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US5766900: Method of regenerating fertile transgenic Zea mays plants from protoplasts

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Filing Information

Inventor(s) Ray Shillito · Gleta Carswell · Christian Harms · Yin-Fu Chang ·
Assignee(s) Novartis Corporation ·
Attorney/Agent(s) Gary M. Pace ·
Primary Examiner Gary Benzion ·
Application Number US8418810
Filing date 04/07/1995
Issue date 06/16/1998
Predicted expiration date 05/20/2007
U.S. Classifications 435/172.3  · 435/172.1  ·
International Classifications C12N 1500  ·
Kind CodeA
International Classifications 435172.3;172.1;240.4;240.48;240.49 ·
Related U.S. Application DataThis application is a divisional of U.S. patent application Ser. No. 08/269,677, filed Jul. 1, 1994; which is a continuation of U.S. patent application Ser. No. 08/024,875, filed Mar. 1, 1993, which issued as U.S. Pat. No. 5,350,689 on Sep. 27, 1994, which is a continuation of U.S. patent application Ser. No. 07/276,210, filed Nov. 23, 1988, abandoned; which is a continuation-in-part of U.S. patent application Ser. No. 07/178,170, filed Apr. 6, 1988, abandoned; which is a continuation-in-part of U.S. patent application Ser. Nos. 07/056,552, filed May 29, 1987, abandoned, and Ser. No. 07/056,506, filed May 29, 1987, abandoned; of which Ser. No. 07/056,506 is a continuation-in-part of U.S. patent application Ser. No. 07/053,241, filed May 22, 1987, abandoned; which is a continuation-in-part of U.S. patent application Ser. No. 07/052,440, filed May 20, 1987, abandoned.
20 Claims, No Drawings


Abstract

Methods of regenerating fertile Zea mays plants from protoplasts or protoplast-derived cells are described. The protoplasts or cells may be derived from embryogenic cell cultures or callus cultures. The protoplasts, cells and resulting plants may be transgenic, containing, for example, chimeric genes coding for a polypeptide having substantially the insect toxicity properties of the crystal protein produced by Bacillus thuringiensis.

Independent Claims | See all claims (20)

  1. 1. A method for regenerating transgenic Zea mays plants from transgenic protoplasts comprising the steps of:(a) obtaining transgenic embryogenic Zea mays callus that is relatively nonmucilaginous, and is granular and friable, said callus being obtained by culturing an immature Zea mays embryo on a callus-inducing medium followed by the culture of said callus on a callus-maintaining medium,(b) transferring the callus to a liquid medium to form a suspension of cells or cell aggregates,(c) subculturing the suspension under conditions sufficient to maintain the cells and cell aggregates in a viable state,(d) selecting and retaining those cultures from the subcultured suspension of step (c) that contain aggregates of dense, cytoplasmic, dividing cells, sufficient to obtain, in a viable, dividing stage, Zea mays protoplasts capable of being regenerated into fertile plants,(e) removing the cell walls with suitable enzymes, and isolating Zea mays protoplasts,(f) plating the protoplasts in a suitable medium comprising a growth regulator selected from the group consisting of 2,4-D, dicamba, picloram and pCPA in which the protoplasts divide and form cells,(g) subculturing the cells resulting from step (f) in a suitable medium so as to multiply the cells,(h) further culturing the cells from step (g) in a suitable medium optionally comprising a cytokinin selected from the group consisting of kinetin, BAP, and zeatin,(i) further culturing the cells from step (h) in a suitable medium without growth regulators so as to regenerate Zea mays plantlets, and(j) culturing the Zea mays plantlets on a growing medium to obtain fertile plants, wherein the protoplasts contain stably incorporated exogenous DNA.
