Investigations have been carried out with the aim of producing secondary metabolites in vitro by cell cultures of Zanthoxylum zanthoxyloides. Cell dedifferentiation from explants was induced in the presence of 2,4-dichlorophenoxyacetic acid or 1-naphthaleneacetic acid in combination with benzyladenine. HPLC analyzes revealed the uneven accumulation, in diversity and quantity, of a number of secondary metabolites in these cell cultures. These secondary metabolites are not synthesized by all cell strains with the exception of hesperidin which is present everywhere. Quantification of hesperidin and chelerythrine showed that 2,4-dichlorophenoxyacetic acid inhibits their synthesis unlike 1-naphthaleneacetic acid and light which seem to stimulate it. This study shows that it is possible to produce secondary compounds in vitro by cell cultures of Zanthoxylum zanthoxyloides.

Literature reports that roots are source of important compounds possessing pharmaceutical properties. So, we have oriented our work toward the transgenic root establishment of O. basilicum obtained from Agrobacterium rhizogenes, a natural bacterium of the soil responsible for the formation of the "hairy root". This genetic transformation was achieved from the leaves and segments of stems allowed to initiate of abundant roots, displaying the typical characteristics of the hairy root syndrome, as a rapid growth on solid and in liquid media without hormones. The root initiation seems to arise from the target cells near to the inner and outer phloem after mother plant infection. A bacterial inoculation at the central nervure level of the leaves led to an efficient and original protocol of transformation. Indeed numerous transgenic root clones, from Ocimum explants, could be obtained.
Finally, the transformed state of the roots was confirmed by molecular analysis showing the obvious integration of the genes rol of A. rhizogenes responsible of the "hairy root" phenotype.

Nauclea diderrichii, is a forest species whose seeds germination is difficult in its biotope. Its overexploitation for its very resistant wood against the attacks leads to its disappearance in Togo. In vitro micropropagation trials were carried out for his faster and massive regeneration. In vitro seedlings apexes had been cultivated on four media (MS, ½ MS, WPM and ½ WPM). The high ionic concentration in macroelements in the culture medium is harmful to N. diderrichii's seedlings development. Complete Woody Plant Medium (WPM) (41,54mM) allowed a better growth of the seedlings during initiation phase. Among both cytokinins (BAP and Kinetin) used, BAP at 2 mg/L, has gave a better multiplication rate (13,65d ± 5.71 nodes/seedling). Among three auxins (IBA, NAA and 2,4-D) used at 0,1mg/L, IBA has gave seedlings with vigorous roots which are better appropriate for weaning, that those obtained with NAA. 2,4-D produced only calluses. The weaning of the seedlings, realized on vermiculite was succeeds at 100%. Thus fast and massive multiplication of N. diderrichii can be done in vitro on WPM added with BAP at 2 mg/L. IBA at 0,1mg/L is the auxin which is better appropriate for improvement of seedlings' rooting.