Data from: Feeding-induced rearrangement of green leaf volatiles reduces moth oviposition

The ability to decrypt volatile plant signals is essential if herbivorous insects are to optimize their choice of host plants for their offspring. Green leaf volatiles (GLVs) constitute a widespread group of defensive plant volatiles that convey a herbivory-specific message via their isomeric composition: feeding of the tobacco hornworm Manduca sexta converts (Z)-3- to (E)-2-GLVs thereby attracting predatory insects. Here we show that this isomer-coded message is monitored by ovipositing M. sexta females. We detected the isomeric shift in the host plant Datura wrightii and performed functional imaging in the primary olfactory center of M. sexta females with GLV structural isomers. We identified two isomer-specific regions responding to either (Z)-3- or (E)-2-hexenyl acetate. Field experiments demonstrated that ovipositing Manduca moths preferred (Z)-3-perfumed D. wrightii over (E)-2-perfumed plants. These results show that (E)-2-GLVs and/or specific (Z)-3/(E)-2-ratios provide information regarding host plant attack by conspecifics that ovipositing hawkmoths use for host plant selection.

若植食性昆虫要为后代优化寄主植物的选择，解析植物挥发性信号的能力至关重要。绿叶挥发性物质（Green leaf volatiles，GLVs）是一类分布广泛的防御性植物挥发性物质，可通过其异构体组成传递植食特异性信号：烟草天蛾（Manduca sexta）取食寄主植物后，会将(Z)-3-型GLVs转化为(E)-2-型GLVs，从而吸引捕食性昆虫。本研究发现，这种由异构体编码的信号可被产卵期的雌性烟草天蛾感知。我们在寄主植物武氏曼陀罗（Datura wrightii）中检测到了该异构体转化现象，并针对GLV结构异构体，对雌性烟草天蛾的初级嗅觉中枢开展了功能成像实验。我们鉴定出两个对异构体具有特异性响应的区域，分别响应(Z)-3-己烯乙酸酯与(E)-2-己烯乙酸酯。田间试验结果表明，相较于喷施(E)-2-型GLVs的植株，产卵期烟草天蛾更倾向于在喷施(Z)-3-型GLVs的武氏曼陀罗植株上产卵。上述研究结果证实，(E)-2-型GLVs和/或特定的(Z)-3/(E)-2比例，可传递寄主植物被同种昆虫侵害的相关信息，供产卵天蛾在选择寄主植物时参考。