The United States of America As Represented by the Secretary of

Delta and Pine Land Company

United States of America, As Represented by the Secretary of Agriculture

D&pl Technology Holding Company, LLC

Melvin John Oliver

Don Lee Keim

Norma Lee Trolinder

Jerry Edwin Quisenberry

John J Burke

Jeffrey P Velten

Patrick J O'Mahony

Transgenic cells may be selected using temperature sensitive marker proteins. In this method, a population of host cells are transformed with a foreign DNA construct which includes at least one first nucleic acid coding sequence and a second nucleic acid sequence encoding a temperature sensitive marker protein, wherein each of the first and second nucleic acid coding sequences are operatively linked to gene expression control sequences. Suitable temperature sensitive marker proteins which may be used herein include heat shock proteins, heat shock transcription factors, cold regulated proteins (COR), or cold regulated protein transcription factors. Following transformation, the population of cells are cultured under temperature conditions wherein growth of non-transformed cells is suppressed or prevented while growth of cells transformed with the DNA construct is supported or promoted. Thus, survival and/or significant growth of a cell is an indication that the cell has been successfully transformed with the DNA construct. Those cells are considered presumptively positive transformants, and may be recovered.

Selection procedure for identifying transgenic cells, embryos, and plants without the use of antibiotics

A method for making a genetically modified plant comprising regenerating a whole plant from a plant cell that has been transfected with DNA sequences comprising a first gene whose expression results in an altered plant phenotype linked to a transiently active promoter, the gene and promoter being separated by a blocking sequence flanked on either side by specific excision sequences, a second gene that encodes a recombinase specific for the specific excision sequences linked to a repressible promoter, and a third gene that encodes the repressor specific for the repressible promoter. Also a method for making a genetically modified hybrid plant by hybridizing a first plant regenerated from a plant cell that has been transfected with DNA sequences comprising a first gene whose expression results in an altered plant phenotype linked to a transiently active promoter, the gene and promoter being separated by a blocking sequence flanked on either side by specific excision sequences to a second plant regenerated from a second plant cell that has been transfected with DNA sequences comprising a second gene that encodes a recombinase specific for the specific excision sequences linked to a promoter that is active during seed germination, and growing a hybrid plant from the hybrid seed. Plant cells, plant tissues, plant seed and whole plants containing the above DNA sequences are also claimed.

Control of plant gene expression

A medium is disclosed that supports pollen germination and pollen tube growth in the presence of Agrobacterium, the medium comprising agarose, sucrose, NO.sub.3, MnSO.sub.4, H.sub.3 BO.sub.3, MgSO.sub.4 and gibberellic acid. A method is disclosed for the genetic transformation of plants and lines by a pollen-based Agrobacterium-mediated transformation. The method comprises the steps of obtaining pollen from a first plant, applying a lawn of Agrobacteria to a solid pollen culture medium, the Agrobacterium comprising at least one heterologous gene sequence capable of being transferred to a plant cell, applying the pollen to the solid medium, allowing the pollen to germinate and grow on the medium, whereby the Agrobacterium attaches to the pollen tube or mediates transfer of the heterologous gene sequence to the germinating pollen to obtain transgenic pollen, applying the transgenic pollen to the stigma of a second plant capable of being fertilized by the pollen of the first plant, thereby fertilizing the second plant, obtaining transgenic seed from the second plant and germinating the transgenic seed to obtain a transgenic plant. The method is particularly suited for use with so-called 'dry stigma' pollen.

Pollen-based transformation system using solid media

Growing community of inventors

Lubbock, TX, United States of America

Melvin John Oliver