Growth Behavior of a Liverwort, Jungermannia subulata Evans, in a Cell Suspension Culture. The Role of Organic Acids Required for Cell Growth

Abstract
A green callus of a liverwort, Jungermannia subulata Evans, was induced from gametophytes, and a cell suspension culture was obtained from the callus. Both callus and suspension-cultured cells grew in a modified Murashige and Skoog medium if organic acids of the TCA cycle were supplied. In the cell suspension culture of J. subulata, ammonium was taken up preferentially by the cells particularly at the earliest stage of growth, while only a negligible amount of nitrate was utilized as long as ammonium was present in the medium, and this unbalanced utilization of the two nitrogen sources caused an abrupt drop in the pH of the medium. The organic acids of the TCA cycle supported the growth of this cell line by preventing the abrupt drop in the pH of the medium.