Feeding [1-14C]-guanidinoacetic acid to shoot primordia, O2 uptake was inhibited and major products were 14C-glycine, 14CO2 and 14C-serine. The direct decarboxylation of [1-14C]-guanidinoacetic acid to 14CO2 and N-methylguanidine, the methylation of [1-14C]-guanidinoacetic acid to 14C-creatine, and the lytic cleavage to urea and 14C-glycine were all ruled out. Enzymatic transamidinations of [1-14C]-guanidinoacetic acid with amino acid acceptors occurred as arginine-rich storage proteins were being turned over and new proteins synthesized containing 14C-glycine and 14C-serine. The products of transamidination were recycled as substrates until 14C-glycine was metabolized in different directions and transported to mitochondria and peroxisomes. 14C-Glycine was decarboxylated by a glycine decarboxylase multienzyme complex resulting in a net carbon loss and a sharp decline in total protein rich in arginine N. Under these conditions, unlabelled arginine and ornithine contributed as substrates for reversible transamidination reactions. Peroxisomes and mitochondria are hypothesized as providing arginine-derived nitric oxide to maintain redox homeostasis in response to the stresses imposed by [1-14C]-guanidinoacetic acid and to protect against the inhibitory activity of sulfhydryls on transamidinase activity. The destruction of a respiratory inhibitor by transamidination may comprise a mechanism associated with the awakening from of dormancy and the mobilization of storage protein reserves in conifers.

Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors.