Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri

Abstract

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB). The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi) has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA). In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control.

Effect of parental RNA interference of a transformer‐2 homologue on female reproduction and offspring sex determination in Asian citrus psyllid

“…An effective RNAi response in insects depends on an efficient delivery system for dsRNA (Yu et al ., , ). RNAi experiments in D. citri can be conducted using micro‐application of dsRNA (El‐Shesheny et al ., ; Killiny et al ., ; Kishk et al ., ), soaking (Yu et al ., ), virus‐based RNAi (Hajeri et al ., ), in planta systems (Taning et al ., ; Andrade & Hunter, ) and artificial feeding (Galdeano et al ., ). The results of the present study demonstrate that feeding virgin female adults on an artificial diet containing ds Dctra‐2 results in significant RNAi.…”

“…Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the most important insect pest of citrus because it serves as a vector for Candidatus Liberibacter asiaticus (CLas) and Candidatus Liberibacter americanus, which cause citrus huanglongbing disease (HLB) in the U.S.A. and Brazil, respectively (Grafton-Cardwell et al, 2013). All commercially cultivated citrus is susceptible and no cure is currently available for HLB-infected trees (da Graça et al, 2015), resulting in a continued decline of citrus industries. Diaphorina citri possess an XX/XY chromosomal system (XX female and XY male).…”

Evaluation of a cuticle protein gene as a potential RNAi target in aphids

“…In this study, effective gene silencing of CP19 was observed in three aphid species using the plant‐leaf‐mediated dsRNA uptake method. This method was used to characterize the functions of genes encoding cathepsin D, chitin synthase, and the inhibitor of apoptosis in Diaphorina citri . This method was also used in RNAi target selection in the spider mites Tetranychus urticae and Pononychus citri .…”

Effect of silencing a boule homologue on the survival and reproduction of Asian citrus psyllid Diaphorina citri

“…Suitable target genes and efficient dsRNA delivery in insects are the two prerequisites of RNAi‐based insect management (Terenius et al ., ; Scott et al ., ; Yu et al ., ; Yu et al ., ). DsRNA delivery in D. citri has been conducted using artificial feeding (Galdeano et al ., ; Yu & Killiny, , b), soaking (Yu et al ., ), micro‐application of dsRNA (Killiny & Kishk, ; Kishk et al ., ), virus‐based RNAi (Hajeri et al ., ) and in planta systems (Hunter et al ., ; Taning et al ., ; Andrade & Hunter, ). The results of the present study demonstrate that virgin female adults feeding on an artificial diet with ds DcBol cause significant RNAi.…”

“…Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae), as a vector for Candidatus Liberibacter asiaticus (CLas), which causes citrus huanglongbing disease (HLB), is the most important insect pest of citrus in the U.S.A. (Grafton-Cardwell et al, 2013). All commercially cultivated citrus is vulnerable to HLB and no cure is currently available for the disease-ridden trees (da Graça et al, 2015). The present study aims to identify the function of DcBol homologue on male reproduction and evaluate whether DcBol could serve as a potential target for RNAi-based control of D. citri.…”