  2. 11. A method for regenerating transgenic Zea mays plants from protoplasts comprising the steps of:(a) obtaining embryogenic Zea mays callus that is relatively nonmucilaginous, and is granular and friable, said callus being obtained by culturing an immature Zea mays embryo on callus-inducing medium followed by the culture of said callus on a callus-maintaining medium,(b) transferring the callus to a liquid medium to form a suspension of cells or cell aggregates,(c) subculturing the suspension under conditions sufficient to maintain the cells and cell aggregates in a viable state,(d) selecting and retaining those cultures from the subcultured suspension of step (c) that contain aggregates of dense, cytoplasmic, dividing cells, sufficient to obtain, in a viable, dividing stage, Zea mays protoplasts capable of being regenerated into fertile plants,(e) removing the cell wall with suitable enzymes, isolating Zea mays protoplasts,(f) transforming said protoplasts with exogenous DNA by the method of electroporation or treatment with polyethylene glycol,(g) plating the protoplasts in a suitable medium comprising a growth regulator selected from the group consisting of 2,4-D, dicamba, picloram and pCPA in which the protoplasts divide and form cells,(h) subculturing the cells resulting from step (g) in a suitable medium so as to multiply the cells,(i) further culturing the cells from step (h) in a suitable medium optionally comprising a cytokinin selected from the group consisting of kinetin, BAP, and zeatin,(j) further culturing the cells from step (i) in a suitable medium without growth regulators so as to regenerate Zea mays plantlets, and(k) culturing the Zea mays plantlets on a growth medium to obtain fertile plants, wherein the protoplasts contain stably incorporated exogenous DNA.

References Cited

U.S. Patent Documents

Document NumberAssigneesInventorsIssue/Pub Date
US4448885 Board of the Regents of the University of Washington Schnepf et al. May 1984
US4467036 The Board of Regents of the University of Washington Schnepf et al. Aug 1984
US4665030 Sungene Technologies Corporation Close May 1987
US4666844 Sungene Technologies Corporation Cheng May 1987
US4684611 Rijksuniversiteit Leiden Schilperoort et al. Aug 1987
US4806483 Sungene Technologies Corporation Wang Feb 1989
US4820639 Massachusetts Institute of Technology Gehrke Apr 1989
US4830966 Sungene Technologies Corporation Close May 1989
US4999299 Ciba-Geigy Corporation Shillito et al. Mar 1991
US5049500 E. I. Du Pont de Nemours Arnizen et al. Sep 1991
US5120657 Agracetus, Inc. McCabe et al. Jun 1992
US5164310 The Texas A&M University System Smith et al. Nov 1992
US5177010 University of Toledo Goldman et al. Jan 1993
US5177308 Agracetus Barton et al. Jan 1993
US5187073 The University of Toledo Goldman et al. Feb 1993
US5231019 Ciba-Geigy Corporation Paszkowski et al. Jul 1993
US5254799 Plant Genetic Systems N.V. De Greve et al. Oct 1993
US5350689 Ciba-Geigy Corporation Shillito et al. Sep 1994
US5371003 Sandoz Ltd. Murry et al. Dec 1994
US5380831 Mycogen Plant Science, Inc. Adang et al. Jan 1995
US5384253 DeKalb Genetics Corporation Krzyzek et al. Jan 1995
US5484956 DeKalb Genetics Corporation Lundquist et al. Jan 1996
US5489520 DEKALB Genetics Corporation Adams et al. Feb 1996
US5500365 Monsanto Company Fischhoff et al. Mar 1996

Foreign Patent Documents

Document NumberAssigneesInventorsIssue/Pub Date
EP0086537RIJKSUNIVERSITEIT LEIDENAug 1983
EP0140556LUBRIZOL GENETICS INC.May 1985
EP0142924Mycogen Plant Science, Inc.May 1985
EP0160390STAUFFER CHEMICAL COMPANYNov 1985
EP0164575CIBA-GEIGY AGDec 1985
EP0174791MOLECULAR GENETICS RESEARCH & DEVELOPMENT LIMITEDMar 1986
EP0177738SUNGENE TECHNOLOGIES CORPORATIONApr 1986
EP0193259PLANT GENETIC SYSTEMS N.V.Sep 1986
EP0202739Mycogen CorporationNov 1986
EP0213818NOVO NORDISK A/SMar 1987
EP0223247CIBA-GEIGY AGMay 1987
EP0243533KAWASAKI JUKOGYO KABUSHIKI KAISHANov 1987
EP0257472Max-Planck-Gesellschaft zur FrderungMar 1988
EP0270356AGRACETUS, INC.Jun 1988
EP0292435CIBA-GEIGY AGNov 1988
EP0290395SANDOZ AGNov 1988
EP0465875Hoechst Schering AgrEvo GmbHJan 1992
EP0469273Bayer CropScience GmbHFeb 1992
EP0574356SANDOZ AGDec 1993
JP62239994OJI PAPER CO LTDOct 1987
JP63287485NORIN SUISANSYO NOGYO SEIBUTSU SHIGEN KENKYUSHONov 1988
GB2140822STAUFFER CHEMICAL CODec 1984
GB2183660CIBA GEIGY AGNov 1985
WO20WO8301176Apr 1983
WO20WO01856May 1985
WO20WO8504899Nov 1985
WO20WO8601536Mar 1986
WO20WO8603776Jul 1986
WO20WO8700551Jan 1987
WO20WO9102071Feb 1991

Other Publications

Green, C.E., "Somatic Embryogenesis and Plant Regeneration from the Friable Callus of Zea mays," Proc. 5th Intl. Cong. Plant Tissue and Cell Culture, pp. 107-108 (1982).
