Tissue callus

In the appropriate culture medium, tissue explants give rise to callus tissue. Callus tissue is comprised of large, thin-walled parenchyma cells. It is similar to the undifferentiated tissue produced by plants as a repair mechanism when they are injured. In tissue culture, dedifferentiated callus can be induced to form plantlets that grow into normal plants. The induction of callus occurs when a sterile explant is brought into contact with a nutrient medium, which contains substances that initiate cell division and support growth. An explant may be a uniform piece of tissue or tissue derived from different cell types (Yeoman, 1973). Storage parenchyma tissue from Jerusalem... 

Yeoman, M.M., Tissue (callus) cultures techniques, in Plant Tissue and Cell Culture, Botanical Monograph 11, Street, H.E., Ed., Blackwell, Oxford, 1973, pp. 31-58. 

Attempts have been made to determine the factors through which the endosperm engages in the development of the embryo. The experiments carried out amount, in principle, to replacing the endosperm with culture media containing defined supplements. Tissues, organs, or whole plants, e.g. even the embryo, are then cultivated on these media. Fig. 199 shows how organs (root and apical meristem) and tissues (callus from... 

Aside from chemical methods, several patents have appeared on the biochemical production of natural vitamin from callus tissue cultures (41). 

Ralstonia eutropha (Alcaligenes eutrophus) strain NH9 is able to degrade 3-chlorobenzene by the modified ortho pathway. The cbnA gene that encodes 3-chlorocatechol-l, 2-dioxygenase was introduced into rice plants (Oryza sativa -p.japonicd) under the control of a virus 35S promoter. 3-Chlorocatechol induced dioxygenase activity in the callus of the plants, and leaf tissues oxidized 3-chlorocatechol with the production of 2-chloromuconate... 

Within each species, individual promoters resulted in distinct, tissue-dependent accumulation patterns. The cauliflower mosaic virus (CaMV) 35S promoter, for example, led to high-level accumulation in callus and leaves whereas the maize ubiqui-tin-1 promoter was the best choice for producing recombinant proteins in cereal seeds even though it is not in itself seed-specific [23]. The lack of such comparative studies for proteins other than rAbs makes it difficult to generalize an optimal expression strategy for all proteins. Tables 7.1 and 7.2 list recombinant proteins expressed in plants and provide details of the production system, promoters and other regulatory elements used in each case. 

Some studies indicated that exogenous zearalenone influences plant growth and development. For example, zearalenone stimulated the initiation of the vegetative bud in tobacco pith callus tissue (Mirocha et al. 1968), inhibited the cell membrane transport of maize roots (Vianello and Macri 1981) and enhanced the a-amylase and P-glucosidase activities of germinating maize seeds. 

Todd reported that the respiration of pinto bean leaves was stimulated by exposure to ozone (at 4 ppm for 40 min). The first measurements were 4 h after the ozone exposure. The respiration rate later declined to the control value. In all cases, increased respiration correlated well with visible injury. MacdowalP confirmed these results, but made an additional observation during the first hour after ozone exposure (at 0.7 ppm for 1 h), and before visible symptoms appeared, respiration was inhibited. The increase in respiration took place only later, when visible symptoms appeared. Dugger and Palmer" reported an increase in respiration in lemon leaf tissue after 5 days of exposure to ozone at 0.15-0.25 ppm for 8 h/day. They reported no morphologic changes at that time. Anderson and Taylor S found that ozone induced carbon dioxide evolution in tobacco callus tissue. The threshold for evolution was about 0.1 ppm for 2 h in the sensitive Bel W,. The ozone concentration required for maximal carbon dioxide evolution was about twice as much in the more resistant cultivar. Formation of roots decreased sensitivity. 

Feung, C. S., Hanrilton, R.H., and Mumma, R.O. Metabolism of 2,4-dichlorophenoxyacetic acid. V. Identification of metabolites in soybean callus tissue cultures. J. Agric. Food Chem., 21(4) 637-640, 1973. 

