Ethylene emission

Ultimately, fonnation of parts per million (ppm) levels of ethylene was corroborated by very carefully controlled laboratory experiments that duplicated plant timehnes and reahstic temperature swings. Eventually, the analytical data were utilized to justify the connection of a thermal oxidizer to deal with the ethylene emissions. Needless to say, if this issue had not been resolved successfully, the plant in Connecticut would have found it difficult to continue manufacturing this compound. 

LPAS has been shown to be a reliable method for the detection of ethylene in several plant physiological processes at parts per trillion concentration levels. Figure 30.11 displays the evolution of ethylene emission from a cherry tomato under different conditions (see deVries et al. (1995)). The experiment starts under anaerobic conditions the normoxic conditions are restored at I = 5.6h, yielding a sudden and huge increment of the ethylene emission for about 45 min. 

Figure 30.11 Ethylene emission from a cherry tomato under different anaerobic conditions as measured by the LPAS technique. The rapidity of the plant response and the ability of the technique to follow it can be noticed. Adapted from Harren and Reuss, in Encydopedia of Applied Physics, vol. 19, 1997, with permission of John Wiley Sons Ltd...

Figure 30.17 Top ethylene emission from non-infected grapes (o) compared with the trons-resveratrol-treated grapes ( ), for a concentration of 1.6 x 10 m trans-resveratrol in water. Bottom mock-infected (a) compared with mock-infected but previously treated with trans-resveratrol (a). Adapted from Montero et al. Plant Physiology, 2003, 131 129, with permission of the American Society of Plant Biologists...

Non-Intrusive Fruit and Plant Analysis by Laser Photothermal Measurements of Ethylene Emission... 

Ethylene Emission Pathways for Intact Cherry Tomatoes... 

Ethylene Emission Rates for Various Species 3.3.1 Local Ethylene Emission by Bell Pepper... 

Fig. 7. Photoacoustically determined ethylene emission rates, employing the two-compartment cuvette, are presented for skin (below) and calyx (above) of a red bell pepper...

Fig. 8. Fast changes between anoxic and aerobic conditions show fast changes in ethylene emission rates (PA). The measurements start with an aerobic period of 7.2 min whereafter an orange-red cherry tomato is exposed altematingly to nitrogen or air, for 1 min. In addition to the very fast ethylene response, a slow decay is observed yielding an average ethylene emission...

The last example deals with submerged Rumex species. A hypoxic atmosphere thus exists in the tissue because gas diffusion is limited in water. In contrast to Rumex acetosuy Rumex palustris shows stimulated shoot elongation in response to submergence paralleled and triggered by drastic enhancement of ethylene concentration. This elongation response is functionally related to the opportunity to reach better illuminated and aerated zones close to the water surface or preferentially above it (Voesenek and van der Veen 1994). Desubmergence of the species displays a first peak in ethylene emission with a subsequent second rise followed by a slow decay (Fig. 10). As discussed by Voesenek et al. (1993), the first peak is due to release of entrapped ethylene. The second rise corresponds to a temporary... 

Fig. 10. Ethylene emission rates from shoots of Rumex palustris before, during and after a submergence period indicated by the shaded bar. Control plants under non-submerged conditions show a constant rate...

Wolfenden, J., Robinson, D.C., Cape, J.N., Paterson, I.S., Francis, B.J., Mehlhom, H. and Wellbum, A.R (1988). Use of caretenoid ratios, ethylene emissions and buffer capacities for the early diagnosis of forest decline. New Phytologist, 109, 85-95. 

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