State Key Laboratory of Rice Biology, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Key Laboratory of State Forestry Administration on Bamboo Resources and Utilization, China National Bamboo Research Center, Hangzhou, China.
Plant Cell Environ. 2020 Jul;43(7):1740-1750. doi: 10.1111/pce.13747. Epub 2020 Mar 14.
When attacked by herbivores, plants emit volatiles to attract parasitoids and predators of herbivores. However, our understanding of the effect of plant volatiles on the subsequent behaviour of conspecific parasitoids when herbivores on plants are parasitized is limited. In this study, rice plants were infested with gravid females of the brown planthopper (BPH) Nilaparvata lugens for 24 hr followed by another 24 hr in which the BPH eggs on plants were permitted to be parasitized by their egg parasitoid, Anagrus nilaparvatae; volatiles from rice plants that underwent such treatment were less attractive to subsequent conspecific parasitoids compared to the volatiles from plants infested with gravid BPH females alone. Chemical analysis revealed that levels of JA and JA-Ile as well as of four volatile compounds-linalool, MeSA, α-zingiberene and an unknown compound-from plants infested with BPH and parasitized by wasps were significantly higher than levels of these compounds from BPH-infested plants. Laboratory and field bioassays revealed that one of the four increased chemicals-α-zingiberene-reduced the plant's attractiveness to the parasitoid. These results suggest that host plants can fine-tune their volatiles to help egg parasitoids distinguish host habitats with parasitized hosts from those without.
当受到食草动物的攻击时，植物会释放挥发性物质来吸引食草动物的寄生蜂和捕食者。然而，我们对植物挥发性物质对寄生在植物上的食草动物被寄生后同种寄生蜂后续行为的影响的理解是有限的。在这项研究中，水稻植株被怀有身孕的褐飞虱（BPH）Nilaparvata lugens 雌虫侵袭 24 小时，然后再让这些 BPH 卵在植物上被其卵寄生蜂 Anagrus nilaparvatae 寄生 24 小时；与单独被怀有身孕的 BPH 雌虫侵袭的植物的挥发性物质相比，经历这种处理的植物的挥发性物质对随后的同种寄生蜂的吸引力降低。化学分析显示，JA 和 JA-Ile 的水平以及四种挥发性化合物——芳樟醇、MeSA、α-姜烯和一种未知化合物——从被 BPH 侵袭并被黄蜂寄生的植物中的水平明显高于从被 BPH 侵袭的植物中的水平。实验室和野外生物测定显示，四种增加的化学物质之一——α-姜烯——降低了植物对寄生蜂的吸引力。这些结果表明，宿主植物可以微调它们的挥发性物质，以帮助卵寄生蜂区分有寄生宿主的宿主栖息地和没有寄生宿主的栖息地。
