Dormancy in Seeds of Charlock (Sinapis arvensis L.): Early Effects of Gibberellic Acid on the Synthesis of Amino Acids and Proteins.

Charlock (Sinapis arvensis L.) seeds were imbibed with 10 mm GA(3) for 24 hours at 0 C. After equilibration at 25 C, a 5-fold increase in radioactivity in the amino acids labeled from 2-(14)C-acetate was observed within 2 hours. The total amount of amino acids was reduced to half, and the specific radioactivity increased approximately 10-fold, indicating a diversion of metabolites for amino acid and protein synthesis in GA(3)-treated seeds. The rate of incorporation of l-(14) C-leucine into protein was doubled. Autoradiographs showed that enhancement of protein synthesis was localized in the shoot and root meristems, the developing vascular tissues, and in the endosperm cells inside the testa.