Green, C.E., and Rhodes, C.A., "Plant Regeneration in Tissue Cultures of Maize," in: Maize for Biological Research, University Press, University of North Dakota, Grand Forks, ND, pp. 367-372 (1982).
Harms, C.T., et al., "Regeneration of Plantlets from Callus Cultures of Zea mays L.," Z. Pflanzenzuchtg. 77:347-351 (1976).
Hauptmann, R.M., et al., "Transient Expression of Electroporated DNA in Monocotyledonous and Dicotyledonous Species," Plant Cell Reports 6:265-270 (Jul. 1987).
Hepher, A., et al., "Microinjection of DNA into Pollen, Ovaries and Somatic Cells," (Conference Paper), ILLUS ISBN 90-247-3131-3-32-33 (1985).
Hernalsteens, J.-P., et al., "An Agrobacterium-Transformed Cell Culture From the Monocot Asparagus officinalis,"EMBO J. 3(13):3039-3041 (1984).
Hodges, T.K., et al., "Genotype Specificity of Somatic Embryogenesis and Regeneration in Maize," Bio/Technology 4:219-223 (Mar. 1986).
Junker, B., et al., "Transient Expression of Chimaeric Genes in Dividing and Non-Dividing Cereal Protoplasts After PEG-Induced DNA Uptake," Plant Cell Reports 6:329-332 (Oct. 1987).
Kamo, K.K., et al., "Embryogenic Callus Formation From Maize Protoplasts," Planta 172:245-251 (Oct. 1987).
Kordyum, V.A., et al., "Transfer of dominant Allel of the Gene SU.sub.1 in Maize by Means of Exogenous DNA," Dopov. Akad. Nauk UKR. RSR Ser. B. Geol. Geofiz. Khim. Biol. 36(8):759-762 (1974).
Korohoda, J., and Strzalka, K., "High Efficiency Genetic Transformation in Maize Induced by Exogenous DNA," Z. Pflanzenphysiol. Bd. 94(S):95-99 (1979).
Lehman, P., and Nebiolo, C.M., "The Degree of Degradation of the Agrobacterium tumefaciens Ti Plasmid in Zea mays and Phaseolus vulgaris Protoplasts," Proc. Penn. Acad. Sci. 59(10):80 (1985).
Sheridan, W.F., "Tissue Culture of Maize. I. Callus Induction and Growth," Physiol. Plant 33:151-156 (1975).
Vasil, I.K., and Vasil, V., "Chapter 6. Regeneration in Cereal and Other Grass Species," in: Cell Culture and Somatic Cell Genetics of Plants, vol. 3: Plant Regeneration and Genetic Variability, I.K. Vasil, ed., Academic Press, Inc., Orlando, FL, pp. 121-150 (1986).
Welter, M.E., et al., "Morphotypes of Friable Embryogenic Maize Callus," Plant Cell Reports 14:725-729 (1995).
Werr, W., and Lorz, H., "Transient Gene Expression In a Gramineae Cell Line. A Rapid Procedure for Studying Plant Promoters," Mol. Gen. Genet. 202:471-475 (Mar. 1986).
English Abstract for Japanese Patent Document No. JP62-23994 (reference AM6), Derwent World Patent Index Accession No. 87-332762/47.
Expert Declaration of Steven V. Evola, Ph.D.
Fries, L. "Introduction of Plantlets in axenically cultivated rhizoids of Fucas spiralis," Can. J. Bot. 62(8):1616-1620, 1984.
Ammirato, P.V., "Chapter 3. Embryogenesis," in: Handbook of Plant Cell Culture. vol. 1, Techniques for Propagation and Breeding, Evans et al., eds., MacMillan Publishing Co., New York, pp. 82-123 (1983).
Bryant, J.A., "Transformation of Monocot Plants by the Ti Plasmid of Agrobacterium," Trends in Biotechnology 3(1):21 (1985).
Bytebier, B., et al., "T-DNA Organization in Tumor Cultures and Transgenic Plants of the Monocotyledon Asparagus officinalis," Proc. Natl. Acad. Sci USA. 84:5345-5349 (Aug. 1987).
