Use of the wound-inducible NtQPT2 promoter from Nicotiana tabacum for production of a plant-made vaccine

Abstract

The wound-inducible quinolinate phosphoribosyl transferase promoter from Nicotiana tabacum (NtQPT2) was assessed for its capacity to produce B-subunit of the heat-labile toxin (LTB) from enterotoxigenic Escherichia coli in transgenic plant tissues. Comparisons were made with the widely used and constitutive Cauliflower Mosaic Virus 35S (CaMV35S) promoter. The NtQPT2 promoter produced somewhat lower average concentrations of LTB protein per unit weight of hairy root tissue but allowed better growth thereby producing similar or higher overall average yields of LTB per culture batch. Transgenic tobacco plants containing the NtQPT2-LTB construct contained LTB protein in roots but not leaves. Moreover, wounding NtQPT2-LTB transgenic plants, by removal of apices, resulted in an approximate 500% increase in LTB levels in roots when analysed several days later. CaMV35S-LTB transgenic plants contained LTB protein in leaves and roots but wounding made no difference to their LTB content.

Cloning and functional characterization of quinolinic acid phosphoribosyl transferase (QPT) gene of Nicotiana tabacum

“…On the contrary, Li et al () described the QPT2 gene to be involved in the nicotine biosynthetic pathway. The activity and expression of QPT gene has been well characterized (Sinclair et al , Guzman et al ).…”

“…Antisense‐mediated suppression of QPT1 gene was shown to be an effective means of decreasing alkaloid production, nicotine in particular, in Nicotiana species (Xie et al , Ziegler, ). However, it is not known what aspects of plant morphophysiology may be affected by QPT through its links with key enzymes associated with nicotine production such as the ornithine decarboxylase ( ODC ), MPO , putrescine methyltransferase ( PMT ) and A622 (Rongvaux et al , Katoh et al , Matsui et al , Guzman et al , Ryan et al ).…”