Amino acid pools in Cyanidium caldarium (Tilden) Geitler, growing under conditions of sufficiency of nutrients (sufficient cells), or under conditions of nitrogen, potassium or phosphorus limitation (N-, K- or P-limited cells), and responses upon nutrient resupply were investigated. Glutamate was the dominant amino acid in sufficient cells [11.2-mu-mol ml-1 packed cell volume (pcv)], in N-limited cells (7.71-mu-mol ml-1 pcv) and in P-limited cells (7.46-mu-mol ml-1 pcv), whereas in K-limited cells the dominant amino acid was alanine (8.83-mu-mol ml-1 pcv). Other amino acids detected occurring at significantly high concentrations were: citrulline, alanine, aspartate, glutamine and delta-aminolevulinic acid in sufficient cells, alanine in N-limited cells; alanine, citrulline, serine, arginine and asparagine in P-limited cells; glutamate, arginine, glutamine, citrulline, asparagine, serine, aspartate and putrescine in K-limited cells. On adding NH4+ to N-limited cells the level of glutamate decreased and then increased to the starting value; there occurred an increase in the level of glutamine, aspartate, citrulline, arginine, alanine, serine, as well as of delta-ALA and putrescine. Resupply of Pi to P-limited cells caused a significant decrease of glutamate and a concomitant increase of alanine, but was without effect on the concentration of other amino acids. On adding K+ to K-limited cells there was an increase of glutamate and citrulline, and a decrease of putrescine, whereas arginine and alanine remained unvaried at the very high level occurring before addition.

Amino-acid Pools In Nutrient Limited Cyanidium-caldarium and Responses To Resupply

V. VONA;ESPOSITO, SERGIO;
1992

Abstract

Amino acid pools in Cyanidium caldarium (Tilden) Geitler, growing under conditions of sufficiency of nutrients (sufficient cells), or under conditions of nitrogen, potassium or phosphorus limitation (N-, K- or P-limited cells), and responses upon nutrient resupply were investigated. Glutamate was the dominant amino acid in sufficient cells [11.2-mu-mol ml-1 packed cell volume (pcv)], in N-limited cells (7.71-mu-mol ml-1 pcv) and in P-limited cells (7.46-mu-mol ml-1 pcv), whereas in K-limited cells the dominant amino acid was alanine (8.83-mu-mol ml-1 pcv). Other amino acids detected occurring at significantly high concentrations were: citrulline, alanine, aspartate, glutamine and delta-aminolevulinic acid in sufficient cells, alanine in N-limited cells; alanine, citrulline, serine, arginine and asparagine in P-limited cells; glutamate, arginine, glutamine, citrulline, asparagine, serine, aspartate and putrescine in K-limited cells. On adding NH4+ to N-limited cells the level of glutamate decreased and then increased to the starting value; there occurred an increase in the level of glutamine, aspartate, citrulline, arginine, alanine, serine, as well as of delta-ALA and putrescine. Resupply of Pi to P-limited cells caused a significant decrease of glutamate and a concomitant increase of alanine, but was without effect on the concentration of other amino acids. On adding K+ to K-limited cells there was an increase of glutamate and citrulline, and a decrease of putrescine, whereas arginine and alanine remained unvaried at the very high level occurring before addition.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/472213
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