Pappas Maria L, Steppuhn Anke, Geuss Daniel, Topalidou Nikoleta, Zografou Aliki, Sabelis Maurice W, Broufas George D
Department of Agricultural Development, Democritus University of Thrace, Orestiada, Greece.
Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.
PLoS One. 2015 May 14;10(5):e0127251. doi: 10.1371/journal.pone.0127251. eCollection 2015.
Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur) on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI), may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood). The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators.
许多捕食食草动物的捕食性昆虫也会取食植物，但尚不清楚植物是否通过诱导防御来应对这种植食行为，从而影响食草动物的表现。我们研究了杂食性捕食者矮小广翅蜡蝉（Macrolophus pygmaeus，Rambur）预先存在于番茄植株上是否会影响植株对两种不同食草动物的抗性。除了矮小广翅蜡蝉通过植物介导对食草动物表现产生的影响外，我们还研究了一种已知可被食草动物诱导的植物防御性状——蛋白酶抑制剂（PI），是否也会因这种捕食者与番茄植株的相互作用而被激活。我们发现，将番茄植株暴露于杂食性捕食者矮小广翅蜡蝉下，会降低随后侵染的食草动物二斑叶螨（Tetranychus urticae Koch）的表现，但不会影响温室白粉虱（Trialeurodes vaporariorum，Westwood）。当先前暴露于食虫植物性捕食者时，被叶螨侵染的番茄植株上的食草动物负荷较低，即产卵数量和个体数量较少。这种影响并不局限于暴露的叶片，在捕食者移除后，在暴露的植株上至少持续两周。由于植株先前暴露于矮小广翅蜡蝉而导致叶螨表现下降，同时伴随着已知参与植物防御的蛋白酶抑制剂转录本的局部和系统积累增加以及活性增强。我们的结果表明，食虫植物性捕食者可以诱导植物防御反应并降低食草动物的表现。因此，食虫植物性捕食者诱导植物防御可能会加强通过捕食对某些食草动物种群的抑制作用。
