Health monitoring of plants by their emitted volatiles: trichome damage and cell membrane damage are detectable at greenhouse scale

Abstract

Pathogen attack and herbivore infestation have a major impact on plant health. In a model study, these two plant health issues were simulated to study whether plant health can be monitored at greenhouse scale through the analysis of volatile organic compounds (VOCs) in greenhouse atmosphere. To simulate pathogen attack and herbivore infestation, we repeatedly stroked the stems of tomato plants (Lycopersicon esculentum) and repeatedly removed their side shoots. In addition, we studied the effect of fruit picking on the concentration of plant‐emitted VOCs in greenhouse atmosphere. Analysis of air samples obtained before these treatments revealed up to 17 VOCs that are known to be released from tomato plants, of which the most dominant one was the monoterpene β‐phellandrene. When plants were 7 weeks old, the concentration of this VOC was approximately 0.06 ppbv before treatment. When plants were 12 weeks old, this concentration was raised to approximately 0.14 ppbv. Stroking of the stems, removing the side shoots and fruit picking resulted in an increase in the concentrations of all mono‐ and most sesquiterpenes up to 60‐fold, which was expected because these VOCs are well‐known constituents of trichomes. The treatments did not result in substantially increased concentrations of the stress‐related compounds α‐copaene, methyl salicylate and (E,E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene. In contrast to stroking and fruit picking, shoot removal resulted in the emission of the lipoxygenase‐derived product (Z)‐3‐hexenol in greenhouse atmosphere expressing cell membrane degradation. The findings presented in this paper focus on the feasibility of monitoring plant health through the analysis of VOCs in greenhouse air, but findings might also be relevant for atmospheric chemistry.

Workplace Concentrations and Exposure Assessment of Monoterpenes in Rosemary‐ and Lavender‐growing Greenhouses

“…Further, the airtight structure of greenhouses may be responsible for increasing monoterpene concentrations. However, with the exception of a study on a tomato-growing greenhouse 13) , no study of the effect of environmental conditions, horticultural tasks and ventilation rate on greenhouse monoterpene concentrations has been reported. To assess the atmospheric risk for greenhouse workers, it is important to obtain data on monoterpene concentrations in herbgrowing greenhouses.…”

Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

“…This is an important consideration because different VOCs, even within the same class of compounds, can vary by orders of magnitude in their chemical reactivity (Atkinson and Arey, 1998). A variety of stress exposure studies have been performed investigating BVOC emission changes due to ozone exposure (Heiden et al, 1999;Vuorinen et al, 2004), salt stress (Loreto and Delfine, 2000;Teuber et al, 2008), increased CO 2 (Calfapietra et al, 2009;Constable et al, 1999), enhanced radiation (Harley et al, 1996), drought and/or high temperatures (Kleist et al, 2012;Niinemets, 2010;Niinemets et al, 2010), herbivory (Achotegui-Castells et al, 2013;Copolovici et al, 2011;Engelberth et al, 2004), and pathogen attack (Jansen et al, 2009a;Toome et al, 2010). A thorough review on this topic was presented by Peñuelas and Staudt (2010).…”

Induced plant volatiles allow sensitive monitoring of plant health status in greenhouses

“…However, the concentrations of methyl salicylate remained stable after stroking of stems, after removal of side shoots, and after picking fruits. 24 Three reasons may account for this: (1) B. cinereaderived elicitors were absent in the above mentioned treatments. These elicitors may play an important role in the induction of methyl salicylate emission from tomato plants.…”

“…24 Almost certainly, every other crop operation will affect the emission of mono-and sesquiterpenes. Also temperature determines the emission of mono-and sesquiterpenes.…”