Facile method for identifying regulated promoters

Abstract

A new method for the identification of useful promoters is disclosed. The method is capable of identifying bacterial promoters sensitive to a particular cellular insult and may be modified to identify promoters sensitive to herbicides and crop protection chemicals. Constructs comprising promoters upstream of a luminescent reporter genes are placed in transformed hosts. Transformants grown in liquid media to a predetermined growth stage and contacted with a cellular insult are assessed for regulatory region activity by measurement of the resulting change in bioluminescence. The method is able to identify promoters undetectable by standard methods.

Description

FIELD OF INVENTION

The invention relates to the discovery and characterization of regulated promoters aided by use of reporter gene fusions. More specifically the invention creates gene fusion comprising bioluminescent reporter genes in transformed hosts grown in liquid media to identify regulated promoters.

BACKGROUND OF THE INVENTION

Technological advances within the chemical arts supporting the agrochemical, pharmaceutical and environmental industries have made possible the synthesis of vast arrays of chemical compounds. The utility of these compounds is modeled on various structure-function relationships. Compound utility of often confirmed through screening methods designed to associate these compounds with desired known activities. Currently, methods of synthesis are capable of producing far more compounds than can be reasonably screened. A need exists for the development of rapid high-throughput screens that are able to analyze vast numbers of compounds for putative agrochemical, environmental, or pharmaceutical activities.

Current screening methods are often costly, time intensive, and lacking in specificity where the screens must rely on studies in whole plants and animals. A variety of methods have been developed using engineered microorganisms to detect and characterize compound activity. One such test is the Ames test (McCann et al. Mutat. Res. (1984), 134(1), 1-47) where Salmonella sp. are used to characterize compounds as mutagenic or pro-mutagenic. The Ames test relies on the unique enzymatic properties of S. typhimurium to characterize xenobiotics as mutagens or pro-mutagens. Other microorganism-based systems for the characterization of compounds have relied on the specificity of gene promoters or regulatory regions to identify potential compound activity. For example, Orser et al. ( In Vitro Toxicol. (1995), 8(1):71-85) utilizes a stress promoter fused to a promoterless lacZ structural gene to screen compounds for environmental toxicity, Molders et al. (WO 9008836) teaches the use of recombinant bacteria to detect the presence of mercury using a gene complex consisting of a mer regulatory region that is hypersensitive to induction by mercury and Burlage et al. ( J. Bacteriol, 172 (9):4749-4757 (1990)) recites a method using a naphthalene sensitive regulatory region from plasmid NAH7 to detect naphthalene-like compounds.

Microbiological methods such as these hold great promise for the screening of compounds for specific activities; however they are impeded by the lack of a facile reporting system and by the difficulty in identifying regulatory regions specific for the activities to be screened for. A rapid method for the identification of new, compound sensitive regulatory regions combined with a facile reporting gene would represent a significance advance in the art of compound screens. Genes responsible for bacterial bioluminescence are gaining increasing interest as facile reporters and offer a partial solution to the development of rapid high-throughput screens for new compound activities.

Bioluminescent bacteria are found in marine and terrestrial environments. The lux gene products from marine organisms often exhibit thermolability such that they do not function well at typical growth temperatures for other bacteria (Szittner and Meighen, J. Biol. Chem., 265:16581-16587 (1990); Rupani et al., Biotechnol Prog, 12:387-392 (1996); Hill et al., Biotechnol Appl Biochem, 17:3-14 (1993)). In contrast, the lux gene products from the terrestrial microorganism Photorhabdus luminescens (formerly called Xenorhabdus luminescens ) are stable at temperatures up to 45° C. (Szittner and Meighen, J. Biol. Chem., 265:16581-16587 (1990)). Therefore, the advantage of the thermostable lux genes is that a larger range of assay temperatures are available for use.

Recent advances in recombinant DNA technology have made it possible to express the luciferase (lux) gene complex as heterologous gene products. This is generally accomplished by placing the lux structural gene complex under the control of a host promoter. So, for example, cDNA encoding firefly luciferase has been expressed in E. coli under the control of the lacZ promoter. (Tatsumi et al., Biochem. Biophys Acta., 1131, 2:161-165, (1992)), and the luxAB fusion gene has been expressed in Bacillus at levels comparable to those achievable in E. coli by placing it under the control of the powerful Pxyn promoter (Jacobs et al., Mol. Gen. Genet., 230(1-2):251-256, (1991)).

Stress genes are found in all cells and are defined as those genes activated as a result of any type of insults that might alter the normal cellular metabolism. Environmental insults often induce synthesis of an overlapping set of proteins. The most well recognized class of stress genes are the heat shock genes encoding a set of cellular proteins thought to have roles in refolding, recycling and resynthesis of proteins. The heat shock phenomenon was first described as a response to an increased temperature. Subsequent work has shown that exposure to a variety of insults including phage infection, macrophage envelopment, as well as the presence of organic molecules and heavy metals can also trigger the heat shock response. The common theme of the inducing agents may be unfolding of some proteins within the cell. (LaRossa et al., Mol. Micriobiol., 5(3):529-523, (1991)). Thus the response may integrate and report a wide range of environmental insults. VanBogelen et al., ( J. Bacteriol., 169(1):26-32, (1987)) have demonstrated that a variety of chemicals are able to induce the heat shock genes in E. coli , including CdCl 2 , H 2 O 2 , ethanol, puromycin and nalidixic acid. Blom et al., ( Appl. Environ. Microbiol., 58(1):331-334, (1992)) teach that the exposure of E. coli cultures to benzene, CdCl 2 , chlorpyrivos, 2,4-dichloraniline, dioctylphtalate, hexachlorobenzene, pentachlorophenol, trichlorethylene, and tetrapropylbenzosulfonate leads to the induction of up to 39 different stress proteins, as analyzed by two dimensional gel electrophoresis. LaRossa et al. (PCT International Application WO 94/13831) have transformed E. coli with a construct comprised of luxCDABE operably linked to a variety of stress promoters. They have used the microorganisms to detect a variety of environmental insults such as ethanol, CdCl 2 , and toluene. The presence of a sublethal concentration of the insult is indicated by an increase in bioluminescence. The detector organism described in WO 94/13831 was also used in a lyophilized form to detect similar environmental stresses by an increase in bioluminescence (Van Dyk, T. and Wagner, W., International Application No. PCT/US 95/15224.