Christou, P., et al., "Opine Synthesis in Wild-Type Plant Tissue," Plant Physiol. 82:218-221 (Sep. 1986).
de Wet, J.M.J., et al., "Gametophyte Transformation in Maize (Zea mays, Gramineae)," Illus ISBN 0-387-96267-0, pp. 59-64 (1986).
French, R., et al., "Bacterial Gene Inserted in an Engineered RNA Virus: Efficient Expression in Monocotyledonous Plant Cells," Science 231:1294-1297 (Mar. 1986).
Goodman, R.M., et al., "Gene Transfer in Crop Improvement," Science 236:48-54 (Apr. 1987).
Graves, A.C.F., and Goldman, S.L., "Agrobacterium tumefaciens-Mediated Transformation of the Monocot Genus Gladiolus: Detection of Expression of T-DNA-Encoded Genes," J. Bacteriol. 169(4):1745-1746 (Apr. 1987).
Armstrong et al., "Factors affecting PEG-mediated stable transformation of maize protoplasts", Plant Cell Reports 9:335-339 (1990).
Barton et al., "Bacillus thuringiensis .delta.-endotoxin expressed in transgenic Nicotiana tabacum provides resistance to lipidopteran insects", Plant Physiol. 85:1103-1109 (1987).
Bevan et al., "A chimaeric antibiotic resistance gene as a selectable marker for plant cell transformation", Nature 304:184-187 (Jul. 14, 1983).
Bevan, "Binary Agrobacterium vectors for plant transformation", Nucleic Acids Research 12(22):8711-8721 (1984).
Birk et al., "Separation of a tribolium-protease inhibitor from soybeans on a calcium phosphate column", Biochim. Biophys. Acta 67:326-328 (1963).
Brown, "The morphology of the grass embryo", Phytomorphology 10:215-223 (Oct. 1960).
Brown et al., "RFLP analysis of Zea mays callus cultures and their regenerated plants", Theor. Appl. Genet. 81:227-232 (1991).
Bruneau "In vitro regeneration from immature embryo callus in maize: quantitative aspects and transmission through crosses", Agronomie 5(7):591-596 (1985), Summary Only in English.
Callis et al., "Introns increase gene expression in cultured maize cells", Genes and Dev. 1:1183-1200 (1987).
Carswell et al., "O-acetyl-salicylic acid promotes colony formation from protoplasts of an elite maize inbred", Plant Cell Reports 8:282-284 (1989).
Chang, "Plant regeneration in vitro from leaf tissues derived from cultured immature embryos of Zea mays", Plant Cell Reports 2:183-185 (1983).
Chih-ching, "The N.sub.6 medium and its applications to another culture of cereal crops", Proc. Symp. on Plant Tissue Culture, Hulton (Ed.), Peking, pp. 43-50 (1978).
Chourey et al., "Callus formation from protoplasts of a maize cell culture", Theor. Appl. Genet. 59:341-344 (1981).
Covey et al., "Characterization of cauliflower mosaic virus DNA sequences which encode major polyadenylated transcripts", Nucleic Acids Research 9(24):6735-6747 (1981).
Dale, "Protoplast culture and plant regeneration of cereals and other recalcitrant crops", In: Lecture Proceedings, Experientia Supplementum 46, Potrykus et al. (Eds.), Birkhauser, Basel, pp. 31-41 (1983).
Datta et al., "Genetically engineered fertile indica-rice recovered from protoplasts", Bio/Technology 8:736-740 (1990).
Ding et al., "Identification of an effective vector constructed for maize transformation and study of PEG-mediated transformation method", Science in China (Series B) 35(10):1187-1195 (Oct. 1992).
Ditta et al., "Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti", Proc. Natl. Acad. Sci. USA 77(12):7347-7351 (Dec. 1980).
Duncan et al., "The production of callus capable of plant regeneration from immature embryos of numerous Zea mays genotypes", Planta 165:322-332 (1985).
Falco et al., "Nucleotide sequence of the yeast ILV2 gene which encodes acetolactate synthase", Nucleic Acids Research. 13 (11):4011-4027 (1985).
Feldmann and Marks, "Rapid and efficient regeneration of plants from explants of Arabidopsis thaliana", Plant Science 47:63-69 (1986).
Franck et al., "Nucleotide sequence of cauliflower mosaic virus DNA", Cell 21:285-294 (1980).
Fromm et al., "Expression of genes transferred into monocot and dicot plant cells by electroporation", Proc. Natl. Acad. Sci. USA 82:5824-5828 (1985).
