Effects of X irradiation on corn seed.

There is no biochemical explanation for the inhibition of germination and seedling growth after X irradiation of seeds (1). Although some enzyme activities are altered (9, 10, 13) by X irradiation, enzyme inactivation does not seem to be the primary biochemical mechanism of radiation injury (20). Little attention has been given to physiological and biochemical aspects of growth of seedlings from X-irradiated seed. Experiments reported here represent studies on the effect of X irradiation on germination of cornseed and subsequent growth. The effect of seed X irradiation on the subsequent metabolism of protein, nucleotides, ribonucleic acid (RNA)4, and reducing sugar of corn seedlings was determined. The activity of mitochondria and glycolytic enzymes, and respiration of excised tissue was measured.