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Amino Acid Transport in Suspension-Cultured Plant Cells

1982; Oxford University Press; Volume: 69; Issue: 1 Linguagem: Inglês

10.1104/pp.69.1.246

1532-2548

Carl N. McDaniel, Robert K. Holterman, Roger Bone, Paul M. Wozniak,

Polyamine Metabolism and Applications

The transport of l-arginine (l-Arg), l-aspartic acid (l-Asp), l-histidine (l-His), and l-phenylalanine (l-Phe) has been investigated in suspension cultures of Nicotiana tabacum cv. Wisconsin 38 cells. Uptake of these amino acids is pH- and energy-dependent, concentrative (except for l-Asp), stereospecific, dependent upon culture growth phase, and, apparently, carrier-mediated. A 1,000-fold higher concentration of l-leucine (l-Leu) can inhibit all of the energy-dependent uptake of l-Arg, l-Asp, l-His, and l-Phe. A 1,000-fold higher concentration of l-Arg or l-Phe can inhibit all of the energy-dependent uptake of l-Leu. l-Asp and l-His cannot inhibit all of the energy-dependent l-Leu uptake. However, evidence is presented which indicates that l-Leu enters the cell via the carrier system which also transports l-Asp and l-His. These inhibition data are consistent with the hypothesis that all of these amino acids are transported by a single carrier system.