Increased expression of an isoform of the long non-coding RNA, lnc37707, is associated with malathion resistance in Bactrocera dorsalis

Abstract

The oriental fruit fly, Bactrocera dorsalis (Hendel) is an invasive pest threatening global fruit industries. Field populations of B. dorsalis exhibit complex insecticide resistance, hindering pest control efforts and exacerbating damage. Long non-coding RNAs (lncRNAs) are critical regulators of multiple bioprocess in insects, including insecticide resistance, and have potentials as novel target for pest management. Here, the candidate lncRNAs associated with malathion resistance in B. dorsalis were identified through RNA-seq. One of the isoforms of lnc37707, designated as lnc37707.10, was significantly enriched in the detoxification tissues of malathion-resistant (MR) strain. A specific fragment of lnc37707.10 (sflnc37707) was strongly associated with malathion resistance, and silencing sflnc37707 increased the susceptibility, whereas overexpressing it decreased susceptibility to malathion. Silencing sflnc37707 resulted in the down-regulation of 248 genes, but none of them included the four adjacent genes as its potential target. Instead, pathway analysis revealed significant enrichment of down-regulated genes involved in drug and xenobiotics metabolism, including P450s and GSTs. Bioinformatic analysis suggested a potential regulatory role of miRNA in the function of lnc37707. Further combining silence or overexpression sflnc37707 with miRNA mimic treatment identified that BdGSTd10 (an important gene involved in malathion resistance) and miR-1000 was strongly linked to lnc37707.10. Finally, a ceRNA (competing endogenous RNA) regulatory axis was proposed, where lnc37707.10 might indirectly modulate BdGSTd10 by sponging miR-1000 to regulate the malathion resistance in B. dorsalis. These findings provide a new insight into insecticide resistance and a potential lncRNA target for the sustainable pest management.