Novel mutations and expression changes of acetyl‐coenzyme A carboxylase are associated with spirotetramat resistance in Aphis gossypii Glover

Abstract

Acetyl-coenzyme A carboxylase (ACC) catalyses the carboxylation of acetyl-coenzyme A (acetyl-CoA) to produce malonyl-CoA during the de novo synthesis of fatty acids. Spirotetramat, an inhibitor of ACC, is widely used to control a range of sucking insects, including the Aphis gossypii. In the present study, Reverse transcription quantitative real-time PCR (RT-qPCR) results demonstrated that ACC was significantly overexpressed in a laboratory-selected spirotetramat-resistant strain compared with the susceptible strain. ACC RNA interference significantly suppressed fecundity and led to cuticle formation deficiencies in resistant adults and nymphs compared with the control. The full-length ACC gene was sequenced from both resistant and susceptible cotton aphids, and a strong association was found between spirotetramat resistance and 14 amino acid substitutions in the biotin carboxylase domain and carboxyl transferase domain of the ACC gene. Furthermore, ACC activity was higher in resistant aphids than in the susceptible strain, and ACC in the resistant aphids exhibited significant insensitivity to spirotetramat and spirotetramat-enol. The results indicate that the overexpressed insensitive (mutated) ACC target played an important role in the high levels of spirotetramat resistance observed here. This association of amino acid substitution with resistance is the first report of a potential target site mechanism affecting spirotetramat in the cotton aphid.

Impact of the secondary plant metabolite Cucurbitacin B on the demographical traits of the melon aphid, Aphis gossypii

“…To control this pest in such crops, several insecticides have been developed and adopted into Integrated Pest Management (IPM) packages worldwide 30 – 33 . However, the use of insecticides has some drawbacks, which are known for their potential side effects on non-target organisms 34 , such as aphid natural enemies 35 , 36 , and for the development of insecticide resistance in aphids 37 , 38 . Therefore, non-chemical control strategies, such as biological control 39 – 41 , biopesticides 42 , 43 , and plant resistance should be prioritized for the sustainable control of aphid pests.…”

Functional investigation of lncRNAs and target cytochrome P450 genes related to spirotetramat resistance in Aphis gossypii Glover

“…However, little is known of the molecular basis of this resistance. 46,49,50 Mechanisms of resistance to insecticides are associated with ACC gene mutations [60][61][62] or enhanced detoxification, such as P450 genes 49,50 or uridine diphosphate-glycosyltransferases (UDP-UGTs). 63 For example, our previous work showed that high expression of the P450 genes CYP380C6, CYP4CJ1, CYP6DA2, CYP6CY7 and CYP6CY21 is involved in resistance to cyantraniliprole in A. gossypii.…”

Empowering Australian insecticide resistance research with genetic information: the road ahead

“…RNAi and CRISPR/Cas9 can then be used to validate the functional roles of alleles hypothesised to be involved in resistance (Pan et al . 2017; Wang et al . 2017; Wang et al .…”

“…Transcriptomics and genome-wide associations can be used to correlate molecular variation and resistance phenotypes (Bass et al 2013;Tay et al 2015;Walsh et al 2018;Wybouw et al 2019). RNAi and CRISPR/Cas9 can then be used to validate the functional roles of alleles hypothesised to be involved in resistance (Pan et al 2017;Wang et al 2017;Wang et al 2018;Guest et al 2019). A priori candidate genes can be incorporated into genomic pipelines, but a large benefit of genomic approaches is that they provide scope to assess the role of genes without pre-existing expectations of their contribution to resistance.…”