4.7 Ethylene measurement
Ethylene production was measured as previously described (Leibman-Markus et al., 2017). Leaf discs 0.9 cm in diameter were harvested from indicated genotypes, and average weight was measured for each plant. Discs were washed in water for 1-2 h. Every six discs were sealed in a 10 mL flask containing 1 ml assay medium (with or without 1 μg ml-1 EIX) for 4h at room temperature. Ethylene production was measured by gas chromatography (Varian 3350, Varian, California, USA).