title: New findings in potential applications of tobacco osmotin.
abstract: The osmotin protein is involved in both monocot and dicot plant responses to biotic and abiotic stress. To determine the biological activity of osmotin, the gene was amplified from tobacco genomic DNA, fused with the hexahistidine tag motif and successfully expressed in Escherichia coli, after which the recombinant osmotin was purified and renatured. Various activities were then tested, including hemolytic activity, toxicity against human embryonic kidney cells, and the antifungal activity of the recombinant osmotin. We found that osmotin had no adverse effects on human kidney cells up to a concentration of 500 μg.ml-1. However, the purified osmotin also had significant antimicrobial activity, specifically against fungal pathogens causing candidiasis and otitis, and against the common food pathogens. Using the osmotin-Agrobacterium construct, the osmotin gene was inserted into tobacco plants in order to facilitate the isolation of recombinant protein. Using qPCR, the presence and copy number of the transgene was detected in the tobacco plant DNA. The transgene was also quantified using mRNA, and results indicated a strong expression profile, however the native protein has been never isolated. Once the transgene presence was confirmed, the transgenic tobacco plants were grown in high saline concentrations and monitored for seed germination and chlorophyll content as indicators of overall plant health. Results indicated that the transgenic tobacco plants had a higher tolerance for osmotic stress. These results indicate that the osmotin gene has the potential to increase crop tolerance to stresses such as fungal attack and unfavorable osmotic conditions.
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Viktorova
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Katerina
authors.initials: K
authors.lastname: Rehorova
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Musilova
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Jachym
authors.initials: J
authors.lastname: Suman
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Lovecka
authors.affiliation: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28, Prague 6, Czech Republic. Electronic address: macekt@vscht.cz.
authors.forename: Tomas
authors.initials: T
authors.lastname: Macek
mesh_terms: D006801:Humans; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D010940:Plant Proteins; C073139:osmotin protein, Nicotiana tabacum
keywords: Agrobacterium; Antifungal activity; Osmotin; Stress; Tobacco; Toxicity