Tobacco BY-2 cells as effective bioreactor for the production of puroindolines

Puroindolines are two small proteins so called for the presence of an hydrophobic tryptophan-rich domain. Associated to wheat starch granules in Triticum aestivum, puroindolines have been shown to be responsible for the softness of the wheat endosperm. Moreover, have been proved to possess bactericide and anti-fungal properties together with the capacity of forming very stable foams. All these features make puroindolines very attractive for medical, pharmaceutical and food industrial applications. The aim of this study was to explore a plant molecular farming approach for producing a recombinant puroindolines. Three specific recombinant constructs, aimed for the expression in the apoplast and chloroplast compartments, were prepared and used for transformation of Nicotiana tabacum cv BY-2 cells. Recombinant PINB targeted to the chloroplast was obtained as 0.35% of BY-2 cell TSP. Antimicrobial activity experiments demonstrated that at MIC concentration recombinant PINB is responsible for about 91% growth inhibition of E. coli.