scholarly journals Inheritance of L1014F and M918T sodium channel mutations associated with pyrethroid resistance in Myzus persicae

2008 ◽  
Vol 4 (5) ◽  
pp. 545-548 ◽  
Author(s):  
Ioannis Eleftherianos ◽  
Stephen P Foster ◽  
Martin S Williamson ◽  
Ian Denholm
Keyword(s):  
Sodium Channel ◽  
Myzus Persicae ◽  
Pyrethroid Resistance ◽  
Pest Species ◽  
Pyrethroid Insecticides ◽  
Potato Aphid ◽  
Direct Dna Sequencing ◽  
Gene Segregation ◽  
Target Site Resistance ◽  
Peach Potato Aphid

Two amino acid substitutions (L1014F and M918T) in the voltage-gated sodium channel confer target-site resistance to pyrethroid insecticides in the peach potato aphid, Myzus persicae . Pyrethroid-resistant and -susceptible M. persicae clones with various combinations of these mutations were crossed under laboratory conditions, and the genotypes of aphid progeny were analysed by direct DNA sequencing of the IIS4–S6 region of the sodium channel gene. Segregation patterns showed that in aphids heterozygous for both L1014F and M918T, both mutations were present in the same resistance allele. Despite these mutations appearing largely recessive in other pest species, such aphids exhibited strong resistance to pyrethroids in leaf-dip bioassays. These results have important implications for the spread and management of pyrethroid resistance in field populations.

Characterization of the M918T sodium channel gene mutation associated with strong resistance to pyrethroid insecticides in the peach-potato aphid, Myzus persicae (Sulzer)

2007 ◽  
Vol 98 (2) ◽  
pp. 183-191 ◽  
Author(s):  
I. Eleftherianos ◽  
S.P. Foster ◽  
M.S. Williamson ◽  
I. Denholm
Keyword(s):  
Sodium Channel ◽  
Myzus Persicae ◽  
Pyrethroid Resistance ◽  
Type I ◽  
Pyrethroid Insecticides ◽  
Potato Aphid ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Wide Range ◽  
Peach Potato Aphid

AbstractRecent advances in the characterisation of insect sodium channel gene sequences have identified a small number of point mutations within the channel protein that are implicated in conferring target-site resistance to pyrethroid insecticides (so-called knockdown resistance or kdr). The L1014F (leucine-to-phenylalanine) mutation located in the centre of segment 6 of the domain II region (IIS6) of the sodium channel (the so-called kdr trait) has been detected in the peach-potato aphid, Myzus persicae (Sulzer), and is considered to be the primary cause of pyrethroid resistance in this species. Here we report on the characterisation of a second mutation, M918T (methione-to-threonine), within the nearby IIS4–S5 intracellular linker (the so-called super-kdr trait) in a field clone also possessing L1014F, with both mutations present in heterozygous form. The resistance phenotype of M. persicae clones possessing various combinations of L1014F and M918T to a wide range of pyrethroids (both Type I and II) was assessed in leaf-dip bioassays and to lambda-cyhalothrin applied at up to ten times the recommended field rate as foliar sprays to aphids feeding on whole plants. Bioassay results demonstrated that presence of both mutations was associated with extreme resistance to all the pyrethroids tested relative to aphids lacking the mutations. Furthermore, this resistance well exceeded that shown by aphids that were homozygous for L1014F but lacking M918T. However, pre-treatment with piperonyl butoxide in the leaf-dip bioassays failed to suppress pyrethroid resistance in aphids carrying one or both of the mutations. The relevance of these findings for monitoring and managing pyrethroid resistance in M. persicae populations in the field is discussed.

scholarly journals The evolution of insecticide resistance in the peach–potato aphid, Myzus persicae

1998 ◽  
Vol 353 (1376) ◽  
pp. 1677-1684 ◽  
Author(s):  
A. L. Devonshire ◽  
L. M. Field ◽  
S. P. Foster ◽  
G. D. Moores ◽  
M. S. Williamson ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Myzus Persicae ◽  
Temporal Dynamics ◽  
Diagnostic Methods ◽  
Strong Linkage Disequilibrium ◽  
Potato Aphid ◽  
Wide Range ◽  
Target Site Resistance ◽  
External Stimuli ◽  
Peach Potato Aphid

The peach–potato aphid Myzus persicae (Sulzer) can resist a wide range of insecticides, but until recently (1990) the only mechanism identified was the increased production of carboxylesterases (E4 or FE4), which cause enhanced degradation and sequestration of insecticidal esters. We have now identified two forms of target–site resistance involving changes in the acetylcholinesterase ( AChE ) and sodium channel ( kdr ) genes. Biochemical and DNA diagnostic methods can be used to identify all three mechanisms in individual aphids, and thereby establish their spatial distributions and temporal dynamics. Amplified genes underlie the increased production of esterases but their expression is modulated by DNA methylation. Amplification of the E4 gene is in strong linkage disequilibrium with the kdr mechanism. This may reflect strong insecticidal selection favouring aphids with multiple mechanisms, tight chromosomal linkage and/or the prominence of parthenogenesis in many M. persicae populations. The decreased fitness of resistant aphids under winter conditions may be a consequence of the altered sodium–channel gene affecting behaviour and/or the perception of external stimuli.

