Action of Light on Chlorophyll(ide) Appearance

The stimulating effect of a cold, dark pretreatment on the etioplast/chloroplast transformation of angiosperms. I. The stimulating effect of cold predarkening on different stages of greening under white light

“…4); there is no change in these effects when the dark phases are extended from 6 to 24 h. In contrast to samples exposed to 3" or 33°C there is a significant decrease in the capability of greening caused by an increase in the lengths of ternatively, detached at the very end of the white light phase, we obtained no support for the assumption that the decline of the curves (13"C/23"C) in Fig. 4 is caused by an accelerated senescence in the detached leaves (Kasemir andMohr 1982, Wardley et al 1984). Further experiments are in progress to elucidate this problem.…”

“…A short red light irradiation given a few hours before the onset of continuous white light eliminates the 'lag phase' (Virgin 1957(Virgin , 1958(Virgin , 1961. But also stage 111 in the process of greening can be stimulated by phytochrome (Pfr) (Kasemir 1983a, Kasemir et al 1973, Sopory and Rajasekhar 1986, Virgin 1957. Not only the P,,-mediated PChl(ide)-formation in darkness (Virgin 1955), but also the Chl(ide) formation under continuous white light (Lubimenko and Hubbenet 1932, Virgin 1955, Virgin and EgnCus 1983 are stimulated by increasing temperatures within the physiological temperature regime.…”

Biogenesis of thylakoid membranes with emphasis on the process in Chlamydomonas

“…In etiolated higher plants the initial burst of Chl a synthesis is followed by a lag of variable length, depending upon the prior treatment of the plant, and then both Chl a and Chl b accumulate at proportional rates (Koski 1950, Oelze-Karow andMolar 1978). In this sequence, Chl b is not made until Chl a achieves a 'threshold' level (Kasemir 1983). Whereas Chl a synthesis requires light, formation ofChl b seems to depend upon the presence of Chl a rather than directly on light.…”

Pigments in Vegetables

“…Only two uncommon plant tissues, a soybean callus culture and the greening skin of cold-stored potatoes, showed ALA synthetase activity (Wider de Xifra et al, 1971;Ramaswamy and Nair, 1973Battle et al, 1975). Recent findings of ALA synthetase activity consider the Shemin pathway contributing to the synthesis of nonplastid tetrapyrroles (Kasemir, 1983).…”

“…Upon illumination, the absorption maximum in vivo is shifted within 30 s from 635 nm to 678 nm. The process is complex, because various transient intermediate pigment-protein species with different spectroscopic properties are formed (Kasemir, 1983). The greening process was studied on etiolated seedlings that originate from seeds germinated in the dark, which are pale yellow rather than green, as are light-grown plants.…”