DEPENDENCE ON ENERGY AND AEROBIC METABOLISM OF INITIATION OF DNA SYNTHESIS AND MITOSIS BY G1 AND G2 CELLS

Following establishment by carbohydrate starvation of a stationary phase in pea root tip meristems, the requirements for initiation of cell proliferation were investigated. Entry of G1 cells into S (DNA synthesis), G2 cells into M (mitosis) and progression of G1 cells through S and G2 into mitosis were prevented by carbohydrate starvation, anaerobiosis or treatment with 2,4-dinitrophenol. The data show that (a) both DNA synthesis and mitosis require aerobic conditions and are energy-dependent and (b) events prior to the initiation of these processes have relatively greater energy requirements than the rest of the mitotic cycle. © 1969.