Herbivory and floral signaling: phenotypic plasticity and tradeoffs between reproduction and indirect defense

Citations Over TimeTop 1% of 2014 papers

Abstract

Plant defense against herbivores may compromise attraction of mutualists, yet information remains limited about the mechanisms underlying such signaling tradeoffs. Here, we investigated the effects of foliar herbivory by two herbivore species on defense compounds, floral signaling, pollinator and parasitoid attraction, and seed production. Herbivory generally reduced the quantity of many floral volatile organic compounds VOCs) in Brassica rapa. By contrast, floral color, flower diameter, and plant height remained unaffected. The decreased amounts of floral volatiles led to reduced attractiveness of flowers to pollinators, but increased the attractiveness of herbivore-infested plants to parasitoids. Plants infested with the native butterfly Pieris brassicae produced more flowers during early flowering, effectively compensating for the lower olfactory attractiveness. Herbivory by the invasive Spodoptera littoralis increased the amounts of glucobrassicanapin, and led to delayed flowering. These plants tended to attract fewer pollinators and to produce fewer seeds. Our study indicates a tradeoff between pollinator attraction and indirect defense (parasitoid attraction), which can be mitigated by reduced floral VOC emission and production of more early flowers. We suggest that this compensatory mechanism is specific to plant-herbivore associations with a coevolutionary history.

Related Papers

• → Land use and pollinator dependency drives global patterns of pollen limitation in the Anthropocene(2020)167 cited
• → ECOLOGICAL COSTS OF PLANT RESISTANCE TO HERBIVORES IN THE CURRENCY OF POLLINATION(1999)124 cited
• → Pollen tube growth from multiple pollinator visits more accurately quantifies pollinator performance and plant reproduction(2020)33 cited
• → Pollinator dependence but no pollen limitation for eight plants occurring north of the Arctic Circle(2020)22 cited
• → Pollinator limitation on reproductive success in Iris tuberosa(2014)20 cited