THE INTRACELLULAR DISTRIBUTION OF SOME METALLIC ELEMENTS IN LEAVES

Abstract

S tocking , C. R alph , and A lpaslan O ngun . (U. California, Davis.) The intracellular distribution of some metallic elements in leaves. Amer. Jour. Bot. 49(3): 284–289. Illus. 1962.—A comparison of the potassium, sodium, calcium, magnesium, and nitrogen levels of chloroplasts isolated in an aqueous sucrose medium and by the nonaqueous method reveals that large amounts of these elements are lost from the plastids during their isolation in sucrose solution. Nonaqueously isolated chloroplasts of bean and tobacco leaves contained over 40% of the total leaf potassium, magnesium, and calcium. High levels of nitrogen up to 70% of the total leaf nitrogen were found associated with nonaqueously isolated chloroplasts. As much as 40–50% of this nitrogen is lost when chloroplasts are isolated in a sucrose solution. Electron photomicrographs of nonaqueously isolated chloroplasts reveal only a partial disruption of the internal structure and a loss of the plastid membrane during isolation.