Jacques Homes

Traits of transgenic Atropa belladonna doubly transformed with different Agrobacterium rhizogenes strains

Hairy root cultures of Atropa belladonna L. were established by infection either with Agrobacterium rhizogenes ATCC 15834 or MAFF 03-01724, and transgenic plants were obtained from both hairy root cultures. Doubly transformed roots were induced by re-infection of the leaf segments of transgenic Atropa belladonna plants (A. rhizogenes 15834) with MAFF 03-01724. Shoots and viviparous leaves were regenerated from the doubly transformed roots. The genetic transformation was determined by the opine assay (agropine, mannopine and/or mikimopine) and polymerase chain reaction. Physiological changes and tropane alkaloid biosynthesis in the hairy roots (singly and doubly transformed) were investigated. The alkaloid content in the doubly transformed root strain was intermediate as compared to the root strains which were singly transformed. On the other hand endogenous IAA levels in doubly transformed roots were significantly decreased compared to both singly transformed roots.

High-speed countercurrent chromatography separation of taxol and related diterpenoids from Taxus baccata

Abstract Taxol and related taxane diterpenoids were isolated from pre-purified extracts of stem-barks of Taxus bacccata by HSCCC. The described method allowed to obtain a mixture of taxol and cephalomannine without any other interfering constituent and furthermore a partial separation of taxol (40 % of the total recovery) from cephalomannine. In addition, the HPLC and TLC separation conditions of these compounds for the semi-preparative and analytical purposes were improved. The proposed HSCCC method could be adapted to the scaling-up separation of taxol from vew material.

Production of quassinoids by tissue cultures of Ailanthus altissima

Abstract Callus cultures derived from a young shoot and a flower bud of Ailanthus altissima have been examined for quassinoid production (ailanthone). The biosynthetic potential of the calli from the two sources was related to the explant origin as well as to the addition of exogenous auxins to the culture medium. This is the first report of quassinoid production in cell culture.

Essential oil production by Anthemis nobilis L. tissue culture.

Summary The production of essential oil by tissue cultures of Anthemis nobilis L. including cell suspension, shoot and crown-gall cultures is reported. The biosynthetic capability of these different cultures was compared with that of plants grown in a field. The addition of crude polysaccharide fraction prepared from yeast extract and from the plant itself to shoot cultures affected the composition and total essential content (from 0.08 % to 0.30 % dry weight). The essential oil content of the crown-gall tissue of A. nobilis was 0.25 % of the dry weight and the composition of the essential oil was comparable to that of the flowers.

An unusual root tip formation in hairy root culture of Hyoscyamus muticus.

SummaryHairy root cultures of Hyoscyamus muticus were established using Agrobacterium rhizogenes ATCC 15834. In one out of 8 clones established, an unusual root tip formation was observed after transfer of cultures from half-strength Murashige and Skoog (1962) to Whites medium (1939). This phenomenon was associated with the production of a fine brownish cell suspension culture. Hairy root development resumed after transfer of the root tips from White to half-strength Murashige and Skoog medium. After plating the isolated brownish cells on hormone-free half-strength Murashige and Skoog or White solid medium, callus proliferation was observed, and then redifferentiation of hairy roots occurred. The polymerase chain reaction analysis of the H. muticus hairy root (clone Z2) revealed that only the tl region of the T-DNA was integrated. The growth and the production of five tropane alkaloids by this clone were examined.

Anthemis nobilis L. (Roman Chamomile): In Vitro Culture, Micropropagation, and the Production of Essential Oils

Anthemis nobilis L. (syn. Anthemis odorata Lamk.; Chamaemelum nobile L., All.; Chamaemelum odoratum Dod.; Chamomilla nobilis God.; Leucanthemum odoratum Eid. Ap.; Ormenis nobilis Gay), so-called Roman chamomile, is a perennial herb of the Asteraceae family. It is native to the southwest of Europe (France, Spain, and Portugal), and has spread all over the Europe. It is also present in southwest Asia (De Langhe et al. 1983; Bezanger-Beauquesne et al. 1986).

Control of Dioscorea alata microtuber dormancy and germination by jasmonic acid

Effects of appling exogenous jasmonic acid (JA) on the germination of Dioscorea alata L. microtubers were examined on Murashige and Skoog (MS) medium. Microtuber germination was promoted by JA (0.1 and 1 μM) supplemented to the culture medium but higher concentrations (30 and 100 μM) completely inhibited germination. When these inhibited microtubers were transferred to hormone-free medium, germination resumed.After transfer to greenhouse conditions, almost all plants (95%) from tubers previously cultivated on MS medium with 100 μM JA survived and all acclimatized plants had produced tubers after 8 months. It is concluded that depending on JA concentration, both the germination and dormancy processes in D. alata microtubers were affected. The release from dormancy is easily obtained by transferring dormant microtubers to hormone-free medium.

Alkaloids from callus cultures of Holarrhena floribunda

Abstract From callus cultures of Holarrhena floribunda a complex mixture of alkaloids has been isolated in small yield, the main alkaloid of which was identified as conessine by MS, GC and TLC.