Hairy roots of Datura candida×D. aurea: effect of culture medium composition on growth and alkaloid biosynthesis.

A transformed root clone of Datura candida×D. aurea was established following infection with Agrobacterium rhizogenes strain A4. This clone was examined for its growth and hyoscyamine and scopolamine content under various culture conditions. Among the three basal culture media tested, half-strength Gamborg's B5 medium supplemented with 5% sucrose was the best for root growth (288 mg dry weight/flask) and full-strength B5 medium for hyoscyamine and scopolamine content (0.36 and 0.17% dry weight, respectively). Experiments with exogenous nitrate added to the medium revealed that the biomass increased (353 mg dry weight/flask) and the hyoscyamine content improved remarkably (0.54% dry weight), but that the scopolamine content was significantly reduced. The addition of various precursors at two different concentrations did not significantly modify root growth. Feeding (R,S)-phenyllactic acid stimulated the biosynthesis of both alkaloids, whereas the addition of ornithine specifically reduced the scopolamine content.

Production of diosgenin by hairy root cultures ofTrigonella foenum-graecum L.

Hairy root cultures ofTrigonella foenum-graecum L. were established withAgrobacterium rhizogenes strain A4. The hairy roots produce diosgenin, an important spirostanol for the semi-synthesis of steroid hormones. Fourteen different liquid media were investigated. The fastest growth was obtained in McCown's woody plant (WP) medium supplemented with 3% sucrose; the highest diosgenin content was observed in half-strength WP medium with 1% sucrose (0.040% dry weight), which represents almost twice the amount detected in the 8-month-old non-transformed roots (0.024%). A time-course study in WP liquid media supplemented with 3% sucrose was undertaken. In these conditions, 17 µg diosgenin/g fresh weight were produced. The influence of cholesterol, medium pH and chitosan on diosgenin production was tested. The addition of 40 mg/l chitosan elevated the diosgenin content to three times that found in non-elicited hairy roots.

Production of valepotriates by hairy root cultures of Centranthus ruber DC.

Hairy root cultures of Centranthus ruber DC. were established by infection of sterile plantlets with Agrobacterium rhizogenes, strain R1601. The transformed roots were grown in 12 different, hormone-free liquid media, and valtrate, isovaltrate, 7-desisovaleroyl-7-acetylvaltrate, 7-homovaltrate, didrovaltrate and isovaleroxyhydroxydidrovaltrate were quantified by high performance liquid chromatography. The highest overall valepotriate content (3.0% dry wt) was observed in half-strength Gamborg B5 medium supplemented with 3% sucrose. This concentration is very similar to that found in the roots of parent plants grown in the field. The use of N,N-dimethylmorpholinium iodide, a plant bioregulator, was very detrimental to the hairy root growth and to the valepotriate production. The hairy roots cultured in half strength Gamborg B5 liquid medium supplemented with 3% sucrose for 45 days produced over 31 mg/g dry wt valepotriates.

Flavonoids from Iochroma gesnerioides.

Two aglycones (kaempferol and quercetin) and three glycosides (isoquercitrin, kaempferol 3-sophoroside and quercetin 3-sophoroside) were isolated from Iochroma gesnerioides (Kunth) Miers (Solanaceae). Whereas the aglycones are common for the Solanaceae, their 3-sophorose derivatives are found only in three genera of this family. Their isolation and identification (mainly by 1H- and 13C-nmr) are reported here.

Tropane Alkaloids in Transformed Roots of Datura quercifolia.

Hairy root cultures of DATURA QUERCIFOLIA were established following infection with AGROBACTERIUM RHIZOGENES strain LBA 9402. Eight tropane alkaloids were identified in the hairy roots, hyoscyamine being the major constituent. The growth and the hyoscyamine content of transformed roots were investigated under various conditions. Gamborg B5, Murashige and Skoog, and Woody Plant media were tested. Gamborg B5 medium was the best for growth as well as for hyoscyamine accumulation. The influence of sucrose concentration was examined and a 5% concentration was found to be the most appropriate for growth and for alkaloid production. After 35 days of incubation in this medium, the hyoscyamine content of the roots was 1.24% based on dry weight. The influence of gibberellic acid and of Amberlite XAD-4 resin on hyoscyamine production was tested.

High-yield production of valepotriates by hairy root cultures of Valeriana officnalis L. var. sambucifolia Mikan.

Hairy root cultures of Valeriana officinalis var. sambucifolia were established by infection of sterile plantlets with Agrobacterium rhizogenes strain R1601 The transformed roots were grown in 10 different, hormone-free liquid media and the isovaltrate, valtrate, didrovaltrate, isovaleroxyhydroxydidrovaltrate content was quantified by HPLC. Valepotriates were entirely retained inside the root tissues. The highest overall valepotriate content (10.3 % dry wt), 4 times the amount found in the roots of 9-month-old nontransformed plants, was observed in half strength Gamborg B5 medium supplemented with 2 % sucrose. The hairy roots cultured in Murashige and Skoog liquid medium supplemented with 2 % sucrose for 50 days produced over 44 mg/g dry wt valepotriates.

Flavonoids from Lycium halimifolium1.

Five flavonol glycosides and two genins have been isolated from the leaves of LYCIUM HALIMIFOLIUM Mill. (Solanaceae): quercetin 3- O-rutinoside-7- O-glucoside ( 1), kaempferol3- O-rutinoside-7- O-glucoside( 2), rutin ( 3), nicotiflorin ( 4), isoquercitrin ( 5), quercetin ( 6), and kaempferol ( 7). They were identified on the basis of acid and enzymatic hydrolysis and spectral data.