Enhanced development and differentiation of protoplasts and spores of green and red seaweeds by a Pterocladia agar from New Zealand

Enhanced growth of macroalgae was observed on High Purity Agar, a product of Coast Biologicals Limited of Auckland New Zealand. Increases in rates of cell divisions and tissue differentiation occurred in green and red seaweeds. Protoplasts, spores, and vegetative thalli were all affected. The enhancement of growth and differentiation was concentration dependent, with high concentrations (> 1 %) appearing toxic. Few cells survived on 1 % and 1.5 % agar; over 8 weeks of culture these developed into plantlets six fold larger than those grown on an 0.3 % gel of the same agar, and as much as 11 fold larger than control plants grown on Difco Bacto agar at the same gel concentration. The activity was heat stable, water soluble, and largely bound to the carbohydrate matrix. The chemical nature of the active compound is under investigation.     

The role of the cell-apex in elongation ofAcetabularia

Summary Exposure of only the apical portion of anAcetabularia cell to light causes the cell to elongate as much as cells which are totally illuminated. No elongation takes place if only the apical portion of the cell is kept in the dark.In totally illuminated cells, preferential exposure to DCMU of the apical region only also inhibits cell elongation.Local-photosynthesis in the apical region might be essential for elongation. The participation of other photomorphogenetic reactions in the apical region are not excluded.