In vitro plant cultures

Although plant tissue culture should refer only to those of unorganized aggregates of cells, it is commonly used as a collective term to describe all types of in vitro plant cultures (George and Sherrington, 1984). 

DC246 Netien, G., and J. Combet. Phenolic acids present in in vitro plant tissue cultures compared to the original plant. C R Acad Sci Ser D 1971 272 2491-2494. 

Lor most of this work, optimised in vitro plant cell suspension cultures were used, especially from R. serpentina and C. roseus, and in the latter case, differentiated tissue (seedling) was also successfully used for investigation of various aspects of vindoline biosynthesis [12, 13]. 

Wink, M. 1987. Site of lupanine and sparteine biosynthesis in intact plants and in vitro organ cultures. Z. Naturforsch. 42, 868-872... 

The whole plant of Swertia japonica Makino (Gentianaceae) is an important bitter stomachic in Japan where it is called "senburi". The plant is also claimed to be effective in the treatment of hepatitis (57). Components of this plant such as the bitter secoiridoids (58-63), phenyl glucosides (64), flavonoids (65) and xanthones (66-68) have been intensively studied mainly by Japanese researchers but, to date, there are few reports on the production of these constituents in vitro. Callus culture produced no bitter principles (secoiridoids) (69, 70), xanthones and flavones but coumarin derivatives, scopoletin and its glucoside were detected (71). 

The early approaches employed to boost secondary metabolite yields using in vitro plant cell or organ cultures included, selection of nutrient regimes, choice of culture systems and conditions, level of plant growth regulators, cell line selection, precursor feeding, culture elicitation, removal of end-product, culture differentiation, etc. These were successfully followed by the application of recombinant DNA... 

The isoquinoline alkaloid contents in the transformed and non-transformed plants are indicated in Table 16. Alkaloid contents in the leaves were higher than those in the roots despite transformation. Cephaeline was the major alkaloid in all parts of in vitro plants as well as the root cultures. Alkaloid contents in the transformed plants, both in the leaves and roots, were lower than those of non-transformed plants except emetine in the roots. Any advantageous effects of T-DNA integration into ipecac on the alkaloid accumulation in the regenerated plants were not observed as previously reported for Duboisia hybrid [79] and Hyoscyamus muticus [103]. 

Phytoplasmas can be eliminated from their plant hosts, as they are generally thermo-labile and are not present in the shoot meristem (Lee and Davis, 1992). Furthermore they are sensitive to some antibiotics such as tetracycline (Ishiie et al., 1967 Heintz, 1989). Several methods have been applied to clean plant material for phytoplasmas these include in vitro tissue culture such as shoot tip (Dale and Cheyne, 1993) or micropropagation (Davies and Clark, 1994) sometimes in combination with heat or antibiotic treatment. 

Most technical experiences are based on plant cells. This may be explained by the fact that the majority of all commercial flavour extracts is of plant origin. Compared to intact freely grovm plants the in-vitro plant cell culture has advantages because... 

Within the last 10 years a great number of plants have been screened for antitumour active alkaloids. The two major groups involved in this search were the National Cancer Institute and a group of chemists and biologists at Eli Lilly and Co. Crude extracts and crystalline alkaloids were screened in vitro (cell cultures) and in vivo against sarcoma 180, Walker 256 intramuscular carcinosarcoma, Eagle s K.B. strain of human carcinoma of the nasopharynx, Lewis lung carcinoma, etc. The tests, which were reproducible, were made under standard conditions set up by the C.C.N.S.C. (Cancer Chemotherapy National Service Centre). 

Forty four alkaloids were newly isolated from the 22 lupin plants and the structures were elucidated in our recent study. The structures were determined by spectroscopic investigations, in particular, by extensive 2D-NMR experiments in the recent works, and by chemical transformation. Biosynthetic pathways are also proposed, in some cases, by the preparation of isolated enzymes and by in vitro cell culture system. Chemotaxonomic relationships of the lupin plants are discussed based on the structural classification of alkaloids. 

