11-01
P.M. Bleeker, P.J. Diergaarde,
K. Ament, S. Schütz, B. Johne, J. Dijkink, H. Hiemstra, R. de Gelder, M.T.J. de Both, M.W. Sabelis, M.A. Haring, R.C. Schuurink,
Tomato-produced 7-epizingiberene and R-curcumene
act as repellents to whiteflies,
Phytochemistry 72
(2011) 68-73
Abstract
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. (C) 2010 Elsevier Ltd.
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