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: A DNA segment from the upstream untranscribed region of a maize ubiquitin gene is disclosed. This ubiquitin promoter region, which comprises heat shock consensus elements, initiates and regulates the transcription of genes placed under its control. Recombinant DNA molecules are also described in which a ubiquitin promoter is combined with a plant expressible structural gene for regulated expression of the structral gene and for regulated control of expression when stressed with clevated temperatures. Such recombinant DNA molecules are introduced into plant tissue so that the promoter/stuctural gene combination is expressed.

Abstract: A method of inducibly enhancing the constitutive expression of a DNA sequence of interest is described in which plant cells are transformed with a DNA sequence of interest that is operably joined to a plant ubiquitin regulatory region comprised of a heat shock element, a promoter, a transcription start site, an intron and a translation start site, When monocot or dicot plant cells are subjected to permissive heat shock temperatures, the level of expression of the DNA sequence of interest is enhanced.

Abstract: A dark- and light-regulated chlorophyll a/b (Cab) binding protein promoter/regulatory system from maize is disclosed. This promoter/regulatory system is capable of accounting for as much as 80% of the total Cab mRNA in the dark and results in enhancement of expression from 3- to 6-fold after conditions of illumination. This Cab promoter/regulatory system may be recombined with structural genes for expression in plant cells.

Abstract: A plant chlorophyll a/b binding (Cab) protein gene was isolated from a maize genomic library. The promoter/regulatory system of this gene actively functions in controlling Cab gene expression under conditions of darkness and in enhancing gene expression under conditions of light. This invention contemplates the utilization of the Cab promoter/regulatory system in regulating non-homologous structural gene expression in transgenic plants under conditions of darkness followed by further enhancement of gene expression under conditions of light.

Abstract: A method of inducibly enhancing the constitutive expression of a DNA sequence of interest is described in which plant cells are transformed with a DNA sequence of interest that is operably joined to a plant ubiquitin regulatory region comprised of a heat shock element, a promoter, a transcription start site, an intron, and a translation start site. When monocot or dicot plant cells are subjected to permissive heat shock temperatures, the level of expression of the DNA sequence of interest is enhanced.

Abstract: A DNA segment from the upstream untranscribed region of a maize ubiquitin gene is disclosed. This ubiquitin promoter region, which comprises heat shock consensus elements, initiates and regulates the transcription of genes placed under its control. Recombinant DNA molecules are also described in which a ubiquitin promoter is combined with a plant expressible structural gene for regulated expression of the structural gene and for regulated control of expression when stressed with elevated temperatures. Such recombinant DNA molecules are introduced into plant tissue so that the promoter/structural gene combination is expressed.