Floral scent in a whole‐plant context: moving beyond pollinator attraction

Abstract

The natural world is awash with odours – blends of volatile organic compounds (VOCs) – whose chemical structures and composition convey information to organisms endowed with the sensory capacity to perceive them. Pheromones and other chemical signals provide specific information that facilitates kin recognition, mate acquisition, social interactions and defence across the tree of life (Meinwald & Eisner 2008). Even more general volatile cues, such as CO2, convey context-dependent information about habitat and host or food quality, illness and microbial decay (Guerenstein & Hildebrand 2007). The terrestrial fossil record teems with evidence of chemical communication and warfare, in the form of animal olfactory appendages (Strausfeld & Hildebrand 1999; Labandeira 2002) and plant essential oil glands (Fahn 2002; Krings, Taylor & Kellogg 2002). This evidence, combined with our knowledge of cycads, water lilies and other ‘living fossils’ (Thien, Azuma & Kawano 2000; Terry et al. 2007), attests to the antiquity of volatile communication between plants, their mutualists and antagonists.