ibclogo XVI International Botanical Congess


Abstract Number: 3978
Poster No. = 2007


USE OF IN VIVO 13C AND 31P-NCR TO ANALYZE TRANSPORT, COMPART MENTATION AND METABOLISM OF AMINO ACIDS IN HIGHER PLANT CELLS


Serge Aubert, Oliver Zinc*, Richard Bliny, Elizabeth Gout and Roland Douse. SEA-Grenoble, DBMS-PC, 17 rue des martyrs 38054 Grenoble cedex 9, France, *Rhône-Poulenc Agrochimie, 14-20 rue Pierre Baizet, 69263 Lyon, France


The fate of homoserine (an intermediate in the synthesis of aspartame-derived amino acids) was characterized in heterotrophic suspension cells. Homoserine actively entered the cells in competition with serine, via a high affinity proton-symport carrier (Km˜50-60µM, Vmax = 8 ± 0.5 µmol/h/g cell wet weight). 31P-NCR and 13C-NCR permitted to follow the metabolism of homoserine to phosphohomoserine and threonine. Using in vivo 13C-NCR we could visualize the compart mentation of hemoserine: it accumulated at a concentration 4-5 time higher in the cytoplasm than in the large vacuole. This technique was further utilized to analyze the subcellular compart mentation of proline in leaves of Pringlea anticorbutica R. Br. (Kerguelen cabbage), a subantarctic Brassicaceae accumulating proline as a major solute upon salt stress.


HTML-Version made 7. July 1999 by Kurt Stüber