Spatial distribution of ethylene production by individual needles along a shoot of Pinus sylvestris L. Relationship with peroxidase activity

Spatial distribution of ethylene production by individual current year needles and the relationship with peroxidase activity was studied along a shoot of Scots pine (Pinus sylvestris L.). Much variation in ethylene production between and within individual seedlings was found. There was a significant difference in mean intensity of ethylene production between orthostichies within individual seedlings. The capacity of individual needles to convert 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene did not correlate with the basal rate of ethylene production. Mean ethylene production intensity by orthostichies correlated positively with mean peroxidase activity. A positive correlation between the intensity of ethylene production by individual needles and detachment-induced peroxidase activity was found. The data suggests that the rate of ethylene production by individual needles may be directly related to their peroxidase activity and at least in part to their antioxidative capacity.