The production of sesquiterpene-type phytoalexins with a vetispyradiene skeleton by Hyoscyamus albus hairy roots induced by methyl jasmonate (MeJA) was reported in a previous paper. The production pattern on co-treatment with cupper sulfate and MeJA (CuSO(4)-MeJA) showed a TLC profile differing from that on treatment with MeJA. Thus, we studied the production of phytoalexins on hairy root cultu...

Hyoscyamine is epoxidized to scopolamine via 6beta-hydroxyhyoscyamine in several solanaceous plants. 6,7-Dehydrohyoscyamine has been proposed to be an intermediate in the conversion of 6beta-hydroxyhyoscyamine to scopolamine on the basis of the observation that this unsaturated alkaloid is converted to scopolamine when fed to a Datura scion. To determine whether a dehydration step is involved i...

Continued DNA synthesis in the generative cell nucleus, followed by mitosis and cytokinesis, results in the formation of pollen embryoids in cultured anthers of H. niger. In contrast, the nucleus of the vegetative cell undergoes no DNA synthesis after it is cut off, or synthesizes DNA only during a limited number of cell cycles. DNA synthetic patterns in the generative and vegetative cell nucle...

The purpose of the present study was to determine the tropane alkaloid content of four Hyoscyamus species from Iran, i.e. H. pusillus L., H. niger L., H. reticulatus L. and H. kurdicus Bornm. Determination of alkaloids was performed by the HPLC method. Samples were extracted with chloroform-methanol-25% ammonium hydroxide 15:5:1 (V/V/V). HPLC separation was performed on Eurospher C18 reversed p...

Four cDNAs for spermidine synthase (SPDS), which converts the diamine putrescine to the higher polyamine spermidine using decarboxylated S-adenosylmethionine as the co-factor, were isolated from Nicotiana sylvestris, Hyoscyamus niger, and Arabidopsis thaliana. When the N.sylvestris SPDS cDNA was expressed in a SPDS-deficient E. coli mutant, the recombinant protein showed high SPDS activity, but...

In the biosynthesis of tropane alkaloids, two tropinone reductases (TRs) catalyze reduction of tropinone to different stereoisomers, tropine and pseudotropine. Two TRs from Hyoscyamus niger have 64% of identical amino acids and hence a common evolutionary origin. In this study, genomic clones of TRs were isolated from H. niger. Their sequence comparison showed that although they have the same e...