Distribution of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mitotypes in Commercial Cotton Fields in the Punjab Province of Pakistan

Shah, Syed Hamid Jalal; Paredes‐Montero, Jorge R.; Malik, Amir Humayun; Brown, Judith K.; Qazi, Javaria

doi:10.1653/024.103.0407

Cited by 5 publications

(1 citation statement)

References 51 publications

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“…The B variant (MEAM1) causes extreme damages to field crops, in particular in irrigated agroecosystems in Egypt (Shaurub et al 2021), Pakistan (Shah et al 2020;Paredes-Montero et al 2021), and more largely in the Indian subcontinent, Sudan, and in Central and South America (Azab et al 1971;Brown and Bird 1992;Horowitz et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Predicting the insecticide-driven mutations in a crop pest insect: Evidence for multiple polymorphisms of acetylcholinesterase gene with potential relevance for resistance to chemicals

Renault

Elfiky

Mohamed

2022

Environ Sci Pollut Res

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The silverleaf whitefly Bemisia tabaci (Gennadius, 1889) (Homoptera: Aleyrodidae) is a serious invasive herbivorous insect pest worldwide. The misuse and excessive use of pesticides hasve progressively selected B. tabaci specimens, progressively reducing the effectiveness of the treatments, and ultimately ending in the selection of pesticide-resistantce strains. The management of this crop pest has thus become challenging owing to the high levels of resistance to all major classes of recommended insecticides, including organophosphates (OPs). Here, we used in silico techniques for detecting molecular mutations in ace1 gene from naturally occurring B. tabaci variants, and monitor the presence and frequency of the detected mutations from 30 populations of the silver whitefly from Egypt and Pakistan. We found several point mutations in ace1-type acetylcholinesterase (ace1) in the studied B. tabaci B variants (MEAM1) naturally occurring in the field. By comparing ace1 sequence data and point mutations with those reportedfrom on an organophosphate-susceptible and an organophosphate-resistant strains of B. tabaci (SUD-S), and to ace1 sequence data retrieved from GenBank for that species and to nucleotide polymorphisms from other arthropods, we identified novel mutations that could potentially influence insecticide resistance. Seven Egyptian field strains had 100% homology with the fragment of the Israeli B. tabaci susceptible allele (SUD-SUD), revealing a high conservation of the sequence/nucleotide, and/or possible missense mutations. We also report novel amino acid substitutions (S369W, C316W, P317G, and P317F) as likely candidates conferring resistance to organophosphates. Indeed, the location of these mutations, which we visualized on the 3D crystal structure of acetylcholinesterase, occur lose to the access of the active site gorge of the enzyme. The phylogenetic analysis revealed that these novel gene sequences appeared at the top of the clade in the tree, suggesting that the reported novel point mutations have evolved recentlyHomology modeling and molecular docking analyses were performed to determine if the mutation-induced changes in form 1 acetylcholinesterase (AChE1) structure could confer resistance to carbamate and organophosphate insecticides. Mutations had small effects on binding energy (ΔGb) interactions between mutant AChE1 and insecticides; they altered the conformation of the peripheral anionic site of AChE1, and modified the enzyme surface, and these changes have potential effects on the target-site sensitivity. Altogether, the results from this study provides information on genic variants of B. tabaci ace1 for future monitoring insecticide resistance development and report a potential case of environmentally driven gene variations.

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