Generation of fungal laccase producing transgenic tobacco plants using a root-specific expression promoter

Laccases are a group of glycoproteins which can oxidize a wide range of compounds with various biological activities and industrial applications in food and beverage, pharmaceutical, textile, and even military-related industries. Regarding this enzyme structure and the ability of plant protein production machinery for protein glycosylation, a construct consisting of fungal laccaseII under control of root-specific mannopine synthase promoter and tobacco etch virus translation enhancer was designed for tobacco transformation to be used in phytoremediation. N-terminal addition of acidic tobacco endochitinase Q to Laccase directs its apoplastic secretion. Putative laccase agrobacterium-mediated transformants were confirmed using polymerase chain reaction. Semi-quantitative PCR of roots and leaves of putative transformants showed differential expression of the laccase gene at the transcriptomic level resulting from the differential function of bacterial mannopine synthase promoter. Western blotting results confirmed production of mature protein in roots which also confirms the correct function of signal peptide and secretion of this enzyme into the apoplastic space of roots. Regarding their application for protein production or phytoremediation transgenics of interest should be screened based on protein concentration and enzyme activity.