Ethylene Measurement

The top 10 internodes of the main stems were detached, and the flower clusters and siliques were removed. For each set of measurements, 15 stems (per genotype) were placed in a 22-mL gas chromatography vial containing 0.5 mL of 0.5× liquid MS media. The vials were capped and then placed in a 16-h/8-h light/dark cycle incubator at 22°C for 5 h. The accumulated ethylene was measured and calculated based on comparison to a 1 mL/L ethylene standard (Woeste et al., 1999). Data were from three replicates, and each experiment was repeated at least once with comparable results.