Chloroplast biogenesis 51 : modulation of monovinyl and divinyl protochlorophyllide biosynthesis by light and darkness in vitro.

It is shown that the monovinyl and divinyl protochlorophyllide biosynthetic patterns of etiolated maize (Zea mays L.), and cucumber (Cucumis sativus L.) seedlings and of their isolated etiochloroplasts can be modulated by light and darkness as was shown for green photoperiodically grown plants (E. E. Carey, C. A. Rebeiz 1985 Plant Physiol. 79: 1-6). In etiolated corn and cucumber seedlings and isolated etiochloroplasts poised in the divinyl protochlorophyllide biosynthetic mode by a 2 hour light pretreatment, darkness induced predominantly the biosynthesis of monovinyl protochlorophyllide in maize and of divinyl protochlorophyllide in cucumber. When etiolated seedlings and their isolated etiochloroplasts were poised in the monovinyl protochlorophyllide biosynthetic mode by a prolonged dark-pretreatment, light induced mainly the biosynthesis of divinyl protochlorophyllide in both maize and cucumber.