Multicellular living organisms and unmodified parts thereof and – Plant – seedling – plant seed – or plant part – per se
Reexamination Certificate
1999-04-26
2001-01-16
Schwartzman, Robert A. (Department: 1636)
Multicellular living organisms and unmodified parts thereof and
Plant, seedling, plant seed, or plant part, per se
C800S278000, C435S419000, C435S069100
Reexamination Certificate
active
06175060
ABSTRACT:
BACKGROUND OF THE INVENTION
Phosphorus is one of the most important nutrients for plants, being essential for their growth and a structural component of nucleic acids, phospholipids, intermediary metabolites and numerous other biological molecules. In plants, the only readily absorbed form of exogenous phosphorus is inorganic phosphate (P
i
) (Bieleski, 1973). When the amount of available phosphate is low, plants are unable to grow vigorously and productively. When phosphate is absent, growth is halted and the plant dies.
The phosphate to nitrogen ratio in plants affects both the temporal and quantitative characteristics of flowering (Salisbury and Ross, 1985). Relatively high phosphate advances maturity in plants, whereas relatively low phosphate results in little or no flowering taking place. Phosphate levels are also known to affect the biomass ratio between root and shoot. Specifically, phosphate deprivation causes preferential growth of roots (Lefebvre et al., 1982). Thus, in many environments, the availability of phosphorus becomes a major factor limiting the growth and reproduction of photosynthetic organisms.
Plants and other photosynthetic organisms are either sessile or restricted in movement and therefore limited in nutrient availability to their immediate environment. As a result, photosynthetic organisms require signal transduction pathways in order to trigger cellular responses to adverse environmental stimuli. As part of the adenosine nucleotides, ADP and ATP, which are the currency of cellular energy, phosphorus is critical to bioenergetics. The covalent addition or removal of a phosphate group to or from a biological substrate (phosphorylation and dephosphorylation, respectively) often functions as a kind of regulatory “on/off switch” in cellular metabolism and signal transduction. For example, the phosphorylation and dephosphorylation of certain membrane-bound receptor protein kinases and their substrates are key to various signal transduction pathways, including pathways of plant hormones such as ethylene (Kieber et al., 1993) and abscisic acid (Anderberg and Walker-Simmons, 1992). Self-incompatibility with respect to pollination and fertilization also involves the activity of protein kinases encoded by S-locus genes (Tantikanjana et al., 1993; Zhang and Walker, 1993). Regulatory signals can also trigger mechanisms for disease and pest control.
Although the nature of the phosphate-starvation response has been investigated in plants, little is known of the molecular mechanisms that regulate phosphorus uptake and metabolism. Few genes associated with phosphate-starvation expression in plants have been identified and isolated. To date, no reports of promoters which specifically respond to phosphate-starvation conditions are known.
Among the promoter sequences available for the genetic engineering of plants, depending upon the transcription initiation characteristics desired, (strength, tissue specificity, developmental specificity, etc.), different promoters can be employed to initiate transcription of a DNA sequence of interest joined at the 3′ end of the promoter region. For example, promoters such as the 35S Cauliflower Mosaic Virus (CaMV 35S), mannopine synthase (mas) and octopine synthase (ocs) have been used successfully to direct the expression of desired nucleic acid sequences in transformed plant tissue. When expressed in a transgenic plant, DNA sequences under the control of these promoters are found at relatively low or moderate levels and are expressed fairly evenly (i.e. constitutively) throughout the plant. See, for example, van der Zaal, et al. (1991)
Plant Mol. Biol.
16:983; Ohl, et al. (1990)
Cell
2:837.
Of particular interest, however, are promoters which demonstrate enhanced transcription initiation characteristics in rapidly dividing cells or rapidly growing tissue, against stress or other detrimental factors. Likewise, there are advantages with the increased expression of a DNA sequence of interest under the regulation of an inducible promoter. Such promoters regulate the expression of genes in response to environmental factors, such as light, wounding, exposure to heavy metals, low nutrient status, and/or temperature. However, isolated DNA elements responsive to environmental nutrients are rare.
The discovery of new promoters with useful transcript initiation patterns, especially ones having very strong promoter activity, are essential for the controlled expression of desirable nucleic acid sequences. Promoters which show enhanced activity induced by environmental phenomena are also of special interest for many genetic engineering tools to enhance plant characteristics generally, as these critical gene sequences are abundant in young or stressed plant tissue. Thus, a need exists for promoter sequences which can be used in recombinant DNA constructions to enable the external control of the expression of genes which can confer agronomic advantages when expressed at the proper time.
SUMMARY OF THE INVENTION
This invention provides a regulatory sequence useful for genetic engineering of plant cells to provide a method of controlling the timing or tissue pattern of expression of DNA sequences linked to this novel regulatory sequence.
This invention further relates to the 5′-flanking region (promoter) of a phosphate-starvation responsive &bgr;-glucosidase gene from
Arabidopsis thaliana
and to the regulatory-protein-binding sites within the 5′-flanking region of the phosphate-starvation responsive gene.
This invention also relates to manipulation of structure and the use of this promoter, or truncated sequences located within the promoter, to control, by the limitation of phosphate, the expression of genes in higher plants and other photosynthetic organisms.
The invention further provides a plant promoter that is capable of directing the expression of a gene of interest in specific tissues or throughout the body of a photosynthetic organism. In a preferred embodiment, the promoter is used to direct expression of a gene in a cell or tissue of a plant.
In another aspect of this invention, a transformation or an expression vector is provided comprising a promoter according to this invention. The promoter can be fused to a gene of interest and introduced into a photosynthetic organism, preferably a plant, to produce a product.
Further, this invention provides a transformed cell of a plant or another photosynthetic organism incorporating an isolated or recombinant promoter or functional fragment thereof in combination with a gene of interest of which the promoter directs expression.
Transgenic plants and other photosynthetic organisms are also provided which contain the constructs of this invention. In one embodiment, a transgenic plant is provided with a promoter according to this invention fused to a psr3.2 gene. Cultured cells and tissue derived from plants or other photosynthetic organisms which contain the nucleic acid constructs of this invention are also provided herein. This includes antisense constructs comprising the promoter of this invention linked to antisense nucleic acid which encodes a product expressed through the activity of an endogenous phosphate-deficient inducible promoter.
This invention further provides methods to alter the response of a cell, tissue, plant part or a plant or other photosynthetic organism to conditions under which phosphate is limiting. The promoter and methods of this invention can be used to selectively express structural genes in plants, especially in roots and shoots. The methods comprise growing a plant having integrated into its genome a regulatory region, or functional portion thereof, provided by this invention, operably linked to a structural gene.
This invention further provides a means for generally or specifically conferring resistance to pathogenic organisms or diseases in a plant which is most susceptible to such a pathogenic organism or disease under conditions of phosphate starvation. This use can result in the minimization or elimination of externally applied chemical t
Lefebvre Daniel D.
Malboobi Mohammad A.
Davis Katharine F
Hamilton Brook Smith & Reynolds P.C.
Performance Plants, Inc.
Schwartzman Robert A.
LandOfFree
Phosphate-deficiency inducible promoter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Phosphate-deficiency inducible promoter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phosphate-deficiency inducible promoter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2492220