Molecular basis of Fenazaquin resistance in Polyphagotarsonemus latus revealed by transcriptome profiling and real-time validation.

Abstract

The broad mite, Polyphagotarsonemus latus (Banks), is a highly polyphagous tarsonemid pest that causes severe damage to a wide range of agricultural and horticultural crops. The excessive and indiscriminate use of Fenazaquin, a mitochondrial electron transport inhibitor, resulted in the rapid development of resistance in P. latus. To elucidate the molecular mechanisms underlying acaricide resistance, a transcriptomic investigation was conducted on Fenazaquin-resistant (FEN-SEL) and susceptible (NBAIR-GR-TAR-01a) populations. The analysis identified putative genes involved in detoxification, including cytochrome P450 monooxygenases (CYPs), glutathione S-transferases (GSTs), choline and carboxyl esterases (CCEs), and ATP-binding cassette (ABC) transporters. Phylogenetic analysis revealed lineage-specific expansions of clan 3 CYPs, delta and acari-specific mu classes of GSTs, and ABCC, ABCG, and ABCH subfamilies of ABC transporters. Ten resistance-associated unigenes were validated using quantitative real-time PCR to assess gene expression patterns. The results showed significant upregulation of CYP4CL3, CYP4CF4, two delta-class GSTs, two CCEs belonging to clade J″, and two ABC transporters from subfamily C. However, CYP4725A2 and CYP4726A1 showed downregulation. These findings highlight the potential association of multiple metabolism-related gene families with Fenazaquin resistance and their possible contribution to the resistant phenotype. Overall, this study provides molecular insights into Fenazaquin resistance in P. latus, supporting the need for targeted resistance management strategies. Further research is warranted to evaluate the potential of these genes as molecular targets for sustainable broad mite management.