Suspension cultured cells

Wagner V. Matthysse A. G. (1992) Involvement of a vitronectine-like protein in attachment of Agrobacterium tumefaciens to carrot suspension culture cells // J. Bacteriol. V. 174. P. 5999-6003. 

Our two network model of the primary wall receives support from a variety of indirect observations. For example it has been shown Aat when a cell wall is regenerated by a carrot protoplast a homogalacturonan/ rhamnogalacturonan shell is laid down first, through which the cellulose/ hemicellulose network is later intercalated (8). Further evidence that pectin may form an independent network is seen in the fact that walls from suspension-cultured cells of tofnato Lycopersicon esculentum VF 36),... 

Schaumann, A., Bruyant-Vannier, M.-P., Goubet, F., and Morvan, C. (1993) Pectic metabolism in suspension-cultured cells of flax, Linum usitatissimum. Plant Cell Physiol. 34 891-897. 

The possibility that the initial degree of methyl-esterification might be controlled by the properties of the methyltransferase enzymes was examined partial characterisation of these enzymes in suspension-cultured cells of fiax. Pectin methyltransferases beii enzymes characteristic of the Golgi apparatus [22], microsomes were fiactionated daily for ten days from suspension-cultured flax cells and incubated in the presence of C-SAM, the universal donor of methyl groups. 

PECTIN METHYLTRANSFERASES FROM SUSPENSION-CULTURED CELLS AND SEEDLINGS OF FLAX Linunt mitatissimum L. ). 

Flax seeds were placed for germination on moist paper for three days at 22°C and in the dark then, the plantlets were transferred under continuous white light on a liquid culture medium, as previously described [6], Suspension-cultured cells of flax were obtained from hypocotyl-derived calli as described by Schaumann et al. [4] and cultured on a medium described by Murashige and Skoog [7] containing kinetin (0.75 mg 1 ) and 2-4 D (0.2 mg 1 ). 

PMT activity measured without any exogeneous substrate fi om flax seedling microsomes was generally higher at pH 5 than at pH 7 (table 1) which was not the case in the suspension-cultured cells (see fig. 1). The activity was the most important in the cotyledons and particularly low at pH 7 in the hypocotyls. Whatever the pH, the activity increased over the culture duration. 

Figure 2 show that the specific activity fi om the cotyledons (mean value 38,200 and 13,900 dpm mg protein at pH 5.5 and 7 repectively) was also larger than from hypocotyls (21,300 and 7,500) or roots (18,600 and 10,500). Whatever the pH, two peaks occured in the cotyledons (days 3 and 9) while the specific activity was slightly increasing in the roots, during the culture. In the hypocotyls, the activity was rather constant at pH 5.5 and presented two peaks at neutral pH. In all cases, the specific activity was larger than that of suspension-cultured cells which had been estimated in the range of 250 and 2500 dpm mg" protein. 

Misaki, R., Fujiyama, K. and Seki, T. (2006) Expression of human CMP-V-acetylneuraminic acid synthetase and CMP-sialic acid transporter in tobacco suspension-cultured cell. Biochemical and Biophysical Research Communications, 339 (4), 1184—1189. 

Cells in vivo exist either attached to a surface or free in suspension. Adherent cell lines originate from cells of solid tissue. Breast carcinoma cell lines (such as MCF7, T47D, and SK-BR-3) are adherent cultures, and these cells are grown on the surface of plastic flasks that have been treated to facilitate adhesion (see Fig. 6.2). Suspension culture cell lines originate from cells that exist in suspension, such as those cells present in the blood and the lymphatic system (see Fig. 6.3). 

Ali MS, Nishimura M, Mitsui T, Akazawa T. Isolation and characterization of Golgi membrane from suspension-cultured cells of sycamore (Acerpseudoplatanus L.). Plant Cell Physiol 1985 26 1119-1133. 

DC 196 Kleinig, H., and C. Kopp. Lipids, lipid DC208 turnover, and phospholipase D in plant suspension culture cells (Daucus carota). Planta 1978 139(1) 61-65. 

Fischer, M., Wegryzn, T. F., Hallett, I. C., Redgwell, R. J. (1996). Chemical and structural features of kiwifruit cell walls comparison of fruit and suspension-cultured cells. Carbohydr. Res., 295, 195-208. 

Sims, 1. M., Munro, S. L. A., Currie, G., Craik, D., Bacic, A. (1996). Structural characterisation of xyloglucan secreted by suspension-cultured cells oiNicotianaplumbaginifolia. Carbohydr. Res., 293, 147-172. 

Yotsushima, K. Mitsui, T. Hayakawa, T. Purification of phosphoinositol kinase from suspension-cultured cells of rice (Oryza sativa L.). Biosci. Biotech-nol. Biochem., 59, 1953-1955 (1995)... 

Henstrand JM. 1992. Light and fungal elicitor induce 3-deoxy-D-arabino-heptulonosate 7-phosphate synthase mRNA in suspension cultured cells of parsley (Petroselinum crispum L.). Plant Physiol 98 761-763. 

PAL cDNA clones have been isolated from a number of species (Table 1). The first PAL cDNA clone was isolated from French bean suspension culture cells treated with fungal elicitor (Edwards et al., 1985). The clones were preselected by differential hybridisation to RNA from non-treated and elicitor-treated suspension culture cells. Further identification involved in vitro translation of hybrid-selected RNA and immunoprecipi-tation (Edwards et al., 1985), using an antibody raised against the purified bean PAL enzyme (Bolwell etal., 1985). This work identified pPAL5 as a PAL cDNA clone. 

Fig. 2. Binding of a nuclear extract to the ARE probe. A four copy radioactively labelled ARE probe was incubated with a nuclear extract from maize suspension culture cells. From the left the lanes represent free probe probe plus extract probe plus extract competed with a 10-fold excess of unlabelled ARE and, lastly, with a 50-fold excess of unlabelled ARE. The top bands are competed by unlabelled ARE but not by other unlabelled DNAs.

For suspension cultures, cell injury can occur due to the disruption of ascending bubbles or of those associated with the foam accumulated at the surface. Many additives, such as serum and the surfactant Pluronic F68, have been employed since the 1950s to protect cells from fluid-mechanical forces. 

Kauss, H. and Jeblick, W. 1991. Induced calcium uptake and callose synthesis in suspension-cultured cells of Catharanthus roseus are decreased by the protein phosphatase inhibitor okadaic acid. Physiol. Plant. 

Co-mediation of oligosaccharides and MJ has been demonstrated in the rice system in the induction of phytoalexins [100]. Exogenously applied MJ to elicited cells increased production of momilactone A to levels higher than those elicited with AT-acetylchitoheptaose alone. In suspension-cultured cells of parsley the influence of MJ on elicitation using cell walls of Phytophtora megasperma (Pmg elicitor) and chitosan was demonstrated [101]. These results suggested MJ conditioned the parsley suspension cells in a time-dependent manner to become more responsive to elicitation. 

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