Investigation into the docking of odorant binding proteins from tea green leafhoppers with host plant volatile components

Insects possess an intricate and efficient olfactory system that plays a critical role in navigating their environment, facilitating host location, defensive maneuvers, and reproductive behaviors. In the present study, 12 biological samples were successfully sequenced, yielding a total of 79.92 G data. This led to the assembly of 46,291 Unigenes, with a cumulative length of 47,102,395 base pairs. These Unigenes were subsequently annotated across seven functional databases, including NR (22,104), Swissprot (16,203), KEGG (7,652), KOG (14,597), eggNOG (19,129), GO (14,852), and Pfam (15,267). Central to our findings, 33 genes associated with olfaction were identified, comprising 16 odorant binding proteins (OBPs), 13 chemosensory proteins (CSPs), 3 ionotropic receptors (IRs), and 1 sensory neuron membrane protein (SNMP). Given the critical role of volatile organic compounds emitted by ancient tea leaves in host plant location, the volatile components of these trees using HS-SPEM-GC-MS were further analyzed. The primary volatile identified were alcohols, aldehydes, esters, alkanes, olefins, ketones, and nitriles, with linalool (14.02%), (E)-hexenal (2.84%), and α-farnesene (6.75%) emerging as the predominant compounds. To understand the molecular interactions underlying the recognition of these compounds, molecular docking simulations were conducted, focusing on the three aforementioned compounds and three specific OBPs (OBP3, OBP4, and OBP7) from the tea green leafhoppers. Notably, α-farnesene exhibited the highest binding affinity with OBP7, with the binding process stabilized by the synergistic effects of hydrophobic and hydrogen bonding forces. These findings deepen our understanding of the olfactory recognition mechanisms employed by tea green leafhoppers in their interaction with ancient tea plants.