Ochoa-Alejo N, Gomez-Peralta JE (1993) Activity of enzymes involved in capsaicin biosynthesis in callus tissue and fruits of duli pepper Capsicum annuum L.). J Plant Physiol 141 147-152... 

Cryptotanshinone (Fig. 4), a diterpene quinone, is produced in root tissues of Salvia miltiorrhiza Bunge plants. Of remarkable anti-inflammatory effect, a maximal yield of 4.6 0.1 mg of cryptotanshinone/g dw was detected in a 60-day-old callus of S. miltiorrhiza cultured in 0.2-mg/L N -benzyladenine-supplemented Murashige and Skoog medium. ... 

Thengane SR, Kulkami DK, Shrikhande VA, Joshi SP, Sonawane KB, Krishnamurthy KV. (2003) Influence of medium composition on callus induction and camptothecin(s) accumulation in Nothapodytes foetida. Plant Cell Tissue Organ Cult 72 247-251. 

Studies of conditions for the growth of callus tissue of C. roseus were first reported in 1962 (114) by Babcock and Carew, and analytical work commenced when Carew and co-workers (115) demonstrated that in the presence of 0.5 mg/liter kinetin callus tissue grew rapidly and probably produced vindoline (3), as well as a number of other alkaloids. At the same time, a group at Eli Lilly (116) reported an analysis of the alkaloids of crown gall cultures which had been maintained by Hildebrandt s group... 

It has taken many years, however, for a callus culture to be described which produces vinblastine (1). Success was achieved by Miura and coworkers 122) as a result of the screening of callus tissues with the HeLa cell line. Vinblastine (1) was detected at a level of 1 p,g/g dry weight by HPLC and characterized by retention time and mass spectrometry. This level is below that in the whole plant, and thus its presence was probably overlooked by previous workers. 

Continued work by the same group 123) has led to the first isolation of vinblastine (1) from a multiple shoot culture of C. roseus. The most productive line, MSC-B-1, consisted of two distinctly different tissues, multiple shoots and unorganized tissue, and was maintained growing and productive for 30 months. Vinblastine (1) was isolated by HPLC, and the content was estimated to be 15 jjig/g dry weight. Production of this alkaloid was greater than that in the callus culture but less than that observed for the parent plant, even though the levels of catharanthine (4) and vindoline (3) were about the same. 

The work by Scott and Lee 165) on the isolation of a crude enzyme system from a callus tissue culture of C. roseus was followed by studies of Zenk et al. on an enzyme preparation from a cell suspension system which produced indole alkaloids 166). The cell-free preparation was incubated with tryptamine and secologanin (34) in the presence of NADPH to afford ajmalicine (39), 19-epiajmalicine (92), and tetrahydroalstonine (55) in the ratio 1 2 0.5. No geissoschizine (35) was detected. In the absence of NADPH, an intermediate accumulated which could be reduced with a crude homogenate of C. roseus cells in the presence of NADPH to ajmalicine (39). Thus, the reaction for the formation of ajmalicine is critically dependent on the availability of a reduced pyridine nucleotide. 

Antiglaucomic activity. Water extract of the callus tissue, administered intravenously to rahhits at a dose of 250 pg/animal, produced a 55% drop in intraocular pressure . ... 

NT366 Chirek, Z. Physiological and biochemical effects of morphactin IT 3233 on callus and tumor tissues of Nicotiana tahacum cultured in vitro. III. Transamination process catalyzed by NT376 aminotransferase 1 -alanine 2-oxogluta-rate. Acta Soc Bot Pol 1974 43 169. 

P. Aksenova. Study of histones of calluses with vegetative and generative morphogenesis in trapezoid tobacco. Dokl AkadNauk SSR 1974 216 226. Ackermann, L. Evidence of a glycoprotein, until now unknown, in tissue culture of hlicotiana tabacum. C R Seances Soc Biol Ses Fil 1974 168 344. 

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