1988. The stimulating effect of a cold, dark pretreatment on the etioplastkhloroplast transformation of angiosperms I. The stimulating effect of cold predarkening on different stages of greening under white light. -Physiol. Plant. 72: 541-546.The etioplastkhloroplast transformation in angiosperms is controlled by light; most of the processes are mediated by phytochrome. We have shown that in the primary leaves of etiolated seedlings of wheat (Triticum aestivum L. cv. Kolibri), fire-bean (Phmeolus multijlorus L. cv. Preisgewinner) and in the cotyledons of etiolated sun flower seedlings (Helianthus annuus L. cv. macrocarpa) the chlorophyll accumulation in the phase after the end of the lag phase can be greatly stimulated by a cold predarkening period. This effect is not necessarily coupled with a red preirradiation. Furthermore the lag phase can be dramatically shortened by the cold, dark pretreatment, whereas the amount of photoconvertible protochlorophyll(ide) in the darkness remains unaffected by the cold, dark pretreatment. The stimulating effect of a cold, predarkening period on greening is fully reversible by a warm, dark phase that is placed between the cold period and the onset of the continuous white light phase. These findings cannot be generalized: We could demonstrate that in the tropical plant Momordica charantia greening under white light was not affected by different temperature pretreatments during predarkening. The stimulating effect of a cold, predarkening period on greening is assumed to have ecological relevance.