University of Amsterdam, Department of Plant Physiology, Amsterdam, The Netherlands.
Phytochemistry. 2011 Jan;72(1):68-73. doi: 10.1016/j.phytochem.2010.10.014. Epub 2010 Nov 11.
How whiteflies (Bemisia tabaci) make the choice for a host plant prior to landing, is not precisely known. Here we investigated whether they respond to specific volatiles of tomato. Zingiberene and curcumene were purified from Solanum habrochaites (PI127826), characterised by NMR and X-ray analysis and identified as 7-epizingiberene and R-curcumene. In contrast, oil from Zingiber officinalis contained the stereoisomers zingiberene and S-curcumene, respectively. Using a combination of free-choice bio-assays and electroantennography, 7-epizingiberene and its dehydrogenated derivative R-curcumene were shown to be active as semiochemicals to B. tabaci adults, whereas the stereoisomers from ginger were not. In addition, R-curcumene elicited the strongest electroantennographic response. Bio-assays showed that a cultivated tomato could be made less attractive to B. tabaci than its neighbouring siblings by the addition of the tomato stereoisomer 7-epizingiberene or its derivative R-curcumene. These sesquiterpenes apparently repel adult whiteflies prior to landing, presumably because it informs them that after landing they, or their offspring, may be exposed to higher and lethal concentrations of the same compounds.
烟粉虱（Bemisia tabaci）在降落前选择宿主植物的机制尚不清楚。本研究调查了它们是否对番茄的特定挥发物做出反应。从 Solanum habrochaites（PI127826）中纯化出姜烯和莪术烯，通过 NMR 和 X 射线分析进行了表征，并鉴定为 7-表姜烯和 R-莪术烯。相比之下，生姜油中分别含有姜烯和 S-莪术烯的立体异构体。通过自由选择生物测定和触角电位测定的组合，证明 7-表姜烯及其脱氢衍生物 R-莪术烯作为半化学物质对烟粉虱成虫具有活性，而生姜中的立体异构体则没有。此外，R-莪术烯引起的触角电位反应最强。生物测定表明，通过添加番茄立体异构体 7-表姜烯或其衍生物 R-莪术烯，可以降低栽培番茄对烟粉虱的吸引力，使其不如邻近的番茄品种对烟粉虱有吸引力。这些倍半萜类化合物显然在烟粉虱降落前就排斥成虫，推测是因为它们告诉成虫，在降落之后，它们或它们的后代可能会接触到更高、更致命浓度的相同化合物。
