Expression of the Escherichia coli heat-labile enterotoxin B subunit in transgenic watercress (Nasturtium officinale L.)

• Published in: Plant cell, tissue and organ culture Vol. 105; no. 1; pp. 39 - 45
• Main Authors: Loc, Nguyen Hoang, Van Song, Nguyen, Tien, Nguyen Quang Duc, Minh, Tang Thuy, Nga, Phan Thi Quynh, Kim, Tae-Geum, Yang, Moon-Sik
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.04.2011; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Assembly; Bacteria; Biological activity; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Cell surface; Deoxyribonucleic acid; DNA; E coli; Endoplasmic reticulum; Enterotoxin B; Enzyme-linked immunosorbent assay; Escherichia coli; Fundamental and applied biological sciences. Psychology; Gene expression; Genetic transformation; Heat-labile enterotoxin; Life Sciences; Nasturtium officinale; Original Paper; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Plant tissues; Proteins; Rorippa nasturtium-aquaticum; Synthesis; Transgenic plants; Watercress; Edible vaccine; Enterotoxigenic; Synthetic gene; Watercress; heat-labile enterotoxin B subunit (LTB); Codon optimization; Escherichia coli; Subunit; Optimization; Codon; Gene; Cruciferae; Dicotyledones; Angiospermae; Edibility; Bacteria; Transgenesis; Enterobacteriaceae; Vegetals; Vaccine; Toxin; Heat; Enterotoxigenic Escherichia coli heat-labile enterotoxin B subunit (LTB); Enterotoxin; Instability; Spermatophyta; Nasturtium officinale; Genetically modified organism
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-010-9835-0

A gene encoding the B subunit of the enterotoxigenic Escherichia coli heat-labile enterotoxin (LTB) was adapted to the optimized plant coding sequence, and fused to the endoplasmic reticulum retention signal SEKDEL in order to enhance its expression level and protein assembly in plants. The synthetic LTB (sLTB) gene was placed into a plant expression vector under the control of the CaMV 35S promoter, and subsequently introduced into the watercress (Nasturtium officinale L.) plant by the Agrobacterium-mediated transformation method. The integration of the sLTB gene into the genomic DNA of transgenic plants was confirmed by genomic DNA PCR amplification. The assembly of plant-produced LTB protein was detected by western blot analysis. The highest amount of LTB protein produced in transgenic watercress leaf tissue was approximately 1.3% of the total soluble plant protein. GM₁-ganglioside enzyme-linked immunosorbent assay indicated that plant-synthesized LTB protein bound specifically to GM₁-ganglioside, which is the receptor for biologically active LTB on the cell surface, suggesting that the plant-synthesized LTB subunits formed biologically active pentamers.