amaranthus viridis/tyrosine

Ten species of plants from 8 families, grown as sterile cell cultures, were examined for their ability to degrade the aromatic ring of L-tyrosine and two of its metabolites, homogentisic acid and 3,4-dihydroxyphenylalanine (DOPA). All cultures showed low levels of tyrosine degradation (0.3-2.6% in

Tocopherols are lipid-soluble compounds synthesised exclusively by photosynthetic organisms. In this study, in vitro callus cultures were established from two plants that are naturally rich in tocopherols, Amaranthus caudatus and Chenopodium quinoa, in order to examine whether callus cultures were

The use of only the upper part of the hypocotyl and the cotyledons in the Amaranthus tricolor bioassay for cytokinins, instead of the whole seedling, was found to reduce the endogenous response and give a higher benzyladenine-dependent response. There is no marked difference in the uptake or

"Aging" of excised cotyledons plus the top part of the hypocotyl of Amaranthus tricolor seedlings was carried out by washing in distilled H(2)O for varying periods. This led to increased betacyanin accumulation during the subsequent 24-hour induction period in the presence of tyrosine and Na(+) +

Gibberellic acid inhibition of betacyanin biosynthesis has been studied in Amaranthus caudatus L. using the pigment precursors L-tyrosine and L-dihydroxyphenylalanine. Precursors fed to gibberellic acid (GA) treated seedlings completely recovered betacyanin synthesis while the GA induced growth

Betalains are a group of nitrogen-containing pigments that color plants in most families of Caryophyllales. Their biosynthesis has long been proposed to begin with hydroxylation of L-tyrosine to L-DOPA through monophenolase activity of tyrosinase, but biochemical evidence in vivo remains lacking.

Potassium ions at low concentrations stimulate cytokinin-dependent betacyanin synthesis in Amaranthus tricolor seedlings more than other alkali metal ions when tested as the chloride salts. The sequence of relative stimulation is K(+) > Rb(+) > (Na(+) = Li(+)). Calcium and Mg(2+) ions are inhibitory

A key enzyme of the shikimate pathway, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS; EC 2.5.1.19), is the known target of the widely used herbicide glyphosate. Glyphosate resistance in Amaranthus palmeri, one of the most troublesome weeds in agriculture, has evolved through increased EPSPS

Isolated hypocotyls synthesize betacyanin after light exposure in Amaranthus caudatus L. Pigment synthesizing capacity is reduced in the hypocotyls with increased incubation of seedlings in dark after 24h. External feeding of precursors of betacyanin L-tyrosine and DOPA enhances pigment synthesis in

The composition and content of secondary compounds produced by the shikimate pathway and the contents of protein and cellulose were determined in leaves of amaranth (Amaranthus tricolor L.) K-99 and the cultivar Valentina raised from it by family selection and enriched in the pigment amaranthine. It