Molecular basis for the pheromone-mediated feeding preference of early-instar Mythimna separata larvae

Abstract

Insect sex pheromones are important chemical signals in sexual communication, they are traditionally thought to be inactive to larvae. However, it was found that some lepidopteran larvae can be significantly attracted by sex pheromones of the same species in a food context. Here we reported that the host-feeding choice of early-instar Mythimna separata larvae can be effectively regulated by the sex pheromone component (Z)-11-hexadecenal (Z11-16: Ald). Further exploration revealed that two olfactory proteins, M. separata general odorant binding protein 2 (MsGOBP2) and olfactory receptor 3 (MsOR3), were molecular basis of the host-feeding choice regulation mediated by Z11-16: Ald. Silencing either MsGOBP2 or MsOR3 led to a sharply reduced preference for Z11-16: Ald-spiked hosts. It is possible that the Z11-16: Ald-based preference of the M. separata larvae for host is governed by the interplay between MsGOBP2 and MsOR3. In the present research, the interactions between MsGOBP2 and Z11-16: Ald were also discussed using molecular dynamics-based approaches. Our research explored insight into the Z11-16: Ald-mediated host-feeding choice regulation of M. separata larvae, all the results would aid in developing olfaction-based methods for controlling pests in larval stage.

EsigGOBP1: The Key Protein Binding Alpha-Phellandrene in Endoclita signifer Larvae

“…In previous studies, results from behavior choice assays to the exposure of eucalyptus volatiles, showed that the 3rd and 5th instar larvae of E. signifer , were significantly attracted to only o-cymene and β-Pinene, respectively [ 33 , 34 ]. To determine whether EsigGOBP1 commonly perceive these GC-EAD active volatiles, we evaluated the binding affinities of recombinant protein EsigGOBP1 to these volatiles using the fluorescence competition binding assays (FCBA).…”

“…Notably, the sex pheromones of Plutella xylostella also work on attracting early-instar larvae to food sources, and they work only when the plant odorants coexist [ 32 ], which indicates an association between pheromone attraction and food source. GOBPs have been reported to show high expressions at the larval stage, where it binds to plant volatiles [ 33 ]; however, whether the GOBP in E. signifer larvae also bind to plant volatiles, to direct them to food sources is unknown.…”