RNAi-mediated mortality of the whitefly through transgenic expression of double-stranded RNA homologous to acetylcholinesterase and ecdysone receptor in tobacco plants

Abstract

The whitefly Bemisia tabaci (Genn.) is a pest and vector of plant viruses to crop and ornamental plants worldwide. Using RNA interference (RNAi) to down regulate whitefly genes by expressing their homologous double stranded RNAs in plants has great potential for management of whiteflies to reduce plant virus disease spread. Using a Tobacco rattle virus-derived plasmid for in planta transient expression of double stranded RNA (dsRNA) homologous to the acetylcholinesterase (AChE) and ecdysone receptor (EcR) genes of B. tabaci, resulted in significant adult whitefly mortality. Nicotiana tabacum L. plants expressing dsRNA homologous to B. tabaci AChE and EcR were constructed by fusing sequences derived from both genes. Mortality of adult whiteflies exposed to dsRNA by feeding on N. tabacum plants, compared to non-dsRNA expressing plants, recorded at 24-hr intervals post-ingestion for three days, was >90% and 10%, respectively. Analysis of gene expression by real time quantitative PCR indicated that whitefly mortality was attributable to the down-regulation of both target genes by RNAi. Results indicated that knock down of whitefly genes involved in neuronal transmission and transcriptional activation of developmental genes, has potential as a bio-pesticide to reduce whitefly population size and thereby decrease virus spread.

Recent Biotechnological Advances in the Improvement of Cassava

“…In cassava improvement, hpRNA and antisense silencing procedures have been employed mostly in virus control [52][53][54][55][56]. An indirect approach where the hpRNA is used to knockdown the expression of V-ATPase A, an enzyme that provides force for many transport processes, has been used to control whitefly vectors of CMGs and CBSVs [57,58].…”

Implementing the sterile insect technique with RNA interference – a review

“…In this context, the development of new methods for insect control is of key importance and there has been intense interest in the utility of gene silencing methods induced by RNA interference (RNAi). RNAi can induce mortality (Yang & Han, ; Cao et al., ; Abd El Halim et al., ; Christiaens et al., ; Hu et al., ; Malik et al., ), create beneficial phenotypes for insect control (Salvemini et al., ; Shukla & Palli, ; Peng et al., ; Yu et al., ), and prevent pesticide resistance in insect pests (Figueira‐Mansur et al., ; Guo et al., ; Wei et al., ; Bona et al., ; Sandoval‐Mojica & Scharf, ). Therefore, the potential for RNAi as a basis for future pest management strategies holds great promise (Huvenne & Smagghe, ; Gu & Knipple, ; Scott et al., ; Baum & Roberts, ; Kim et al., ).…”

“…Genes that can induce sterility when knocked down can be targeted in adult insects for use with SIT. eRNAi has been demonstrated to successfully achieve gene silencing in adults following ingestion of: (1) dsRNA‐expressing transgenic plants (Coleman et al., ; Tzin et al., ; Malik et al., ), (2) dsRNA‐expressing transgenic bacteria (Li et al., ; Taracena et al., ; Whitten et al., ), (3) dsRNA dissolved in solution (Coy et al., ; Ratzka et al., ; Shim et al., ), and (4) naked dsRNA overlaid on diet (Yi et al., ; Zheng et al., ). In addition, topical application to adults of dsRNA (Pridgeon et al., ; Killiny et al., ; Amiri et al., ) and infection with transgenic fungi (Chen et al., ) are reported.…”

Quantification of dsRNA using stable isotope labeling dilution liquid chromatography/mass spectrometry

“…E. coli ‐mediated delivery of dsRNA has been reported in C. elegans, planarians, Entamoeba histolytica and Spodoptera exigua . Furthermore, a number of RNAi‐based insect management strategies have also employed the ingestion of bacteria‐expressing dsRNA, application of chemically synthesised dsRNA and transgenic plants expressing dsRNA . To ensure RNAi gene silencing using the above approaches, it is important to both produce and deliver the required amounts of dsRNA.…”

“…6 Furthermore, a number of RNAi-based insect management strategies have also employed the ingestion of bacteria-expressing dsRNA, 7 application of chemically synthesised dsRNA 8 and transgenic plants expressing dsRNA. 6,9 To ensure RNAi gene silencing using the above approaches, it is important to both produce and deliver the required amounts of dsRNA. Therefore, the necessary analytical tools to quantify the dsRNA are important to both optimise production strategies and ensure delivery of the required amounts of dsRNA.…”