Expression of correctly processed human growth hormone in seeds of transgenic tobacco plants

Human growth hormone was expressed in transgenic tobacco seeds using the monocot tissue-specific promoter from sorghum γ-kafirin seed storage protein gene. During tobacco seed ripening, the expressed hormone was directed to the endoplasmic reticulum by a signal peptide from a Coix prolamin and was secreted into the apoplastic space, where it accounted for 0.16% of total soluble seed protein. The expressed hormone has the same amino acid sequence and receptor-binding properties as the native mature hormone.