Tropospheric Ozone Alters the Chemical Signal Emitted by an Emblematic Plant of the Mediterranean Region: The True Lavender (Lavandula angustifolia Mill.)

Among air pollutants, tropospheric ozone (O 3 ) is one of the most stressful for organisms due to its strong oxidative potential. For instance, high concentration ([O ]) has potential affect (i) emission volatile organic compounds (VOCs) by plants and (ii) lifetime these VOCs in atmosphere, consequently disturb crucial signals interactions between other organisms. However, despite determinant role emitted flowers pollinator attraction, a very limited number studies have investigated impact O on floral VOCs. In this study, we effect [O ] episodes flowering Mediterranean plant: true lavender ( Lavandula angustifolia Mill., Lamiaceae). To do so, controlled conditions, exposed entire plant but realistic (200 ppb 5 h) only increasing (0, 40, 80, 120, 200 ppb). We sampled both conditions analyzed them Gas Chromatography-Mass Spectrometry order qualify quantify lavender’s emissions reaction with atmosphere. Our results showed that exposure during short period (5 did not lavender. Incidentally, also chemical signal varied quantities proportions over day. Moreover, after their plant, composition changed quantitatively qualitatively an atmosphere containing naturally observed nowadays. Quantities several major terpenes decreased drastically exposure, whereas concentrations some increased, such as carbonyls carboxylic acids, which are probably products . Exposure thus directly affected Because pollinators generally use blend particular localize flowers, numerous may experience difficulty recognizing specific odors frequent moderate region.