Asian citrus psyllid RNAi pathway - RNAi evidence

Authors: TANNING, CLAUVIS - Ghent University; ANDRADE, EDUARDO - Embprapa; Hunter, Wayne; CHRISTIAENS, OLIVIER - Ghent University; SMAGGHE, GUY - Ghent University

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2016
Publication Date: 11/30/2016
Citation: Tanning, C., Andrade, E., Hunter, W.B., Christiaens, O., Smagghe, G. 2016. Asian citrus psyllid RNAi pathway - RNAi evidence. Scientific Reports. 6(38082). http://dx.doi.org/10.1038/srep38082.
DOI: https://doi.org/10.1038/srep38082

Interpretive Summary: Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as Ribonucleic acid interference (RNAi), could provide a new sustainable and environmentally friendly strategy for insect management. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian citrus psyllid genome and if the RNAi machinery could be exploited to develop a management strategy for this pest. Bioassays from treated citrus showed that the Asian citrus psyllid was very sensitive to ingested double-stranded Ribonucleic acid (RNA), demonstrating a strong RNAi response. A small dose of double stranded Ribonucleic acid (dsRNA)administered through a citrus flush was enough to trigger the RNAi mechanism, causing significant suppression and increased psyllid mortality. This study provides evidence of a functional RNAi machinery, which could be further exploited to develop RNAi based management strategies for the control of the Asian citrus psyllid to reduce the spread of the pathogen causing citrus greening disease.

Technical Abstract: In silico analyses of the draft genome of Diaphorina citri, the Asian citrus psyllid, for genes within the Ribonucleic acid interference(RNAi), pathway was successful. The psyllid is the vector of the plant-infecting bacterium, Candidatus Liberibacter asiaticus (CLas), which is linked to citrus greening disease. As the most serious problem in citrus worldwide, efforts are aimed at reducing psyllid populations in citrus. Highly specific, biotechnologies, like RNAi could provide a new sustainable and environmentally friendly strategy to manage insects. In this study, genome and functional analysis verified the RNAi core genes and the functionality of the RNAi mechanism in psyllid. Analyses showed the Asian citrus psyllid was very sensitive to ingested double stranded Ribonucleic acid (dsRNA), demonstrating a strong RNAi response. A small dose of dsRNA administered through a citrus flush was enough to trigger the RNAi mechanism, causing significant increase in psyllid mortality. This study provides evidence of a functional RNAi machinery, which could be further exploited to develop RNAi based management strategies for the control of the Asian citrus psyllid.