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Molecular mechanisms of Tetranychus urticae chemical adaptation in hop fields.

Piraneo TG, Bull J, Morales MA, Lavine LC, Walsh DB, Zhu F - Sci Rep (2015)

Bottom Line: Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population.However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance.Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

View Article: PubMed Central - PubMed

Affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.

ABSTRACT
The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

No MeSH data available.


Related in: MedlinePlus

Relative expression of CYP385C4, CYP389A1 and CYP392D8 in field T. urticae populations compared with that of the susceptible strain.The mRNA levels were quantified by qRT-PCR and normalized with reference genes Actin and RP49. The data shown are mean + SEM (n = 3). Statistical significance of the gene expression between two samples was calculated using Student’s t test (two-tailed distribution). *p-value < 0.05, **p-value < 0.01.
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f5: Relative expression of CYP385C4, CYP389A1 and CYP392D8 in field T. urticae populations compared with that of the susceptible strain.The mRNA levels were quantified by qRT-PCR and normalized with reference genes Actin and RP49. The data shown are mean + SEM (n = 3). Statistical significance of the gene expression between two samples was calculated using Student’s t test (two-tailed distribution). *p-value < 0.05, **p-value < 0.01.

Mentions: Besides target site insensitivity, cytochrome P450-mediated detoxification had been shown to be one of the most important mechanisms in acaricide resistance of T. urticae373839. The genome of T. urticae contains 86 P450 genes. We examined the relative expression of three P450s, CYP385C4, CYP389A1, and CYP392D8, belonging to the CYP3, CYP4, and CYP2 clans, respectively. We chose these three P450s because they have been shown to exhibit more than two-fold up regulation after switching host plants and their expression patterns have been linked to acaricide resistance in T. urticae9. The expressions of these three P450s in five field populations from five major locations were compared with their expressions in the susceptible population. As shown in Fig. 5, CYP385C4 had significantly higher expression in all five field populations. However, this increase in expression was not large (less than two-fold). CYP389A1 only showed significantly higher expression in the Prosser 2 population. The expression of CYP392D8 was strikingly higher in all five field populations, exhibiting levels 5 to 40-fold higher than the susceptible strain. It indicates that CYP392D8 may play an important role in acaricide resistance of T. urticae populations in hopyards.


Molecular mechanisms of Tetranychus urticae chemical adaptation in hop fields.

Piraneo TG, Bull J, Morales MA, Lavine LC, Walsh DB, Zhu F - Sci Rep (2015)

Relative expression of CYP385C4, CYP389A1 and CYP392D8 in field T. urticae populations compared with that of the susceptible strain.The mRNA levels were quantified by qRT-PCR and normalized with reference genes Actin and RP49. The data shown are mean + SEM (n = 3). Statistical significance of the gene expression between two samples was calculated using Student’s t test (two-tailed distribution). *p-value < 0.05, **p-value < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664861&req=5

f5: Relative expression of CYP385C4, CYP389A1 and CYP392D8 in field T. urticae populations compared with that of the susceptible strain.The mRNA levels were quantified by qRT-PCR and normalized with reference genes Actin and RP49. The data shown are mean + SEM (n = 3). Statistical significance of the gene expression between two samples was calculated using Student’s t test (two-tailed distribution). *p-value < 0.05, **p-value < 0.01.
Mentions: Besides target site insensitivity, cytochrome P450-mediated detoxification had been shown to be one of the most important mechanisms in acaricide resistance of T. urticae373839. The genome of T. urticae contains 86 P450 genes. We examined the relative expression of three P450s, CYP385C4, CYP389A1, and CYP392D8, belonging to the CYP3, CYP4, and CYP2 clans, respectively. We chose these three P450s because they have been shown to exhibit more than two-fold up regulation after switching host plants and their expression patterns have been linked to acaricide resistance in T. urticae9. The expressions of these three P450s in five field populations from five major locations were compared with their expressions in the susceptible population. As shown in Fig. 5, CYP385C4 had significantly higher expression in all five field populations. However, this increase in expression was not large (less than two-fold). CYP389A1 only showed significantly higher expression in the Prosser 2 population. The expression of CYP392D8 was strikingly higher in all five field populations, exhibiting levels 5 to 40-fold higher than the susceptible strain. It indicates that CYP392D8 may play an important role in acaricide resistance of T. urticae populations in hopyards.

Bottom Line: Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population.However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance.Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

View Article: PubMed Central - PubMed

Affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.

ABSTRACT
The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

No MeSH data available.


Related in: MedlinePlus