Where, When, and Why Do Plant Volatiles Mediate Ecological Signaling? The Answer Is Blowing in the Wind

• Published in: Annual review of plant biology Vol. 74; no. 1; pp. 609 - 633
• Main Author: Schuman, Meredith C
• Format: Journal Article
• Language: English
• Published: United States Annual Reviews 22-05-2023; Annual Reviews, Inc
• Subjects: Allelochemicals; ecological signaling; Ecology; environmental chemistry and physics; Environmental conditions; Headspace; Literature reviews; Metabolic pathways; Ozone - metabolism; plant interactions; plant volatiles; Plants - metabolism; research gaps; Signal Transduction; spatial distributions; temporal dynamics; Ultraviolet radiation; Vapor pressure; Visual signals; Volatile compounds; Volatiles; Wind; plant volatiles; environmental chemistry and physics; ecological signaling; spatial distributions; plant interactions; research gaps; temporal dynamics
• ISSN: 1543-5008; 1545-2123
• DOI: 10.1146/annurev-arplant-040121-114908

Plant volatiles comprise thousands of molecules from multiple metabolic pathways, distinguished by sufficient vapor pressure to evaporate into the headspace under normal environmental conditions. Many are implicated as ecological signals, but what is the evidence-and how do they work? Volatiles diffuse, are carried by wind, and may be taken up by other organisms or degrade with exposure to atmospheric ozone, radicals, and UV light; visual signals such as color are not subject to these complications (but require a line of sight). Distantly related plants-and nonplants-produce many of the same volatiles, yet specific compounds and blends may be distinct. Here, I present a quantitative review of the literature on plant volatiles as ecological signals, illustrating a field that has focused on developing ideas as much as reporting primary data. I discuss advantages and constraints, review recent advances, and propose considerations for primary studies to elucidate particular functions of plant volatiles.