Evolutionarily conserved odorant-binding proteins participate in establishing tritrophic interactions

Ruinan Yang; Dongzhen Li; Shancheng Yi; Manqun Wang

doi:10.1016/j.isci.2022.104664

Evolutionarily conserved odorant-binding proteins participate in establishing tritrophic interactions

iScience. 2022 Jun 23;25(7):104664. doi: 10.1016/j.isci.2022.104664. eCollection 2022 Jul 15.

Authors

Ruinan Yang¹, Dongzhen Li^{1

2}, Shancheng Yi¹, Manqun Wang¹

Affiliations

¹ Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
² Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China.

Abstract

Attracting herbivores and their natural enemies is a standard method where plant volatiles mediate tritrophic interactions. However, it remains unknown whether the shared attraction has a shared chemosensory basis. Here we focus on the odorant-binding proteins (OBPs), a gene family integral to peripheral detection of odoriferous chemicals. Previous evidence suggests that the herbivorous beetle Monochamus alternatus and its parasitoid beetle Dastarcus helophoroides are attracted to stressed pines. In this study, (+)-fenchone, emitted by stressed pines, is found to be attracted to M. alternatus and D. helophoroides in behavioral assays. Meanwhile, two orthologous OBPs with a slower evolutionary rate, respectively, from the two insects are shown to bind with (+)-fenchone, and the attraction is abolished after RNAi. These results show the ability of evolutionarily conserved OBPs from herbivores and their enemies to detect the same plant volatiles, providing an olfactory mechanism of chemical signals-mediated tritrophic relationships.

Keywords: Biochemistry; Evolutionary biology; Phylogenetics.