ABSTRACT
Plant secondary metabolites in general, and volatile organic compounds (VOCs) in particular, serve a multitude of ecological functions for plants, from protecting them from abiotic stresses, such as frost, drought, and UV radiation (Blande et al. 2014; Loreto and Fineschi 2015; Loreto et al. 2014) to mediating a large diversity of antagonistic and mutualistic biotic interactions (Dicke and Baldwin 2010; Heil and Karban 2010; Turlings and Ton
12.1 Introduction: Plant volatile organic compounds as information channels ........................................................................... 283
12.2 The limits of a chemical language ...................................................... 286 12.2.1 The ecologic niche analogy: Fundamental and realized
information space ..................................................................... 286 12.2.2 Inherent constraints in secondary metabolite production ..... 289 12.2.3 Diversity and multifunctionality of plant secondary
metabolites ................................................................................. 291 12.3 VOC-mediated information transfer in biotic interactions............. 294
12.3.1 Herbivores and pollinators interacting with plants: The mutualist-antagonist continuum ........................................... 294
12.3.2 Information-mediated indirect resistance: VOCmediated multitrophic level interactions .............................. 300
12.3.3 VOC-mediated plant-plant communication ......................... 302 12.4 Conclusion ............................................................................................. 305 Acknowledgments ......................................................................................... 306 References ........................................................................................................ 306
2006). Plant chemicals are increasingly found as carriers of information that mediate interactions with organisms in the plant’s environment. More specically, it has been hypothesized that the “least common denominator function” of plant secondary metabolites may indeed be information exchange within the plant (e.g., signal transduction between tissues and distant modules) and of the plant with its biotic environment. While this information-mediating function of plant secondary metabolites in general has been discussed elsewhere (Kessler 2015), here we will focus on VOCs, lipophilic liquids with low molecular weight and high vapor pressure at ambient temperatures (Pichersky et al. 2006).
