Kinetin-induced chloroplast maturation in cultures of tobacco tissue.

Cultured tobacco tissue possesses proplastids capable of differentiating into mature chloroplasts. Kinetin (6-furfurylaminopurine) is a specific requirement for this differentiation; the absence of this compound results in a blockage of the formation of grana. The possibility that kinetin exerts a direct effect upon chloroplast differentiation is considered.