Ethylene, light-induced formation

Figure 4. A Light-induced formation of ethane and ethylene over 60 min with isolated spinach chloroplasts in the presence of 1 fxM oxyfluorfen and 1 fxM oxyfluorfen combined with 1 /mM DCMU (diuron). B Decrease of the Hill reaction (oxygen evolution system H2O potassium ferricyanide) during incubation of isolated chloroplasts in the light with 1 /mM oxyfluorfen present (12, 31),...

The peroxidative reactions were mediated and sustained by Cu(II) ions in the light. Table IV shows that fatty acids with at least 2 double bonds are necessary for hydrocarbon formation. As Anacystis lacks those fatty acids, no peroxidative volatile hydrocarbons were produced. Spirulina exclusively contains CO-6 fatty acids as endogenous polyunsaturated fatty acids and evolved Cs hydrocarbons only. The third species, Anabaena, whose thylakoids contain co-3 and Co-6 polyunsaturated fatty acids formed C2 and C5 hydrocarbons simultaneously. We conclude that co-3 polyunsaturated fatty acids are the source of ethane and ethylene and that the CO-6 polyunsaturated fatty acids are the source of pentane and pentene in herbicide-induced peroxidation reactions. Furthermore, we obtained evidence that the propane measured with Bumilleriopsis after an 18-h treatment with either 10 >iM oxyfluorfen or 50 jxM Cu(II) originates from a CO-4 polyunsaturated fatty acid. We have recently isolated and identified this acid as 16 3CO4 (Sandmann, Lambert, B5ger in preparation). 

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