DNA synthesis as related to the reappearance of“light interruption rhythm”in a long-day duckweed,Lemna gibbaG3

摘要

DNA synthesis in the light perturbation period and its relation to the reappearance, due to light perturbation, of once faded-out“light interruption rhythm”in a long-day duckweed,Lemna gibbaG 3, were studied. After long continuous darkness, the duckweed incorporated3H-thymidine into both nuclear and satellite DNAsunder a light condition, but into satellite DNA alone under a dark condition. The number of dividing cells in frond epidermis increased in proportion to the length of the light perturbation period. This increase was inhibited by 5-fluorodeoxyuridine. From these and previous results we conclude that nuclear DNA newly synthesized in the light is intimately related with the reappearance of the rhy