title: Allantoin has a limited role as nitrogen source in cultured coffee cells.
abstract: In plants the ureides allantoin (ALN) and allantoic acid (ALA) are formed in purine metabolism, and in some legumes both compounds play an important role as nitrogen (N) sources. In coffee plants, ALN and ALA are catabolites of caffeine degradation. Caffeine is found throughout the coffee plant and in some parts this alkaloid can accumulate up to 4% dry basis. Therefore, caffeine degradation via ureides may make an important contribution to N metabolism of the plant. Using coffee cell suspension as a model we investigated the contribution of ALN as a source of N in coffee. ALN was incorporated in the liquid medium and after 20 d of cultivation, cell mass, NO(3), NH(4), amino acids, soluble proteins, ALN and caffeine were determined in the cells. The activity of glutamine synthetase was also studied. The results showed that despite being taken up by cells ALN does not contribute significantly as a source of N in coffee cells. Compared with mineral N sources, cells grown with ALN-N accumulated much less mass. The inclusion of ALN in the medium caused significant alterations in the content of some N compounds indicating a stress condition.
authors.affiliation: Departamento de Fisiologia Vegetal, Instituto de Biologia, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brasil.
authors.forename: Sílvia B
authors.initials: SB
authors.lastname: Filippi
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Azevedo
authors.forename: Ladaslav
authors.initials: L
authors.lastname: Sodek
authors.forename: Paulo
authors.initials: P
authors.lastname: Mazzafera
mesh_terms: D000481:Allantoin / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism; D002110:Caffeine / Q000378:metabolism; D002478:Cells, Cultured; D040503:Coffea / Q000166:cytology* / Q000378:metabolism; D003470:Culture Media; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism
chemical_list: D000596:Amino Acids; D003470:Culture Media; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D000481:Allantoin; D002110:Caffeine; D009584:Nitrogen