Identification of a point mutation in the ace1 gene of Therioaphis trifolli maculata and detection of insecticide resistance by a diagnostic PCR-RFLP assay.
Aphids are important agricultural pests worldwide. Their control is largely based on chemical insecticides. One species that shows important invasive abilities and host-plant-related differences is Therioaphis trifolii (Monell) (Hemiptera: Aphididae). T. trifolii maculata, also known as spotted alfalfa aphid (SAA), can be very injurious to alfalfa crops in certain regions, such as in Saudi Arabia for effective control it is essential to diagnose and monitor the resistance mechanisms in the SAA populations. In the present study, we analysed acetylcholinesterase (ace) target site insensitivity mechanisms. A 650 bp length DNA containing the putative acetylcholinesterase (ace1) precursor was obtained and compared with other Hemipteran species. The sequences of many individual aphids collected from alfalfa crops in Saudi Arabia were analysed for the presence of resistance mutations: no resistance mutations were found at the resistance mutation loci 302; however, the presence of a serine-phenylalanine substitution (S431F) was identified in one individual. The S431F substitution, has been shown to confer significant levels of both organophosphate and carbamate resistance in other aphid species, and is now found for the first time in T. trifolii. We subsequently developed a simple polymerase chain reaction-restriction fragment length polymorphism assays for the S431F mutation, using a TaqI restriction site destroyed by the S431F mutation. The novel diagnostic assay may support the implementation of Insecticide Resistance Management strategies, for the control of SAA in alfalfa crops in the Kingdom of Saudi Arabia, and other countries worldwide.
Zoology Department,King Saud University,Kingdom of Saudi Arabia.
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AlSuhaibani
Department of Biochemistry and Biotechnology,University of Thessaly,41221 Larissa,Greece.
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Voudouris
Animal production Department,King Saud University,Kingdom of Saudi Arabia.
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Al-Atiyat
Department of Biochemistry and Biotechnology,University of Thessaly,41221 Larissa,Greece.
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Kotzamumin
Institute of Molecular Biology and Biotechnology,Foundation for Research and Technology-Hellas,73100 Heraklion,Greece.
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Vontas
Zoology Department,King Saud University,Kingdom of Saudi Arabia.
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Margaritopoulos
D000110:Acetylcholinesterase / Q000737:chemistry / Q000235:genetics*; D000818:Animals; D001042:Aphids / Q000235:genetics*; D004252:DNA Mutational Analysis; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D020539:Sequence Analysis, Protein
D019476:Insect Proteins; D000110:Acetylcholinesterase
Integrated Pest Management; alfalfa; insecticide resistance; spotted alfalfa aphid