Abstract: An artificial promoter system that can be fused upstream of any desired gene enabling reversible induction or repression of the expression of the gene at will in any suitable host cell or organisms by light is described. The design of the system is such that a molecule of the plant photoreceptor phytochrome is targeted to the specific DNA binding site in the promoter by a protein domain that is fused to the phytochrome and that specifically recognizes this binding site. This bound phytochrome, upon activation by light, recruits a second fusion protein consisting of a protein that binds to phytochrome only upon light activation and a transcriptional activation domain that activates expression of the gene downstream of the promoter.

Abstract: An artificial promoter system that can be fused upstream of any desired gene enabling reversible induction or repression of the expression of the gene at will in any suitable host cell or organisms by light is described. The design of the system is such that a molecule of the plant photoreceptor phytochrome is targeted to the specific DNA binding site in the promoter by a protein domain that is fused to the phytochrome and that specifically recognizes this binding site. This bound phytochrome, upon activation by light, recruits a second fusion protein consisting of a protein that binds to phytochrome only upon light activation and a transcriptional activation domain that activates expression of the gene downstream of the promoter.

Abstract: The present invention is directed to nucleic acid sequences encoding a novel regulatory element that induces a high level of expression to operably linked genes, upon exposure to hypoxic conditions. Furthermore, the regulatory element can be used to prepare an expression vector for transforming plant cells, wherein the DNA construct comprises a hypoxia inducible promoter operably linked to a gene sequence.

Abstract: The present invention is directed to recombinant expression vectors comprising a suicide gene flanked by site-specific recombination sequences and the use of those expression vectors to produce trangenic plants that facilitating the production of hybrid plants. The transgenic plants produced in accordance with the present invention comprise a novel male-sterility/restorer system, wherein a male sterile plant is cross-fertilized with a restorer plant to produce a hybrid plant.