Fig. 6

Barley variety dependent VOC emissions upon mock or BTH treatment Exemplary VOC emission rates of three different barley varieties (from left to right: Morex, Barke, Golden Promise) upon treatment with the elicitor BTH (black line) or mock treatment (red line). Distinct VOC emission patterns allow to differentiate the different genotypes. Methanol is a typical growth marker and was thus emitted by all plants. Hexenal is a typical stress marker and correlated with an apparent plant degradation towards the end of the experiment (no emission by Morex plants). BTH treatment induced the emission of methanethiol, an ion with sum formula \(\hbox{C}_{7}\hbox{H}_{10}\hbox{O}\)–\(\hbox{H}^+\) and monoterpenes. (data are means of 8 biological replicates for each variety in the BTH treatment and of 6 biological replicates in the mock treatment; for compounds, where no PTR-ToF-MS sensitivity was available, the signals were only normalized to the plant leaf area)