Tobacco cells

Very few self-sufficient viruses have only 60 protein chains in their shells. The satellite viruses do not themselves encode all of the functions required for their replication and are therefore not self-sufficient. The first satellite virus to be discovered, satellite tobacco necrosis virus, which is also one of the smallest known with a diameter of 180 A, has a protein shell of 60 subunits. This virus cannot replicate on its own inside a tobacco cell but needs a helper virus, tobacco necrosis virus, to supply the functions it does not encode. The RNA genome of the satellite virus has only 1120 nucleotides, which code for the viral coat protein of 195 amino acids but no other protein. With this minimal genome the satellite viruses are obligate parasites of the viruses that parasitize cells. 

The cell walls of the Solanaceae plant species contain the XXGG type of XGs [247,275]. Suspension-cultured tobacco cells secrete a XG, bearing disaccharide side chains (11) [276], as similarly reported for XGs of other solana-ceous plants. The XG from suspension-cultured tomato cells is more complex, as it also contains the unusual / -L-Ara/-(1 3)-o -L-Ara/-(1 2)-a-D-Xylp trisaccharide side-chain (12) in addition to the prevaiUng dimeric moiety (13) [277]. 

The rheological behavior of storage XGs was characterized by steady and dynamic shear rheometry [104,266]. Tamarind seed XG [266] showed a marked dependence of zero-shear viscosity on concentration in the semi-dilute region, which was similar to that of other stiff neutral polysaccharides, and ascribed to hyper-entanglements. In a later paper [292], the flow properties of XGs from different plant species, namely, suspension-cultured tobacco cells, apple pomace, and tamarind seed, were compared. The three XGs differed in composition and structural features (as mentioned in the former section) and... 

Protein increases Barley leaves (D) Tobacco cell cultures (S and PEG)... 

Ericson, M. Alfinito, S.H. (1984). Proteins produced during salt stress in tobacco cell culture. Plant Physiology, 74, 506-9. 

La Rosa, P.C., Hasegawa, P.M., Rhodes, D., Clithero, J.M., Watas, A.A. Bressan, R.A. (1987). Abscisic acid stimulated osmotic adjustment and its involvement in adaptation of tobacco cells to NaCl. Plant Physiology, 85, 174-81. 

Singh and co-workers (19876) found that tobacco cells selected to tolerate 500 mM NaCl when exposed to salt stress responded by synthesising... 

The 26 kDa protein synthesised by salt-adapted tobacco cells has been further characterised (Singh et al., 1987a). The protein makes up approximately 12% of the total cellular protein and has been resolved into two forms. These two forms have been designated osmotin 1 and osmotin II and occur in a 2 3 ratio. The forms are distinct with osmotin I soluble in an aqueous phase and osmotin II soluble in detergent. The proteins accumulate as inclusion bodies in the vacuole and are only sparsely distributed in the cytoplasm. 

Determination of free space, growth, solute concentration and parameters of water-relations of suspension-cultivated tobacco cells. Plant, Cell Environment, 9, 693-701. 

Heyser, J.W. Nabors, M.W. (1981). Growth, water content and solute accumulation of two tobacco cell lines cultured on sodium chloride, dextran and polyethylene glycol. Plant Physiology, 68,1454-9. 

Bressan, R.A., Singh, N.K., Handa, A.K., Kononowicz, A. Hasegawa, P.M. (1985). Stable and unstable tolerance to NaCl in cultured tobacco cells. In Plant Genetics, ed. M. Freeling, pp. 755-69. New York Alan R. Liss. 

Fig 5 Immunogold labelling on thin sections of low-temperature embedded cell walls from 9-day old tobacco cells with JIM 5, a monoclonal antibody that recognises a relatively unesterified pectic epitope. Cell walls of elongating cells label very weakly, but material that is being secreted into the culture medium labels strongly. The old part of the wall is labelled but new wall material is not. 

Arabinose Sycamore cell suspensions 15.2 Tobacco cell suspensions 2.6... 

Iraki, N.M., Singh, N., Bressan, R.A., and Carpita, N.C. (1989) Cell walls of tobacco cells and changes in composition associated with reduced growth upon adaption to water and saline stress. Plant Physiol. 91 48-53. 

McCann, M.C., Shi, J., Roberts, K., and Carpita, N.C. (1994) Changes in pectin structure and localization during the growth of unadapted and NaCl-adapted tobacco cells. Plants. 5 773-785. 

The presence of foreign protein in the medium of plant cultures does not necessarily mean that all or even most of the product can be recovered from the medium. In many expression systems where an appropriate signal sequence has been used, considerable amounts of foreign protein remain within the plant cells and/or tissues. For example, in a comparison of IgG antibody production in tobacco cell suspension and hairy root cultures, a maximum of 72% of the total antibody was found in the medium of the suspension cultures whereas only 26% was found in the medium of the hairy root cultures [17]. This result could indicate that secretion and/or transport across the cell wall was slower in the hairy roots alternatively, it could indicate poorer stability of the secreted protein in the hairy root medium. If foreign proteins are to be purified from the medium, improved secretion and extracellular product stability are desirable. 

The addition of 50-100 mM NaCI to tobacco cell suspensions reduced cell growth but resulted in a 50% increase in the maximum level of hGM-CSF secreted into the culture medium [40]. Intracellular hGM-CSF was relatively unaffected by this treatment. 

Other kinds of plant cell cultures such as immobilized tobacco cells have also been studied for the analogous transformation. The results show that plant cell cultures provide an accessible way of converting several prochiral ketones into the corresponding chiral secondary alcohols with reasonable chemical yield and high enantioselectivity. 

The study first attempted to elucidate whether the membranes of the Golgi cisternae of tobacco cells could be differentially stained by the ZIO method, and whether they were more clearly visible than the sec-... 

Vila, M., Pascal-Lorber, S., Rathahao, E., Debrauwer, L., Canlet, C., and Laurent, F. 2005, Metabolism of [C-14]-2,4,6-trinitrotoluene in tobacco cell suspension cultures. Environ. Sci. Technol. 39 663-672. 

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