Biochemical and Molecular Analysis of Field Resistance to Spirodiclofen in Panonychus citri (McGregor)

Abstract

Spirodiclofen is one of the most widely used acaricides in China. The citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), is one of the most destructive citrus pests worldwide and has developed a high resistance to spirodiclofen. However, the molecular mechanism of spirodiclofen resistance in P. citri is still unknown. In this study, we identified a field spirodiclofen-resistant strain (DL-SC) that showed 712-fold resistance to spirodiclofen by egg bioassay compared to the susceptible strain. Target-site resistance was not detected as non-synonymous mutations were not found by amplification and sequencing of the ACCase gene of resistant and susceptible strains; in addition, the mRNA expression levels of ACCase were similar in both resistant and susceptible strains. The activity of detoxifying enzymes P450s and CCEs in the resistant strain was significantly higher than in the susceptible strain. The transcriptome expression data showed 19 xenobiotic metabolisms genes that were upregulated. Stage-specific expression profiling revealed that the most prominent upregulated gene, CYP385C10, in transcriptome data was significantly higher in resistant strains in all stages. Furthermore, functional analysis by RNAi indicated that the mortality caused by spirodiclofen was significantly increased by silencing the P450 gene CYP385C10. The current results suggest that overexpression of the P450 gene, CYP385C10, may be involved in spirodiclofen resistance in P. citri.

Identification and Functional Characterization of an Omega-Class Glutathione S-Transferase Gene PcGSTO1 Associated with Cyetpyrafen Resistance in Panonychus citri (McGregor)

“…Similarly, CYP385C10, which is associated with spirodiclofen resistance, was detected as upregulated during the egg, nymph, and adult stage in spirodiclofen-resistant strain of P. citri. 39 Compared with the nymph and adult stage, PcGSTO1 is upregulated in the egg stage with the highest level. It might be due to the fact that the enhanced ability to escape and the thicker The expression level of PcGSTO1 was markedly enhanced by 2.16 and 6.28 fold after 24 h of treatment with LC 30 and LC 50 cyetpyrafen, respectively.…”

“…Similarly, CYP385C10 , which is associated with spirodiclofen resistance, was detected as upregulated during the egg, nymph, and adult stage in spirodiclofen-resistant strain of P. citri . Compared with the nymph and adult stage, PcGSTO1 is upregulated in the egg stage with the highest level.…”

“…According to currently reported literature, citrus red mite has developed various degrees of resistance to many commonly used acaricides. 6,39 Cyetpyrafen is a newly developed product of mitochondrial complex II electron transport inhibitors launched in 2017. 7 T. urticae has been monitored moderate level of cyetpyrafen resistance in the field population in different regions of China.…”

“…citri can quickly develop resistance to acaricides. According to currently reported literature, citrus red mite has developed various degrees of resistance to many commonly used acaricides. , Cyetpyrafen is a newly developed product of mitochondrial complex II electron transport inhibitors launched in 2017 T.…”

Knockdown of the ABCG23 Gene Disrupts the Development and Lipid Accumulation of Panonychus citri (Acari/Tetranychidae)

“…Panonychus citri McGregor (Acari/Tetranychidae) is a highly destructive agricultural pest that is commonly controlled through the use of chemical insecticides [22][23][24]. One of these insecticides is spirobudiclofen, a tetronic acid derivative, acaricide, that targets lipid biosynthesis.…”