Fromm et al., "Inheritance and expression of chimeric genes in the progeny of transgenic maize plants", Bio/Technology 8:833-839 (1990).
Fromm et al., "Stable transformation of maize after gene transfer by electroporation", Nature 319:791-793 (Feb. 27, 1986).
Gallie et al., "The 5'-leader sequence of tobacco mosaic virus RNA enhances the expression of foreign gene transcripts in vitro and in vivo", Nucleic Acids Research 15(8):3257-3273 (1987).
Geiser et al., "The hypervariable region in the genes coding for entomopathogenic crystal proteins of Bacillus thuringiensis: nucleotide sequence of the kurhd1 gene of subsp. kurstaki HD1", Gene 48:109-118 (1986).
Gordon-Kamm et al., "Transformation of maize cells and regeneration of fertile transgenic plants", The Plant Cell 2:603-618 (Jul. 1990).
Graves and Goldman, "The transformation of Zea mays seedlings with Agrobacterium tumefaciens", Plant Molecular Biology 7:43-50 (1986).
Green and Phillips, "Plant regeneration from tissue cultures of maize", Crop Sc. 15:417-421 (May-Jun. 1975).
Green, "Prospects for crop improvement in the field of cell culture", HortScience 12(2):131-134 (Apr. 1977).
Green and Armstrong, "Somatic cell genetic systems in corn", Advances in Gene Technology: Molec. Genet. of Plants and Animals, Downey et al. (Eds.), Academic Press, pp. 147-157 (1983).
Green et al., "Tissue Culture of Maize (Zea mays): Initiation, Maintainance, and Organic Growth Factors", Crop Science 14:54-58 (1974).
Gritz and Davies, "Plasmid-encoded hygromycin B resistance: the sequence of hygromycin B phosphotransferase gene and its expression in Escherichia coli and Saccharomyces cerevisiae", Gene 25:179-188 (1983).
Hammond et al., "Molecular cloning and analysis of a gene coding for the Bowman-Birk protease inhibitor in soybean", J. Biol. Chem. 259(15):9883-9890 (Aug. 10, 1984).
Harms and Potrykus, "Fractionation of plant protoplast types by iso-osmotic density gradient centrifugation", Theor. Appl. Genet. 53:57-63 (1978).
Hilder et al., "A novel mechanism of insect resistance engineered into tobacco", Nature 330:160-163 (Nov. 12, 1987).
Hohn et al., "Cauliflower mosaic virus on its way to becoming a useful plant vector", Current Topics in Microbiology and Immunology 96:193-236 (1982).
Hollingshead and Vapnek, "Nucleotide sequence analysis of a gene encoding a streptomycin/spectinomycin adenyltransferase", Plasmid 13:17-30 (1985).
Hood et al., "The hypervirulence of Agrobacterium tumefaciens A281 is encoded in a region of pTiBo542 outside of T-DNA", J. Bacteriol. 168(3):1291-1301 (Dec. 1986).
Hood et al., "Restriction endonuclease map of pTi Bo542, a potential Ti plasmid vector for genetic engineering of plants", Bio/Technology 2:702-709 (Aug. 1984).
Imbrie-Milligan and Hodges, "Microcallus growth from maize protoplasts prepared from embryogenic callus", Planta 168:395-401 (1986).
Imbrie-Milligan et al., "Microcallus growth from maize protoplasts", Chemical Abstracts 107:3682, Abstract No. 3685r (1987).
Jacoby et al., "Recombination between plasmids of incompatibility groups P-1 and P-2", J. Bacteriol. 127(3):1278-1285 (Sep. 1976).
Jayos-Rios, "Effects of different phytohormonal treatments on the organogenesis of callus tissues of Zea Mays", Annales des Sciences Naturelles, Botanique, Paris 13(7):55-62 (1985).
Jorgensen et al., "A restriction enzyme cleavage map of Tn5 and location of a region encoding neomycin resistance", Molec. Gen. Genet. 177:65-72 (1979).
Kamo and Hodges, "Establishment and characterization of long-term embryogenic maize callus and cell suspension cultures", Plant Science 45:111-117 (1986).
Kamo et al., "Regeneration of Zea mays L. from embryogenic callus", Botanical Gazette 146(3):327-334 (1985).
Kim et al., "Lodging Disease, and Insect Resistant, and High Yielding Maize Hybrid `Suweon 21`", Res. Rep. of Rual Dev. (Suweon) 20 (Crop), pp. 163-168 (1979) (Abstract in English).
