Selection to attract pollinators and to confuse antagonists specializes fig–pollinator chemical communications

Abstract

Chemical communication is critical in establishing angiosperm-pollinator mutualisms. However, our understanding of how chemical communication shapes coevolution remains limited. Here, we integrated information theory to model three coevolutionary scenarios (I-III), where the pollinator fitness is always optimized by the highest certainty of chemical information provided by plants, but plant fitness is determined by (I) the certainty of chemical information attracting pollinators, (II) the uncertainty of chemical information confusing antagonists, or (III) both aspects. We found that the statistical properties of empirical plant volatiles from 45 pairs of fig-pollinator mutualisms were best explained by the selection from both pollinators and antagonists (scenario III). Under this scenario, plant-pollinator mutualisms evolve to be specialized and as few as two volatile chemicals could supply sufficient information for pollinators' host identification. Our study provides new insights into plant-pollinator coevolution and will facilitate further studies on the evolution and diversification in specialized plant-pollinator-herbivore systems.

Plant scent and plant–insect interactions—Review and outlook from a macroevolutionary perspective

“…On the other hand, the field of chemical ecology has emerged as one of the extremely flourishing research fields in contemporary science, especially with the rapid development of chemical instrumentation and techniques for detection, collection, and analysis. This makes it possible to expand VOC collections from a few interacting species (e.g., one plant and one herbivore) to a relatively large scale, such as community‐level samplings (e.g., Kantsa et al, 2017; Zu et al, 2020), and—combined with information theoretical approaches—to generate new testable hypotheses (Zu et al, 2020; Yang et al, 2022; Zu et al, 2022). Such a scale provides adequate empirical data for exploring phylogenetic tools.…”

Chemical communication between plants and insects

“…In this special issue of the Journal of Systematics and Evolution , we present a collection of 10 papers addressing these challenges through original research and comprehensive reviews of relevant subfields. The contributions can be organized into four primary themes: (i) community‐level communication theory (Zu et al, 2022) and its application to plant–pollinator communities (Yang et al, 2022); (ii) the evolutionary history of communication from a phylogenetic and macroevolutionary perspective (Martel et al, 2021; Schwery et al, 2022); (iii) various communication types, including plant–pollinator (Martel et al, 2021), plant–pest (Fang et al, 2023), and plant–fungi–insect interactions (Xu et al, 2023); and (iv) an exploration of different communication factors such as distyly (Zeng et al, 2022), odor dynamics (Feng et al, 2022), chemical structures (Zhang et al, 2022), and the impact of herbicides (Ramos et al, 2022).…”

“…Plants, however, must balance minimizing uncertainty for their mutualistic pollinators while preventing antagonistic parties from eavesdropping on the information. Yang et al (2022) examined this scenario in a fig-fig wasp network system, finding that the empirical communication structures were accurately represented only when considering plants' dual objectives of attracting mutualists and confusing antagonists. This integration of information theory into plant-insect communication research holds great potential for advancing our understanding of community-level network coevolution (Sole, 2020).…”