BENZYLADENINE STIMULATES THE DEVELOPMENT OF MITOCHONDRIA IN WATERMELON COTYLEDONS

The development of mitochondria was followed for 5 days in watermelon cotyledons excised from the seedling 24 h after soaking and cultured in the dark on filter paper saturated with water or with a 10-4 M benzyladenine (BA) solution. Treatment with BA increases the total mass of mitochondria as shown by electron microscopy and by measurements of mitochondrial protein after density gradient centrifugation. Enzyme levels are increased to the same extent as total mitochondrial protein so that specific activities in mitochondria from treated cotyledons are the same as those in mitochondria from water controls. Only the specific activity of cytochrome oxidase and the specific content of cytochrome a3 are higher in mitochondria of BA-treated cotyledons. Mitochondria isolated from cotyledons treated with BA seem to be in a better state of preservation than those isolated from water controls. © 1979.