Klausner, "Microbial insect control using bugs to kill bugs", Bio/Technology 2:409-419 (May 1984).
Kreis et al., "Structure and evolution of seed storage proteins and their genes with particular reference to those of wheat, barley and rye", Oxford Surveys of Plant Molecular & Cell Biology 2:253-317 (1985).
Krens et al., "In vitro transformation of plant protoplasts with Ti-plasmid DNA", Nature 296:73-74 (Mar. 4, 1982).
Lee et al., "Isolation, culture and morphogenesis from wheat protoplasts, and study of expression of DNA constructs by direct gene transfer", Plant Cell, Tissue and Organ Culture 12:223-226 (1988).
Lipke et al., "Effect of soybean inhibitors on growth of Tribolium confusum", Agricultural and Food Chemistry 2:410-414 (1954).
Lloyd et al., "Transformation of Arabidopsis thaliana with Agrobacterium tumefaciens", Science 234:464-466 (Oct. 24, 1980).
Lorz et al., "Gene transfer to cereal cells mediated by protoplast transformation", Mol. Gen. Genet. 199:178-182 (1985).
Lowe et al., "Plant regeneration via organogenesis and embryogenesis in the maize inbred line B73", Plant Science 41:125-132 (1985).
Lu et al., "Isolation and Culture of Protoplasts of Panicum maximum Jacq. (Guinea Grass): Somatic Embryogenesis and Plantlet Formation," Z. Phlanzenphys. Bd. 104:311-318 (1981).
Lu et al., "Improved efficiency of somatic embryogenesis and plant regeneration in tissue cultures of maize (Zea mays)", Theor. Appl. Genet. 66:285-289 (1983).
Lu et al., "Somatic embryogenesis in Zea mays", Theor. Appl. Genet. 62:109-112 (1982).
Ludwig et al., "High frequency callus formation from maize protoplasts", Theor. Appl. Genet. 71:344-350 (1985).
Lurquin, "Transfer of plasmid DNA to plant protoplasts. I. Conditions mimicking virus or viral nucleic acid infection", Archives Interationales de Physiologie et de Biochemie 87(4):824-825 (1979).
Lyznik et al., "Stable co-transformation of maize protoplasts with gusA and neo genes", Plant Molecular Biology 13:151-161 (1989).
Lyznik et al., "Stable transformation of maize: the impact of feeder cells on protoplast growth and transformation efficiency", Plant Cell Reports 8:292-295 (1989).
Mackey et al., "Transgenic Maize", in: Transgenic Plants, Academic Press, vol. 2:21-33 (1993).
Matzke and Chilton, "Site-specific insertion of genes into T-DNA of the Agrobacterium tumor-inducing plasmid: an approach to genetic engineering of higher plant cells", J. Appl. Genet. 1:39-49 (1981).
Miller et al., "Bacterial, viral, and fungal insecticides", Science 219:715-721 (Feb. 11, 1983).
Mitchell and Petolino, "Haploid suspension and protoplast culture from isolated microspores of maize", Progress in Plant Cellular and Molec. Biol., Proceedings of the VIIth Intl. Cong. on Plant Tissue and Cell Culture, Nijkamp et al. eds., Kluwer Academic Publ., pp. 264-269 (1990).
Morelli et al., "A short conserved sequence is involved in the ligh-inducibility of a gene encoding ribulose 1,5-bisphosphate carboxylase small subunit of pea", Nature 315:200-204 (May 16, 1985).
Morocz et al., "Plant regeneration from haploid and diploid Zea mays protoplast cultures", Abstracts VIIth International Congress on Plant Tissue and Cell Culture, Amsterdam, Abstract No. A1-102, Jun. 24-29, 1990.
Morocz et al., "An improved system to obtain fertile regenerants via maize protoplasts isolated from a highly embryogenic suspension culture", Theor. Appl. Genet. 80:721-726 (1990).
Negrutiu et al., "Hybrid genes in the analysis of transformation conditions", Plant Mol. Biology 8:363-373 (1987).
Ohta, "High-efficiency genetic transformation of maize by a mixture of pollen and exogenous DNA", Proc. Natl. Acad. Sci. USA 83:715-719 (Feb. 1986).
Omirulleh et al., "Activity of chimeric promoter with the doubled CaMV 35S enhancer element in protoplast-derived cells and transgenic plants in maize", Plant Molecular Biology 21:415-428 (1993).
Oka et al., "Nucleotide sequence at the insertion sites of a kanamycin transposon", Nature 276:845-847 (Dec. 21/28, 1978).