Temporal and spatial incidence of alleles conferring knockdown resistance to pyrethroids in the peach–potato aphid, Myzus persicae (Hemiptera: Aphididae), and their association with other insecticide resistance mechanisms

2007 ◽  
Vol 97 (3) ◽  
pp. 243-252 ◽  
Author(s):  
J.A. Anstead ◽  
J. Mallet ◽  
I. Denholm
Keyword(s):  
Myzus Persicae ◽  
Resistance Mechanisms ◽  
Pest Species ◽  
Knockdown Resistance ◽  
Potato Aphid ◽  
Strong Selection ◽  
Eastern Australia ◽  
Temporal And Spatial ◽  
The Uk ◽  
Peach Potato Aphid

AbstractThe peach–potato aphid, Myzus persicae (sulzer), is an important arable pest species throughout the world. Extensive use of insecticides has led to the selection of resistance to most chemical classes including organochlorines, organophosphates, carbamates and pyrethroids. Resistance to pyrethroids is often the result of mutations in the para-type sodium channel protein (knockdown resistance or kdr). In M. persicae, knockdown resistance is associated with two amino-acid substitutions, L1014F (kdr) and M918T (super-kdr). In this study, the temporal and spatial distributions of these mutations, diagnosed using an allelic discriminating polymerase chain reaction assay, were investigated alongside other resistance mechanisms (modified acetylcholinesterase (MACE) and elevated carboxylesterases). Samples were collected from the UK, mainland Europe, Zimbabwe and south-eastern Australia. The kdr mutation and elevated carboxylesterases were widely distributed and recorded from nearly every country. MACE and super-kdr were widespread in Europe but absent from Australian samples. The detection of a strongly significant heterozygote excess for both kdr and super-kdr throughout implies strong selection against individuals homozygous for these resistance mutations. The pattern of distribution found in the UK seemed to indicate strong selection against the super-kdr (but not the kdr) mutation in any genotype, in the absence of insecticide pressure. There was a significant association (linkage disequilibrium) between different resistance mechanisms, which was probably promoted by a lack of recombination due to parthenogenesis.

Intensification of insecticide resistance in UK field populations of the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae) in 1996

1998 ◽  
Vol 88 (2) ◽  
pp. 127-130 ◽  
Author(s):  
S.P. Foster ◽  
I. Denholm ◽  
Z.K. Harling ◽  
G.D. Moores ◽  
A.L. Devonshire
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Resistance Mechanism ◽  
The Novel ◽  
Potato Aphid ◽  
Aphid Control ◽  
Target Site Resistance ◽  
The Uk ◽  
First Time ◽  
Peach Potato Aphid

AbstractThe well-established carboxylesterase-based resistance to insecticides in Myzus persicae Sulzer has recently been accentuated by the appearance of aphids with a modified acetylcholinesterase (MACE) insensitive to pirimicarb and the novel aphicide, triazamate. This target site resistance mechanism was found in M. persicae from crops in the UK for the first time in 1996, together with especially large proportions of aphids with R2 and R3 levels of carboxylesterases, a combination that was associated with serious insecticide failures. This paper describes the incidence of both mechanisms and discusses the implications for future recommendations for aphid control in the UK.

scholarly journals The properties of a carboxylesterase from the peach-potato aphid, Myzus persicae (Sulz.), and its role in conferring insecticide resistance

1977 ◽  
Vol 167 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Alan L. Devonshire
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Order Rate Constant ◽  
Preliminary Evidence ◽  
Exchange Chromatography ◽  
Potato Aphid ◽  
First Order ◽  
Different Strains ◽  
Hydrolysis Of ◽  
Peach Potato Aphid

Carboxylesterases from different strains of Myzus persicae were examined to try to understand their contribution to insecticide resistance. Preliminary evidence that they are involved comes from the good correlation between the degree of resistance and the carboxylesterase and paraoxon-degrading activity in aphid homogenates. Furthermore the carboxylesterase associated with resistance could not be separated from the insecticide-degrading enzyme by electrophoresis or ion-exchange chromatography. Homogenates of resistant aphids hydrolysed paraoxon 60 times faster than did those of susceptible aphids, yet the purified enzymes from both sources had identical catalytic-centre activities towards this substrate and also towards naphth-1-yl acetate, the latter being hydrolysed by both 2×106 times faster than paraoxon. These observations provide evidence that the enzyme from both sources is identical, and that one enzyme hydrolyses both substrates. This was confirmed by relating the rate of paraoxon hydrolysis to the rate at which paraoxon-inhibited carboxylesterase re-activated. Both had the same first-order rate constant (0.01min−1), showing clearly that the hydrolysis of both substrates is brought about by the same enzyme. Its Km for naphth-1-yl acetate was 0.131mm, and for paraoxon 75pm. The latter very small value could not be measured directly, but was calculated from substrate-competition studies coupled with measurements of re-activation of the diethyl phosphorylated enzyme. Since the purified enzymes from resistant and susceptible aphids had the same catalytic-centre activity, the 60-fold difference between strains must be caused by different amounts of the same enzyme resulting from mutations of the regulator gene(s) rather than of the structural gene.

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