Anthocyanin Impacts Multiple Plant-Insect Interactions in a Carnivorous Plant

Area of Science:

• Ecology
• Evolutionary Biology
• Plant Science

Background:

• Plant coloration is hypothesized to serve multiple ecological functions, but these are often studied in isolation.
• Ecological pleiotropy, where a single trait influences multiple ecological interactions, may maintain color variation within species.
• Anthocyanins, red plant pigments, are key to understanding plant-insect interactions and coloration.

Purpose of the Study:

• To investigate the adaptive value of red plant pigment (anthocyanin) in the carnivorous pitcher plant (Sarracenia purpurea).
• To examine how anthocyanins mediate multiple plant-insect interactions, including prey capture, herbivore damage, and larval recruitment.
• To test the hypothesis of ecological pleiotropy maintaining color polymorphism in Sarracenia purpurea.

Main Methods:

• Comparison of red and green color morphs of Sarracenia purpurea in natural sympatric populations.
• Integration of field and laboratory bioassays, visual modeling, and chemical analysis of anthocyanins.
• Long-term demographic study to assess recruitment and reproductive success.

Main Results:

• Each color morph exhibited differential performance in various ecological contexts, indicating opposing selection pressures.
• Evidence suggests anthocyanins mediate multiple plant-insect interactions, with both benefits and costs associated with their production.
• Stable color polymorphism and seed set data support the role of balancing selection in maintaining variation.

Conclusions:

• Ecological pleiotropy, driven by anthocyanin production, plays a significant role in maintaining intraspecific diversity in plant color.
• Opposing ecological interactions exert selection on plant color, leading to the maintenance of variation.
• This study demonstrates how a single pigment can influence multiple key plant-insect interactions, shaping plant evolution.