Ethylene-biosynthesis in conifers: Investigations on the emission of ethylene and the content of ACC and MACC in Norway Spruce (Picea abies) and silver fir (Abies alba)

The assessment of forest damage is carried out throughout the European Community by evaluation of the loss and yellowing of leaves or needles. The results of this ocular damage diagnosis can be confirmed and stated more precisely by applying biochemical criteria, e.g. by monitoring ethylene, its precursor ACC (1-amino-cyclopropane-carboxylate) and the malonyl conjugate of ACC malonyl-amino-cyclopropane-carboxylate (MACC). Therefore we investigated ethylene emissions well as ACC and MACC contents in six Norway Spruce trees (Picea abies) each of eleven permanently monitored sites in the southwest of Germany. The same examinations were applied with silver fir at two additional sites. The results indicate that damaged trees produce more ACC, MACC and ethylene than undamaged. In addition the course of annual changes of the three parameters have been measured.