Photocontrol of C-glycosylflavones in barley seedlings

Acetylcholine Inhibition of Phytochrome-mediated Increases in a Flavonoid and in Phenylalanine Ammonia-Lyase Activity of Etiolated Barley Plumules

“…This latter response can be measured within a few seconds (4). Since we have reported both long and short term changes in flavonoid levels in barley plumules given a few min of red light (6) and have begun investigations on the role of PAL in the accumulation of barley phenolics, we investigated the effects of ACh and related cholinergic drugs, with and without red light, on levels of the flavonoid saponarin (6-C-glucosyl-7-O-glucosyl apigenin) and PAL in etiolated barley plumules (Hordeum vulgare L.).…”

“…Barley cultivars Harrison (saponarin data) or Atlas 68 (PAL data) were grown, irradiated, and harvested by published techniques (6). No varietal effects were detected in preliminary experiments.…”

“…All cultural, harvesting, and processing steps through the final centrifugation were carried out under a dim green safelight. Saponarin was determined by the method of McClure and Wilson (6) and PAL assayed by a technique modified from Zucker (8). Chemicals were obtained from Sigma Chemical Company, St. Louis.…”

“…Jaffe (personal communication, 1971) had suggested that these compounds might respond more readily in roots than in shoots, and that the coleoptiles surrounding the primary leaf at this developmental stage might offer a barrier to drug penetrance. In 5-day-old etiolated barley saponarin is restricted to the primary leaf (6) Early in the investigation of PAL levels we had concluded that ACh caused a slight but probably significant increase in enzyme. We then became aware of the work of Bardzik et al (2) on the effects of water stress on PAL levels in sections of maize leaf.…”

Diurnal periodicity of chalcone-synthase activity during the development of oat primary leaves

“…Flavonoid biosynthesis is controlled by several environmental parameters such as light (McClure and Wilson 1970;Weissenb6ck and Effertz 1975;Hrazdina and Creasy 1979;Hahlbrock 1981) and by the developmental program of the plant (Wiermann 1981). No generalization can be made concerning the influence of light on flavonoid metabolism: plant systems needing light as an essential prerequisite for flavonoid formation (DuellPfaff and Wellman 1982;Mancinelli 1984) and those which also produce flavonoids in the dark (Margna and Laanest 1984) have both been reported.…”