A cotyledon slice system for the electron autoradiographic study of the synthesis and intracellular transport of the seed storage protein of Vicia faba

Abstract

Cultured slices of cotyledon tissue from 60-day broad bean have been shown to synthesise globulin protein extensively. About 80% of the (3)H-leucine incorporated into protein was incorporated into globulin protein; (35)S-sulphate was also incorporated by the slices.The rate and dependence of the incorporation on the quantity of radiochemical added and the volume of culture medium were also demonstrated. It was concluded that the cotyledon slices maintained the in vivo behaviour during the period of the experiments.The slice system was used in an electron autoradiographic experiment. It was shown that grain counts were associated initially with the endoplasmic reticulum then moved to the protein bodies. It was concluded that globulin protein is synthesised by the ribosomes of the endoplasmic reticulum and then moves to the protein bodies; it was suggested that the process takes 25 min.