Constitutive cauliflower mosaic virus

As indicated in Table 2.1, most of the promoters used in plant tissue culture have been based on the constitutive cauliflower mosaic virus (CaMV) 35S promoter. In contrast, inducible promoters have the advantage of allowing foreign proteins to be expressed at a time that is most conducive to protein accumulation and stability. Although a considerable number of inducible promoters has been developed and used in plant culture applications, e.g. [32-37], the only one to be applied thus far for the production of biopharmaceutical proteins is the rice a-amylase promoter. This promoter controls the production of an a-amylase isozyme that is one of the most abundant proteins secreted from cultured rice cells after sucrose starvation. The rice a-amylase promoter has been used for expression of hGM-CSF [10], aranti-trypsin [12, 29, 38, 39] and human lysozyme [30]. 

To test the hypothesis that phosphate supply from the can limit the rate of photosynthesis (Sivak and Walker, 1986), antisense experiments were performed by Schultz et al. (1993). A cDNA for the potato triose phosphate translocator was identified and a fragment of this cDNA in reverse orientation was expressed in trangenic potato plants under the control of the constitutive cauliflower mosaic virus 35S promoter (Rismeier et al., 1993). This experiment confirmed that Pi supply can limit photosynthesis since a... 

Schoffi, F., Rieping, M. Baumann, G. (1987). Constitutive transcription of a soybean heat-shock gene by a cauliflower mosaic virus promoter in transgenic tobacco plants. Developmental Genetics 8,365-74. 

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