Biotechnological interventions for the sustainable management of a global pest, whitefly (Bemisia tabaci)

Abstract

Whiteflies (Bemisia tabaci) are polyphagous invasive hemipteran insects that cause serious losses of important crops by directly feeding on phloem sap and transmitting pathogenic viruses. These insects have emerged as a major threat to global agriculture and food security. Chemically synthesized insecticides are currently the only option to control whiteflies, but the ability of whiteflies to evolve resistance against insecticides has made the management of these insects very difficult. Natural host-plant resistance against whiteflies identified in some crop plants has not been exploited to a great extent. Genetic engineering approaches, such as transgenics and RNA interference (RNAi), are potentially useful for the control of whiteflies. Transgenic plants harboring insecticidal toxins/lectins developed via nuclear or chloroplast transformation are a promising vehicle for whitefly control. Double-stranded RNAs (dsRNAs) of several insect genes, delivered either through microinjection into the insect body cavity or orally via an artificial diet and transiently or stably expressed in transgenic plants, have controlled whiteflies in model plants and in some crops at the laboratory level, but not at the field level. In this review, we highlight the merits and demerits of each delivery method along with strategies for sustained delivery of dsRNAs via fungal entomopathogen/endosymbiont or nontransgenic RNAi approaches, foliar sprays, root absorption or nanocarriers as well as the factors affecting efficient RNAi and their biosafety issues. Genome sequencing and transcriptome studies of whitefly species are facilitating the selection of appropriate genes for RNAi and gene-editing technology for the efficient and resilient management of whiteflies and their transmitted viruses.

Advances in the Development of Microbial Double-Stranded RNA Production Systems for Application of RNA Interference in Agricultural Pest Control

“…dsRNA production methods have been continuously optimized in recent years to adapt to production needs and promote the application of this technology. The cost of dsRNA was approximately US$12,000/g in 2008, dropping to US$60/g in 2018, and in 2020, RNAGri had the ability to produce tons of dsRNA at a cost of US$1/g, Greenlight’s GreenWorX ™ system can further reduce the cost of dsRNA synthesis to < US$0.5/g ( Cagliari et al, 2019 ; Suhag et al, 2020 ; Taning et al, 2020 ), which will provide material for the economical large-scale application of dsRNA-based pesticides.…”

Whitefly (Bemisia tabaci) Management (WFM) Strategies for Sustainable Agriculture: A Review

“…The use of dsRNA detoxification gene in transgenic Arabidopsis thaliana knocks-down the BtBGSTs5 gene in the gut of whiteflies, extends the nymph developmental time, and causes decline in B. tabaci densities [281]. Thus, there is a need for robust biotechnological interventions for sustainable management of whiteflies [282].…”

Current Scenario of Exogenously Induced RNAi for Lepidopteran Agricultural Pest Control: From dsRNA Design to Topical Application

“…In 2008, the cost of dsRNA was approximately US$12,000/g, dropping to US$60/g in 2018 [137]. RNAGri had the ability to produce tons of dsRNA at a cost of US$1/g, Greenlight's GreenWorX™ system can further reduce the cost of dsRNA synthesis to < US$0.5/g [50,[138][139][140][141]).…”