Seq of Sarcoptes mites, where the efficiency of RNA extraction was enhanced greatly as the number of mites needed for RNA extraction decreased from 20, 000 to 30,000 (250-700 mg; Lee et al 1999;Kenyon et al 2003) to 10.…”

Differential Analysis of the Cytochrome p450 Acaricide-Resistance Genes inPanonychus citri(Trombidiformes: Tetranychidae) Strains

“…The global transcriptome of resistant (RR) and susceptible (SS) strains of P. citri has been sequenced (Liu et al 2011a). A total of 34,159, 30,466 and 32,217 transcripts were identified by assembling SS reads, RR reads and SS plus RR reads after filtration of the low quality reads, respectively, in which 121 unigenes were related to cytochrome P450 monoxygenases.…”

“…A total of 34,159, 30,466 and 32,217 transcripts were identified by assembling SS reads, RR reads and SS plus RR reads after filtration of the low quality reads, respectively, in which 121 unigenes were related to cytochrome P450 monoxygenases. Only 46 P450s were functionally annotated according to their degree of sequence matching, owing to the low sequence similarity of other P450s (Liu et al 2011a). To clarify the relationship between resistance of P. citri and P450 genes, we compared the sequences of P450 genes between RR and SS strains.…”