Effect of kinetin on the course of cell cycle in successive developmental stages of the antheridial filaments of Chara vulgaris L.

Abstract

Effects of kinetin on the course of cell cycle in successive developmental stages of the antheridial filaments of <em>Chara vulgaris</em> L. were investigated. A shortening of the duration of cell cycles has been observed, particularly in initial. and final developmental stages. S phase. shortened in all stages whereas G<sub>2</sub> phase+mitosis shortened in early but become longer in late developmental stages of filaments. Incorporation of <sup>14</sup>C-adenine into cell nuclei increased after kinetin treatment in 4- and 8-celled filaments whereas that of <sup>3</sup>H-phenylalanine increased in 8- and particularly 16-celled ones. This plant growth regulator stimulated also the <sup>3</sup>H-thymidine incorporation into cells in studied developmental stages of filaments. The stimulation of radioactive phenylalanine incorporation into nucleus and cytoplasm was stronger in late G<sub>2</sub> phase. A participation of cytokinins in the control of cell cycle in relation to process of differentiation of antheridial cells is discussed. A possibility of changes in the cytokinin content in antheridia and antheridial filament cells during their; development has been postulated.