Fig. 5

Validation of the electrochemical ethylene measurements by GC-MS. a OTR of parsley cell suspensions treated with 100 μM salicylic acid (SA) at 72 h (1) and 100 pM Pep13 at 96 h (2) (red curve) and of cells without treatment (black and grey curve). b Calculation of the ethylene partial pressure as measured with the electrochemical ethylene sensors using RAMOS and a GC-MS device. Measured ETRs were shifted to 0 μmol/L/h at 70 h, as demonstrated for Fig. 4b, before converting to corresponding ethylene partial pressures. The red curves show the average of six independent measurements. Reddish shadows indicate the standard deviation for measurements in six independent shake flasks (n = 6). Samples for GC-MS measurements were taken from two independent shake flasks after treatment with 100 μM SA at 72 h (1) and 100 pM Pep13 at 96 h (2) (red squares and red circles), and from one shake flask with untreated cell suspension (black triangels). Cultivation conditions: 250 mL RAMOS shake flask, 50 mL modified Gamborg’s B5 medium, 180 rpm shaking frequency, 50 mm shaking diameter and 25 °C