Abstract Detail

Ecology

McCoy, Rachel [1], Widhalm, Joshua [2], McNickle, Gordon [3].

Allelopathy as an evolutionarily stable strategy.

Plants compete for the finite resources available in an area with surrounding organisms. Plants can increase their competitive ability through allelopathy, which is the release of a toxic chemical into the environment by a plant to inhibit the growth and development of competing organisms. Some plants use specialized metabolites for allelopathy, often in a lineage-specific manner. Such plant allelochemicals are promising candidates for new herbicides with novel modes of action and have been implicated in the invasion success of some invasive species, like garlic mustard (Alliaria petiolata). Despite the importance of allelochemicals, the circumstances and conditions that favor the development and maintenance of allelochemicals is not well understood. In order to gain insight into the cost and benefit of allelopathy, we have developed a 2-by-2 matrix game to model the interaction between plants that produce allelochemicals and plants that do not. Production of an allelochemical introduces a novel cost to a plant, both in terms of synthesis and in detoxifying a toxic chemical, but may also convey a competitive advantage. A plant that does not produce an allelochemical will suffer the cost of encountering one. Our model predicts three cases, differing in the benefit to the allelopathic plant, in which the evolutionarily stable strategies are different. In the first, the non-allelopathic plant is a stronger competitor, and not producing allelochemicals is the evolutionarily stable strategy. In the second, the allelopathic plant is the better competitor and production of allelochemicals is the more beneficial strategy. In the last case, the allelopathic and non-allelopathic plants are equal competitors, but pay different costs. The allelopathic plant pays the cost of making, deploying, and detoxifying the chemical, while the non-allelopathic plant pays the cost of encountering the allelochemical. The evolutionarily stable strategy in this case, which likely represents populations in which allelopathic and non-allelopathic plants coexist, depends on the relative magnitude of the cost to the allelopathic and non-allelopathic plants. Our model sheds light on the circumstances leading to the evolution of allelochemicals. One potential application of this model is in the engineering of crops that produce allelochemicals for weed control. In this case, the cost of production and detoxification of the allelochemical should remain low enough that the crop is able to grow while suppressing weed species.

1 - Purdue University, Horticulture and Landscape Architecture, 625 Agriculture Mall Dr, West Lafayette, Indiana, 47907, United States
2 - Purdue University, Horticulture And Landscape Architecture, 625 Agricultural Mall Drive, West Lafayette, IN, 47907, United States
3 - Purdue University, Botany and Plant Pathology, 915 W State Street, West Lafayette, Indiana, 47907, United States

Keywords:
Allelopathy
ecology
game theory.

Presentation Type: Poster
Session: P, Ecology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC031
Abstract ID:1002
Candidate for Awards:Ecological Section Best Graduate Student Poster