RNA interference for the control of whiteflies (Bemisia tabaci) by oral route

Abstract

RNA interference (RNAi)-mediated gene silencing was explored for the control of sap-sucking pest Bemisia tabaci, commonly known as whitefly. dsRNAs and siRNAs were synthesized from five different genes - actin ortholog, ADP/ATP translocase, alpha-tubulin, ribosomal protein L9 (RPL9) and V-ATPase A subunit. A simplified insect bioassay method was developed for the delivery of ds/siRNA through the oral route, and efficacy was evaluated. ds/siRNA caused 29-97% mortality after 6 days of feeding. Each insect ingested nearly 150 nl of insect diet per day, which contained a maximum of 6 ng of RNA. Knocking down the expression of RPL9 and V-ATPase A caused higher mortality with LC50 11.21 and 3.08 microg/ml, respectively, as compared to other genes. Semi-quantitative PCR of the treated insects showed significant decrease in the level of RPL9 and V-ATPase A transcripts. siRNAs were found stable in the insect diet for at least 7 days at the room temperature. Phloem-specific expression of dsRNAs of RPL9 and V-ATPase A in transgenic plants for the protection against whiteflies might be an interesting application of this technology.

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].…”

Agricultural production: assessment of the potential use of Cas9-mediated gene drive systems for agricultural pest control

“…The plant-feeding habits of many of these insects make it likely that future population control strategies are likely to include the use of plant-based systemic RNA interference (RNAi) to some extent (Upadhyay et al 2011). Basic functional genomics tools still need to be developed for many of these species to aid in identifying genes that can act as targets for plant-based gene silencing strategies.…”

DNA Sequencing and Crop Protection

“…In fact the current expression of Bt insecticidal proteins in plant offers a better degree of protection in field condition against Lepidoptera and Coleoptera, while none of Cry toxins of B. thuringiensis is effective on sup-sucking pests (Virla et al, 2010). The good new results obtained with the whitefly Bemisia tabaci (Gennadius) (Upadhyay et al, 2011), the aphid M. persicae (Pitino et al, 2011) and the brown planthopper Nilaparvata lugens Stål (Zha et al, 2011) are promising. Anyhow, recent reports of resistance to Bt toxins expressed in the plants (Tabashnik et al, 2008) will provide more interest for alternative strategies also for Lepidoptera and Coleoptera.…”