Light-dependent production of ethylene in Tillandsia usneoides L.

Tillandsia usneoides L. is a favorite model plant for investigating ethylene biosynthesis because no soil is needed for cultivation (important for long-term measurements) and small plants and different clones are available. We investigated the endogenous production of ethylene in relation to temperature, light, daylength and CO2 concentration. Using a novel and most sensitive technique to measure ethylene, laser-driven photoacoustic spectroscopy, real-time online measurements were performed. Since T. usneoides is a crassulacean acid metabolism (CAM) plant and does not take up CO2 during the day we could show that ethylene production is strictly light dependent and does not follow any endogenous rhythm. In contrast to reports on other plants, CO2 concentration did not influence the production of ethylene by T. usneoides. However, high ethylene production was obtained after application of 1-amino-acyclopropane-1-carboxylic acid (ACC).