Transgenic Expression of dsRNA Targeting the Pentalonia nigronervosa acetylcholinesterase Gene in Banana and Plantain Reduces Aphid Populations

Abstract

The banana aphid, Pentalonia nigronervosa, is the sole insect vector of banana bunchy top virus (BBTV), the causal agent of banana bunchy top disease. The aphid acquires and transmits BBTV while feeding on infected banana plants. RNA interference (RNAi) enables the generation of pest and disease-resistant crops; however, its effectiveness relies on the identification of pivotal gene sequences to target and silence. Acetylcholinesterase (AChE) is an essential enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine in animals. In this study, the AChE gene of the banana aphid was targeted for silencing by RNAi through transgenic expression of AChE dsRNA in banana and plantain plants. The efficacy of dsRNA was first assessed using an artificial feeding assay. In vitro aphid feeding on a diet containing 7.5% sucrose, and sulfate complexes of trace metals supported aphid growth and reproduction. When AChE dsRNA was included in the diet, a dose of 500 ng/μL was lethal to the aphids. Transgenic banana cv. Cavendish Williams and plantain cvs. Gonja Manjaya and Orishele expressing AChE dsRNA were regenerated and assessed for transgene integration and copy number. When aphids were maintained on elite transgenic events, there was a 67.8%, 46.7%, and 75.6% reduction in aphid populations growing on Cavendish Williams, Gonja Manjaya, and Orishele cultivars, respectively, compared to those raised on nontransgenic control plants. These results suggest that RNAi targeting an essential aphid gene could be a useful means of reducing both aphid infestation and potentially the spread of the disease they transmit.

The role of insect vector Pentalonia nigronervosa in spreading banana bunchy top disease in South Sumatera

“…Based on research, banana cultivars that have AA and AB genomes were most favored by P. nigronervosa [25]. In transmitting banana dwarf disease, P. nigronervosa secretes viruses inhaled simultaneously with infected fluids when this insect feeds [20]. Viruses inhaled by P. nigronervosa enter the gut of the insect.…”

RNA‐dependent RNA polymerase could extend the lasting validity period of exogenous dsRNA

“…Although dsRNA derivatives are synthesized in cytoplasm and aphids are phloem feeders, and we have not found direct proof for dsRNA transmission from cytoplasm to phloem in plants, the following facts indicate its possibility. Many reports have shown that the dsRNA synthesized by transgenic crops is efficient at triggering RNAi in phloem feeder pests 72–75 . This might indicate that there is sufficient dsRNA transmitted from plant cells to phloem to dose these pests.…”

“…Many reports have shown that the dsRNA synthesized by transgenic crops is efficient at triggering RNAi in phloem feeder pests. [72][73][74][75] This might indicate that there is sufficient dsRNA transmitted from plant cells to phloem to dose these pests. In addition, the mRNAs of host plants (cucumbers) have been detected in a phloem feeder (green peach aphid) feeding on them, which proves that the mRNA synthesized in plant cells could transmit to phloem.…”

Disruption of transmission of plant pathogens in the insect order Hemiptera using recent advances in RNA interference biotechnology

“…The banana aphid, Pentalonia nigronervosa , is the sole insect vector of banana bunchy top virus, the causal agent of banana bunchy top disease. RNAi in P. nigronervosa , resulted in increased insect mortality by targeting the acetylcholinesterase (AChE) gene for silencing through transgenic expression of AChE dsRNA in banana and plantain plants (Jekayinoluwa et al, 2021). AChE is an essential enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine in animals.…”