Insecticide toxicity associated with detoxification enzymes and genes related to transcription of cuticular melanization among color morphs of Asian citrus psyllid

AbstractThe Asian citrus psyllid (Diaphorina citri Kuwayama) is known to exhibit abdominal color polymorphisms. In the current study, susceptibility to four insecticides was compared among orange/yellow, blue/green and gray/brown color morphs of field collectedD. citri. The LD50 values and 95% fiducial limits were quantified for each insecticide and color morph combination and ranged between 0.10 ng/ μL (0.06–0.10) and 6.16 ng/μL (3.30–12.50). Second, we measured the detoxification enzyme activity levels of orange/yellow, blue/green and gray/brown color morphs for cytochrome P450, glutathioneS‐transferase, and general esterase. The mean P450 activity (equivalent units) was significantly lower in gray/brown (0.152 ± 0.006) and blue/green morphs (0.149 ± 0.005) than in the orange/yellow morphs (0.179 ± 0.008). GST activity (μmol/min/mg protein) was significantly lower in the orange/y ellow morph (299.70 ±1.24) than gray/brown (350.86 ± 1.19) and blue/green (412.25 ± 1.37) morphs. The mean EST activity (μmol/min/mg protein) was significantly higher in blue/green (416.72 ± 5.12) and gray/brown morphs (362.19 ± 4.69) than in the orange/yellow morphs (282.56 ± 2.93). Addition ally, we analyzed the relative expression of assortment genes involved in cuticular melanization and basal immunity. The transcripts ofDopa Decarboxylase andTyrosine Hydroxylase were expressed higher in blue/green and gray/brown than orange/yellow morphs. The transcription results paralleled...

Source: Insect Science - April 19, 2018 Category: Biology Authors: Xue Dong Chen, Torrence A. Gill, Chi D. Nguyen, Nabil Killiny, Kirsten S. Pelz ‐Stelinski, Lukasz L. Stelinski Tags: ORIGINAL ARTICLE Source Type: research