Deciphering the Pyrethroid Resistance Mechanism: Functional Insight into the Sodium Channel Auxiliary Subunits TipE and TEH1 in Myzus persicae

Pyrethroids target voltage-gated sodium channels (VGSCs), and their overuse readily leads to resistance. In this study, we cloned the auxiliary subunit genes TipE and TEH1 from green peach aphid Myzus persicae and found that their expression was significantly downregulated in a resistant field strain compared to a susceptible laboratory strain. Knockdown of Mp TipE and Mp TEH1 increased M. persicae resistance to bifenthrin and λ-cyhalothrin by 2.6- to 7.9-fold. Heterologous coexpression of MpTipE and MpTEH1 with sodium channels (BgNa v /DmNa v ) altered channel gating properties, and notably decreased sensitivity to four pyrethroids by 4.2- to 18.4-fold. These results demonstrate that auxiliary subunits modulate sodium channel sensitivity to pyrethroids, challenging the conventional paradigm that resistance arises solely from target-site mutations, and provide a new direction for research into pyrethroid resistance.