Oka et al., "Nucleotide sequence of the kanamycin resistance transposon Tn9O3", J. Mol. Biol. 147:217-226 (1981).
Pareddy and Petolino, "Somatic embryogenesis and plant regeneration from immature inflorescences of several elite inbreds of maize", Plant Science 67:211-219 (1990).
Paszkowski et al., "Direct gene transfer to plants", EMBO Journal 3(12):2217-2722 (1984).
Payne et al., "Isolation of the genomic clone for pathogenesis-related protein a from Nicotiana tabacum cv. Xanthi-nc", Plant Molecular Biology 11:89-94 (1988).
Petersen et al., "Effect of nurse cultures on the production of macro-calli and fertile plants from maize embryogenic suspension culture protoplasts", Plant Cell Reports 10:591-594 (1992).
Polaina, "Cloning of the ILV2, ILV3 and ILV5 genes of Saccharomyces cerevisiae", Carlsberg Res. Commun. 49:577-584 (1984).
Potrykus et al., "Callus formation from stem protoplasts of corn (Zea mays)", Mol. Gen. Genet. 156:347-350 (1977).
Potrykus et al., "Callus formation from cell culture protoplasts of corn (Zea mays)", Theor. Appl. Genet. 54:209-214 (1979).
Potrykus et al., "Problems in culturing cereal protoplasts", Cell Genetics in Higher Plants, Proceedings of an International Training Course, Dudits et al. (Eds.), Szeged, Hungary, pp. 129-140 (Jul. 5-17, 1976).
Potrykus et al., "Direct gene transfer to cells of a graminaceous monocot", Mol. Gen. Genet. 199:183-188 (1985).
Potrykus I., "Gene transfer to plants: Assessment of published approaches and results", Annu. Rev. Plant Physiol. Plant Mol. Biol. 42:205-225 (1991).
Prioli and Sondahl, "Plant regeneration and recovery of fertile plants from protoplasts of maize (Zea mays)," Bio/Technology 7:589-594 (Jun. 1989).
Radojevic, "Tissue culture of maize Zea mays <<Cudu>>. I. Somatic embryogenesis in the callus tissue", J. Plant Physiol. 119:435-441 (1985).
Randolf, "Developmental morphology of the caryopsis in maize", J. Agric. Research 53(12):881-916 (Dec. 15, 1936).
Rapela, "Organogenesis and somatic embryogenesis in tissue cultures of Argentine maize (Zea mays)", J. Plant Physiol. 121:119-122 (1985).
Rhodes et al., "Factors affecting tissue culture initiation from maize tassels", Plant Sci. 46:225-232 (1986).
Rhodes et al., "Genetically transformed maize plants from protoplasts", Science 240:204-207 (1988).
Rhodes et al., "Plant regeneration from protoplasts isolated from embryogenic maize cell cultures", Bio/Technology 6:56-60 (1988).
Rothstein et al., "Promoter cassettes, antibiotic-resistance genes, and vectors for plant transformation", Gene 53:153-161 (1987).
Ryan, "Proteolytic enzymes and their inhibitors in plants", Ann. Rev. Plant Physiol. 24:173-196 (1973).
Sanchez de Jimenez et al., "Effect of 2,4-D analogues on the induction and maintenance of callus in maize tissue culture", Ann. Appl. Biol. 98:347-353 (1981).
Sanford et al., "Attempted pollen-mediated plant transformation employing genomic donor DNA", Theor. Appl. Genet. 69:571-574 (1985).
Saxena and Rashid, "Differentiation of bud-cells on the protonema of the moss Anoectangium thomsonii. Effect of aspirin and salicylic acid", Z. Pflanzenphysiol. Bd. 99:187-189 (1980).
Saxena and Rashid, "Development of gametophores from isolated protoplasts of the moss Anoectangium thomsonii Mitt.", Protoplasma 103:401-406 (1980).
Schenk and Hildebrandt, "Medium and techniques for induction and growth of monocotyledonous and dicotyledonous plant cell cultures", Canadian Journal of Botany 50:199-204 (1972).
Sciaky et al., "Fingerprints of Agrobacterium Ti plasmids", Plasmid 1:238-253 (1978).
Sekar et al., "Molecular cloning and characterization of the insecticidal crystal protein gene of Bacillus thuringiensis var. tenebrionis", Proc. Natl. Acad. Sci. USA 84:7036-7040 (Oct. 1987).
Shaw and Kamen, "A conserved AU sequence from the 3' untranslated region of GM-CSF mRNA mediates selective mRNA degradation", Cell 46:659-667 (Aug. 29, 1986).
