Perl, M., Department of Plant Genetics, ARO, The Volcani Center, Bet Dagan, 50250, Israel
Swartzberg, D., Department of Plant Genetics, ARO, The Volcani Center, Bet Dagan, 50250, Israel
Izhar, S., Department of Plant Genetics, ARO, The Volcani Center, Bet Dagan, 50250, Israel

Two pairs of isonuclear lines of cytoplasmic male-sterile (CMS) and fertile (F) petunia cells grown in suspension culture in the presence or absence of amino acid sources were examined for uptake of 11 amino acids and adenosine. Cells from CMS lines exhibited a significant lower rate of uptake than F cells. These differences, for various amino acids, are a result of lower affinity (high Km) values and of lower maximal velocities. Although the uptake of most of the amino acids examined was affected by the availability of energy in the cell, the differences in uptake seem to be less dependent on the energy status of the cell. © 1992 Springer-Verlag.