Non-morphogenic metabolism during shoot induction in radiata pine cotyledon explants

The effects of excision, light and cytokinin ($N^6-benzyladenine$) on $^{14}C-acetate$ metabolism in cotyledons of Pinus radiata (D. Don) were determined. 14CO2 was released and the distribution of radioactivity into lipids, sugars, organic acids and amino acids was determined. While light and cytokinin generally caused some increase in metabolism, the effect of excision, i.e., wounding, was most pronounced. Specific metabolites examined (citrate, malate, succinate, alanine, aspartate, glutamate and glutamine) were at least 50% greater in $^{14}C-labeling$ in excised cotyledons as compared to intact seedlings. This enhancement of wound metabolism would mask possible morphogenically-related changes occurring at that time.