Sheikholeslam and Weeks, "Acetosyringone promotes high efficiency transformation of Arabidopsis thaliana explants by Agrobacterium tumefaciens", Plant Molec. Biol. 8:291-298 (1987).
Shillito et al., "Regeneration of fertile plants from protoplasts of elite inbred maize", Bio/Technology 7:581-587 (Jun. 1989).
Shillito et al., "High efficiency direct gene transfer to plants", Bio/Technology 3:1099-1103 (Dec. 1985).
Shinshi et al., "Regulation of a plant pathogenesis-related enzyme: inhibition of chitinase and chitinase mRNA accumulation in cultured tobacco tissues by auxin and cytokinin", Proc. Natl. Acad. Sci. USA 84:89-93 (1987).
Shneyour et al., "A simple feeder-layer technique for the plating of plant cells and protoplasts at low density", Plant Science Lett. 33:293-302 (1984).
Sleat et al., "Studies on the mechanism of translational enhancement by the 5'-leader sequence of tobacco mosaic virus RNA", Eur. J. Biochem. 175:75-86 (1988).
Smith et al., "Feeder layer support of low density populations of Zea mays L. suspension cells", Plant Science Lett. 36:67-72 (1984).
Sun et al., "Regeneration of haploid and dihaploid plants from protoplasts of supersweet (sh2sh2) corn", Plant Cell Reports 8:313-316 (1989).
Suprasanna et al., "Plantlet regeneration from glume calli of maize (Zea mays)", Theor. Appl. Genet. 72:120-122 (1986).
Thompson et al., "Characterization of the herbicide-resistance gene bar from Streptomyces hygroscopicus", EMBO Journal 6:2519-2523 (1987).
Tomes and Smith, "The effect of parental genotype on initiation of embryogenic callus from elite maize (Zea mays) germplasm", Theor. Appl. Genet. 70:505-509 (1985).
Torne and Santos, "Aspects of totipotency in calli cultures of Zea mays: maintenance and variability of totipotent structures", Inv. Agrar.: Prod. Prot. Veg. 2(2):111-120 (1987).
Torne et al., "Methods of obtaining maize totipotent tissues. II. Atrophic tissue culture", Plant Science Letters 33:317-325 (1984).
Treissman, "Transient accumulation of c-fos RNA following serum stimulation requires a conserved 5' element and c-fos 3' sequences", Cell 42:889-902 (Oct. 1985).
Vaeck et al., "Transgenic plants protected from insect attack", Nature 328:33-37 (Jul. 2, 1987).
Vasil et al., "Plant Regeneration from Protoplasts of Napier Grass (Pennisetum purpureum Schum.)", Z. Pflanzenphys. Bd. 111:233-239 (1983).
Vasil et al., "Proliferation and plant regeneration from the nodal region of Zea mays (maize, gramineae) embryos", Amer. J. Bot. 70(6):951-954 (1983).
Vasil, V. and Vasil, I.K., "Formation of callus and somatic embryos from protoplasts of a commercial hybrid of maize (Zea mays)", Theor. Appl. Genet. 73:793-798 (1987).
Vasil, V. and Vasil, I.K., "Isolation and culture of cereal protoplasts", Theor. Appl. Genet. 56:97-99 (1980).
Vasil, V. and Vasil, I.K., "Plant regeneration from friable embryogenic callus and cell suspension cultures of Zea mays", J. Plant Physiol. 124:399-408.
Wang, "Callus induction and plant regeneration from maize mature embryos", Plant Cell Reports 6:360-362 (1987).
Wong et al., "Transcriptional and translational start sites for the Bacillus thuringiensis crystal protein gene", J. Biol. Chem. 258(3):1960-1967 (Feb. 10, 1983).
Wullems et al., "The expression of tumour markers in intraspecific somatic hybrids of normal and crown gall cells from Nicotiana tabacum", Theor. App. Genet. 56:203-208 (1980).
Yadov et al., "Short direct repeats flank the T-DNA on a nopaline Ti plasmid", Proc. Natl. Acad. Sci. USA 79:6322-6326 (Oct. 1982).
Yamada and Sakaguchi, "Polyethylene glycol-induced uptake of bacteria into yeast protoplasts", Agricultural and Biological Chemistry 45(10):2301-2309 (1981).
Zoller and Smith, "Oligonucleotide-directed mutagenesis: a simple method using two oligonucleotide primers and a single-stranded DNA template", DNA 3(6):479-488 (1984).

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