Germination of lettuce induced by inhibitors of protein synthesis.

L-threo chloramphenicol and actinomycin D act like D-chloramphenicol in being able to promote germination of light-requiring seeds of Lactuca sativa in darkness. The two isomers of chloramphenicol at relatively low concentrations also prevent the development of skotodormancy. Protein synthesis, measured by the incorporation of tritiated leucine, occurs in dormant seeds in darkness; evidence suggests that this occurs most intensively in the endosperm. The stimulation of germination by chloramphenicol and actinomycin D is preceded by a marked reduction in protein synthesis. It is suggested that these substances act by arresting an inhibitory process which requires protein synthesis.