... and glutamine; the amino acids, glutamate,aspartate, arginine and proline; and theureides, allantoin, allantoic acid and citrul-line, are common and major transportcompounds ... proteins. These pro-teins are rich in arginine and other basicamino acids (Kang and Titus, 1980), accu-mulate in the fall, disappear in the spring and are glycoproteins ... variability in NH4 and N03 availa-bility, the importance of maintaining an internal supply of N for growth and theimportance of minimizing carbon costs of assimilation (Schulze,...