© 1989 Heron Publishing—Victoria, Canada
Growth and soluble proteins of cell cultures derived from explants and protoplasts of Pinus pinaster cotyledons
H. David, C. Laigneau and A. David
Laboratoire de Biologie et Physiologie Végétales, Université de Bordeaux I, Allée des Facultés, 33405
Talence Cedex, France / Received January 13, 1989
Summary
Pinus pinaster Ait. cell suspension cultures were derived from chopped cotyledons and from cotyledon protoplasts. When transferred after
12 weeks in culture, growth of both cell types showed a lag of 5 days followed by an exponential phase of 14 days for the
protoplast-derived cells and 23 days for the
organ-derived cells. During the exponential growth phase, packed cell volume of protoplast-derived cultures increased 7-fold
and that of organ-derived cultures 13-fold. During the stationary phase, the diameters of protoplast-derived cells averaged
80 μm and those of organ-derived cells 100 μm. After 30 days, the media containing protoplast-derived and organ-derived cells
decreased in osmolarity by 50 and 120 mOs per kg water, respectively, and in pH by 1.4 and 2.0 units, respectively. Throughout
the growth cycle, protein content per unit of packed cell volume was always at least 35% higher in the protoplast-derived
cultures than in the organ-derived cultures. Two-dimensional electrophoretic separation of soluble proteins revealed three
peptides present in protoplast-derived cells that were absent from organ-derived cells and two peptides present in organ-derived
cells that were absent from protoplast-derived cells. Other peptides differed quantitatively between the cell types.
