Transgenic tobacco

CAD-Deficient Angiosperms The availability of a C-enriched lignin from a CAD-deficient tobacco transgenic [71] and a series of model compounds [335] allows NMR methods to be used to ascertain hydroxycinnamaldehyde in vivo... 

Saito, K., Hamajima, A., Ohkuma, M., Murakoshi, I., Ohmori, S., Kawaguchi, A., Teeri, T.H. and Cronan, J.E. (1995) Expression of the Escherichia coli fabA gene encoding p-hydroxydecanoyl thioester dehydrase and transport to chloroplasts in transgenic tobacco. Transgenic Res. 4 60-69. 

Dowd P.F. Lagrimini L.M. (2006) Examination of the biological effects of high anionic peroxidases production in tobacco plants grown imder field conditions. 1. Insect pest damage. / / Transgenic Research. V. 15. P. 197-204. 

Yan J. Wang J. Tissue D. Holaday A. S. Allen R. Zhang H. (2003) Protection of photosynthesis and seed production under water-deficit conditions in transgenic tobacco plants that over-express Arabidopsis ascorbate peroxidase // Grop Sci. V. 43. P. 1477-483. 

Cell wall properties of transgenic tobacco plants that express a yeast derived acid invertase in their vacuole... 

At the moment, strategies for the production of transgenic plants are already used for maize, tobacco, potato, and rice. The main purpose is to increase their resistance toward diseases [63]. Some plants also get newly introduced products, such as vitamins [64]. Another purpose of transgenic plants is their use for production of vaccines for instance hepatitis B vaccine... 

Zhu, C., F. Kauder et al. (2007). Cloning of two individual cDNAS encoding 9-cw-epoxycarotenoid dioxygenase from Gentiana lutea, their tissue-specific expression and physiological effect in transgenic tobacco. J. Plant Physiol. 164(2) 195-204. 

The first hurdle encountered during the development of alfalfa as a recombinant protein production system was the relative inefficiency of the available expression cassettes. A study in which a tomato proteinase inhibitor I transgene was expressed in tobacco and alfalfa under the control of the cauliflower mosaic virus (CaMV) 35S promoter showed that 3-4 times more protein accumulated in tobacco leaves compared to alfalfa leaves [5]. Despite the low efficiency of the CaMV 35S promoter in alfalfa, bio-pharmaceutical production using this system has been reported in the scientific literature. Such reports include expression of the foot and mouth disease virus antigen [6], an enzyme to improve phosphorus utilization [7] and the anti-human IgG C5-1 [8]. In this last work, the C5-1 antibody accumulated to 1% total soluble protein [8]. 

Transgenic tobacco suspensions supplemented with a cocktail of essential and non-essential amino acids produced three-fold more IgG-2b/K antibody than untreated cultures [62]. The amino acids were added 10 h prior to harvesting of the cultures in the presence of 1 mM CaCl2 to facilitate amino acid uptake. 

As discussed above, Rubisco levels have been reduced by expressing antisense RNA in transgenic tobacco plants [26]. Plants expressing antisense rbcS RNA showed reduced levels of rbcS mRNA, normal levels of rbcL mRNA, and coordinately reduced levels of LSU and SSU proteins. 

Increased transcription levels are assumed to result in increased protein synthesis. One approach to reach this goal is to raise the transgene copy number by the use of amplification-promoting sequences derived from a spacer sequence of tobacco ribo-somal DNA [95]. Posttranscriptional processes such as capping, splicing and polya-denylation are important for high protein yields, and it is also important to maximize mRNA stability [84]. 

The most widely studied therapeutic proteins produced in plants include monoclonal antibodies for passive immunotherapy and antigens for use as oral vaccines [40]. Antibodies against dental caries, rheumatoid arthritis, cholera, E. coli diarrhea, malaria, certain cancers, Norwalk virus, HIV, rhinovirus, influenza, hepatitis B virus and herpes simplex virus have been produced in transgenic plants. However, the anti-Streptococcus mutans secretory antibody for the prevention of dental caries is the only plant-derived antibody currently in Phase II clinical trials [40]. Until recently, most antibodies were expressed in tobacco, potato, alfalfa, soybean, rice and wheat [9], It has been estimated that for every 170 tons of harvested tobacco, 100 tons represents harvested leaves. A single hectare could thus yield 50 kg of secretory IgA [3, 41]. Furthermore, it has been estimated that the cost of antibody production in plants is half that in transgenic animals and 20 times lower than in mammalian cell cul-... 

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