Patent ID: 6284956
Filing Date: 2001-09-04
Classification: C12N,C12Y

Abstract:
A method of transforming rice plants with one or more heterologous nucleic acid coding sequences capable of producing heterologous proteins in the rice, under selected induction conditions, comprisingcotransforming rice callus cells with a set of two or more expression cassettes, said set comprising:(a) a chimeric selectable marker expression cassette having, operatively linked in sequence in a 5' to 3' direction, (i) a transcriptional regulatory region which expresses in transformed callus cells at a significantly higher level than in seed tissue, and hybridizes under high stringency conditions with the rice .beta.-glucanase gene (Gns9) promoter identified by SEQ ID NO:1; (ii) a hygromycin phosphotransferase encoding gene and (iii) a 3' untranslated terminator region; and(b) at least one heterologous gene expression cassette, having operatively linked in sequence in a 5' to 3' direction, (i) a transcriptional regulatory region that is expressed, induced or inducible in plant seeds, (ii) a first DNA sequence encoding a selected heterologous protein, and (iii) a 3' untranslated terminator region, wherein the transcriptional regulatory region in said heterologous-gene expression cassette is induced during seed maturation or seed germination;culturing the callus cells in the presence of a selection agent effective to block growth of callus cells in the absence of expression of the hygromycin phosphotransferase encoding gene;selecting those callus cells that express hygromycin phosphotransferase, as evidenced by their growth in the presence of the selection agent; andregenerating the selected callus cells into transgenic plants under non-selection conditions.