Ontogenetic and spatio-temporal patterns of induced volatiles in <Emphasis Type="Italic">Glycine max</Emphasis> in the light of the optimal defence hypothesis |
| |
Authors: | Michael Rostás Katharina Eggert |
| |
Institution: | (1) Julius-von-Sachs Institute for Biosciences, Department of Botany II, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany |
| |
Abstract: | Summary. Plants attacked by herbivorous insects emit a blend of volatile compounds that serve as important host location cues for parasitoid
wasps. Variability in the released blend may exist on the whole-plant and withinplant level and can affect the foraging efficiency
of parasitoids. We comprehensively assessed the kinetics of herbivore-induced volatiles in soybean in the context of growth
stage, plant organ, leaf age, and direction of signal transport. The observed patterns were used to test the predictions of
the optimal defence hypothesis (OD). We found that plants in the vegetative stage emitted 10-fold more volatiles per biomass
than reproductive plants and young leaves emitted >2.6 times more volatiles than old leaves. Systemic induction in single
leaves was stronger and faster by one day in acropetal than in basipetal direction while no systemic induction was found in
pods. Herbivore-damaged leaves had a 200-fold higher release rate than pods. To some extent these findings support the OD:
i) indirect defence levels were increased in response to herbivory and ii) young leaves, which are more valuable, emitted
more volatiles. However, the fact that reproductive structures emitted no constitutive or very few inducible volatiles is
in seeming contrast to the OD predictions. We argue that in case of volatile emission the OD can only partially explain the
patterns of defence allocation due to the peculiarity that volatiles act as signals not as toxins or repellents. |
| |
Keywords: | Indirect plant defence soybean Spodoptera frugiperda tritrophic interactions variability |
本文献已被 SpringerLink 等数据库收录! |
|