title: Lag-phase and rate of synthesis in light-mediated anthocyanin synthesis.
abstract: Mustard (Sinapis alba L.) seedlings were irradiated with continuous far-red light either with or without a pretreatment with 3 or 6 h of the same far-red light, separated by a 15 h dark period. The pretreatment increases the initial rate of anthocyanin accumulation - as caused by the 2nd light treatment - at least 6-fold but leads to an earlier cessation of anthocyanin accumulation. Moreover, the pretreatment seems to shorten the apparent lag-phase of anthocyanin accumulation considerably but it does not eliminate the lag. If the pretreatment with far-red light is terminated before the seedling reaches competence (with regard to phytochrome and anthocyanin synthesis) the pretreatment has no effect on the apparent lag-phase even though the future capacity of anthocyanin biogenesis is considerably stimulated by the pretreatment. The time course of induction of anthocyanin and that of phenylalanine ammonia-lyase (PAL) (Acton et al. 1980, Fig. 1) is in line with the concept that induction of PAL by light is a prerequisite for the onset of light-mediated anthocyanin synthesis.
authors.affiliation: Biologisches Institut II der Universität Freiburg, Schänzlestraß 1, D-7800, Freiburg, Federal Republic of Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Mohr