Nonanal modulates oviposition preference in female Helicoverpa assulta (Lepidoptera: Noctuidae) via the activation of peripheral neurons

Abstract

BACKGROUND The insect olfactory system can recognize odorants for feeding, courtship, oviposition and avoiding natural enemies. Odorant cues from host plants play important roles in insect behaviours. Tobacco ( Nicotiana tabacum ) is the main cultivated host of the oriental tobacco budworm Helicoverpa assult . Volatiles of tobacco plants attract and stimulate oviposition in female moths. However, it is still not known how female H. assulta recognize tobacco volatiles and which odorant compounds are used as oviposition cues. RESULTS We detected 14 volatile compounds emitted from a tobacco plant during vegetative growth, using gas chromatography–mass spectrometry. Electroantennogram tests indicated that eight of the 14 compounds induced responses in female H. assulta. Among these eight volatiles, nonanal greatly increased oviposition preference. Single‐sensillum recording (SSR) results showed that many neurons housed in three types of short basiconic sensilla and four types of long basiconic sensilla responded to nonanal and heptanal as its structural analogue. The responses to nonanal were significantly stronger than those to the other compounds. Nonanal was the main ligand of OR67, an odorant receptor from H. assulta . This was demonstrated using an in vitro Xenopus oocytes expression system that supported the SSR results. CONCLUSION Nonanal is a key signal volatile of tobacco plants that attracts female H. assulta moths to oviposit. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Binding Affinity Characterization of Four Antennae-Enriched Odorant-Binding Proteins From Harmonia axyridis (Coleoptera: Coccinellidae)

“…Linalyl acetate is a monoterpene ester, which can be isolated from essential oils of Chrysactinia mexicana , Lavandula angustifolia , and Thymus leptophyllus ( Jan et al, 2016 ). In addition, the common volatile compound nonanal can attract female Grapholitha molesta in Y-tube experiment and is a critical volatile of tobacco for attracting female Helicoverpa assulta ( Lu and Qiao, 2020 ; Wang et al, 2020a ).…”

Odorant Receptor PxylOR11 Mediates Repellency of Plutella xylostella to Aromatic Volatiles

“…These same compounds induce different behavioral responses in different herbivores. For example, nonanal has an oviposition repellent effect on O. furnacalis , but an oviposition attractant effect on H. assulta ( Wang C. et al, 2020 ; Yu et al, 2020 ). All these suggest that benzyl alcohol, salicylaldehyde, and phenylacetaldehyde may play important roles in the interaction between host plants, P. xylostella , and natural enemies.…”

“…Large numbers of general ORs have important functions ( Liu et al, 2014 ; Zhang et al, 2016 ; Zhang et al, 2017 ). For instance, HassOR67 plays a key role in the recognition of nonanal, an ovipositional cue for H. assulta ( Wang C. et al, 2020 ). In Eupeodes corollae , general EcorOR25 is tuned to floral scent volatiles (eugenol and methyl eugenol), which is an attractant for adult male and female of E. corollae ( Li et al, 2020 ).…”

Trichoderma Strains and Metabolites Selectively Increase the Production of Volatile Organic Compounds (VOCs) in Olive Trees

“…Nonanal inhibits Penicillium cyclopium and Botrytis cinerea ’s mycelial growth by disrupting the fungal cell membrane’s integrity, leaking the cell constituents and potassium ions, enhancing the extracellular pH, the total lipid content, and the membrane permeability [ 53 , 54 ]. Moreover, the nonanal acts as an attractant for pollinators [ 55 ], is an antifeedant [ 56 ], and controls, via the activation of peripheral neurons (e.g., in Helicoverpa assulta ), the insect oviposition preference [ 57 ]. Finally, nonanal has anti-diarrheal properties on humans [ 58 ].…”