Finally, another important hormonal factor (but not the last) is the abscisic acid (ABA). This compound is produced mainly in chloroplasts. Its main functions are stomata closure, seed dormancy and the inhibition of axiUaiy buds growth. The addition of ABA to in vitro embryogenic cultures inhibits the early embryo germination and stimulates the coordinated maturation of the somatic embryo. However, prolonged exposition to ABA, this element suppresses growth of the formed in vitro plants (Bozhkov et al., 2002). 

Kevers, C Gaspar, T. Dommes, J. (2002). The beneficial role of different auxins and polyamines at successive stages of somatic embryo formation and development of Panax ginseng in vitro. Plant cell. Tissue and Organ Culture, Vol.70, No.2, pp. 181-188, (August 2002), ISSN 0167-6857... 

Shehata, A.M. Wannarat, W. Skirvin, R.M. Norton, M.A. (2010). The dual role of carbenicillin in shoot regeneration and somatic embryogenesis of horse radish Armoracia rusticana) in vitro. Plant Cell, Tissue and Organ Culture, Vol.102, No.3, (March 2010), pp. 397-402, ISSN 1573-5044... 

Han, J.S. Kim, S.K. Kim, S.W. Kim, Y.J. (2001). Effects of shading treatments and harvesting methods on the growth of Eleutherococcus sentkosus Maxim. Korean Journal of Medicinal Crop Science, Vol.9, No.l, pp. 1-7, ISSN 1225-9306 Han, J.Y. Choi, Y.E. (2003). Mass production of Eleutherococcus senticosus plants through in vitro cell culture. Korean Journal of Plant Biotechnology, Vol.30, No.2, pp. 167-172, ISSN 1598-6365... 

Micronutrients Micronutrients play an important and sometimes a crucial role in normal plant growth and development. Deficiency symptoms arise in plants that are grown under sub-optimal levels of micronutrients. As such, the tissue culture media are also formulated with the inclusion of essential micronutrients. However, in depth studies of their influence on in vitro cell culture, particularly microspore embryogenesis, are limited. This neglect is in spite of their absolute requirement for many physiological and biochemical cellular processes, including the catalysis of enzymatic reactions. Two of the micronutrients that... 

In the context of this pap>er, in vitro plant recalcitrance is defined as the inability of plant tissue cultures to respwnd to in vitro manipulations. In its broadest terms, tissue culture recalcitrance also concerns the time-related decline and/ or loss of morphogenetic competence and totipwtent capacity (Benson, 2000). 

Cucurbitacins are reported to possess growth-regulating activity in plants (Mandava, 1979). In animals, they exert cytotoxic activity and are purgatives. Cucurbitacin E gluco-side, from Gratiola officinalis (Scrophulariaceae) has cardiotonic activity (Wagner, 1988). Cucurbitacins from several plants have cytotoxic activity and antitumor properties (Blasko and Cordell, 1988). Cucurbitacin F (49) is cytotoxic in the KB and P-388 in vitro cell culture lines. 

The results of the tracer studies including the elucidation of the stereochemistry involved, provided a firm basis for a biochemical approach to PA biosynthesis, i. e., characterization of the enzymes that catalyze biosynthetic key steps and the specific mechanisms involved in translocation,subcellular accumulation, and metabolism of PAs. Early tracer work was carried out with intact plants to which tracers were applied for days or weeks. Meanwhile, in vitro plant systems, such as cell cultures and root-organ cultures of PA-producing plants are available. Root cultures were found to be excellent systems for biochemical and enzymatic studies of PA biosynthesis [20-22]. Dedifferentiated cell cultures do not synthesize PAs, but retain the ability to accumulate PAs. They are excellent systems to study the membrane transport of PAs and to identify the subcellular storage sites. 

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