Since the cell attempts to maintain a steady state, stress responses are activated well below the minimal inhibitory concentration for any condition that serves as a triggering factor. It would be useful to identify complete sets of promoters induced by any particular stress.

Thus, genes responsible for bacterial bioluminescence offer a partial solution to the need for a microorganism-based screening method for compound activity. Still needed, however, is a rapid method for the identification of useful regulatory regions.

Various methods of screening for bacterial promoter activity and for regulatory regions affected by various conditions are known. It is very common to use reporter genes for such a task. For example, transposons which can be inserted throughout the genome can be engineered to have reporter genes that require an external promoter sequence to be expressed and hence activity of the reporter gene is indicative of transcription initiated at the upstream chromosomal promoter sequences. A classic example of this approach is the work of Kenyon and Walker in discovering genes induced by DNA damage (Kenyon and Walker, Proc. Natl. Acad. Sci. U.S.A., 77:2819-2823 (1980)). Many such transposons are available and have been recently reviewed (Berg and Berg, Transposable element tools for microbial genetics, in Escherichia coli and Salmonella Cellular and Molecular Biology , p.2588-2612, F. C. Neidhardt, Editor. 1996, ASM Press: Washington, D.C.). Alternatively, plasmids with reporter genes lacking promoter activity have also been used to discover promoters, such as the vectors described by Simons et al., Gene, 53:85-96 (1987)). These plasmids have a multiple cloning site (MCS) upstream of the lacZYA operon that lacks its normal promoter. Just upstream of the MCS were placed multiple transcription terminators so that transcription initiated at other places on the plasmid would terminate prior to the lacZ reporter gene.

One of the reporters of transcriptional activity frequency used in transposons and plasmids are the bacterial lux genes (Engebrecht et al., Science, 227:1345-1347 (1985)). The lux reporter is distinct because the reporter gene products' activity, light production, can be measured without disruptin the cell. Furthermore, if the five gene luxCDABE reporter system is used, continuous monitoring of light production is possible without adding substrate exogenously. However, previous use of lux reporters for discovery of promoters have not taken advantage of such continuous monitoring and have, in general, qualitatively estimated promoter activity by the light production on petri plates (Carmi, O. A., et al., J. Bacteriol., 169:2165-2170 (1987); Guzzo and DuBow, Arch. Microbial., 156:444-448 (1991); Guzzo et al., Appl. Environ. Microbiol., 57:2255-2259 (1991); Guzzo and DuBow, Mol. Gen. Genet., 242:455-460 (1994); Kragelund et al., FEMS Microbiol. Ecol., 17:95-106 (1995); Waterfield et al., Gene, 165:9-15 (1995)).

These previously used methods of screening for lux reporter activity on petri plates have been limited by being restricted to growth conditions and averaged stages of growth of bacterial cells within colonies on solidified medium. It was also not possibly to apply a stress condition and quickly visualize changes in gene expression.

The problem to be overcome, therefore is a method for the identification of gene regulatory regions, responsive to a particular cellular stress, such as that produced by herbicides or crop protection chemicals. Applicants have solved the stated problem by randomly fusing regulatory regions to a bacterial luminescent gene complex where contacting the fusion in a suitable host with a cellular insult producing a cellular stress results in detection of that cellular stress by an increase in cellular luminescence. Applicants methods of screening in liquid medium has the additional advantage of being able to detect regulatory regions that cannot be discovered by current methods, which are restricted to screening on the basis of colony formation on solid medium. The versatility of being able to screen for stress or chemical responsive regulatory regions rapidly and in a growth phase of the investigators choice represents a clear advance in the art.

SUMMARY OF THE INVENTION

Applicants have provided a method for identifying regulatory regions modulated by a cellular insult in a specific gene pool having the steps:

(i) creating a library of gene fusions to a luminescent reporter gene complex in suitable bacteria to create fusion-containing strains;

(ii) culturing individual gene fusion-containing strains in liquid media;

(iii) contacting the fusion-containing strains at a particular growth phase with a cellular insult for which the fusion-containing strain is known to be sensitive; and

(iv) analyzing the fusion-containing strain for a change in luminescence relative to a baseline luminescence, said change in luminescence indicating that the regulatory region is modulated by the cellular insult.

In particular, the method permits recovering the fusion-containing strains containing a regulatory region modulated by the cellular insult.

The method uses a luminescent reporter gene complex selected from the group consisting of a bacterial lux gene complex, a gene complex encoding luciferase from Renella species, and a luc gene complex, and more particularly, a thermostable lux gene complex or a lux CDABE gene complex.

The method can be used with any cellular insult, more particularly, with a crop protection chemical such as sulfometuron methyl (SM), one member of the class of N-(heterocyclicaminocarbonyl)sulfonamide-containing herbicidal chemical compounds.

Particular embodiments of the invention include 1) an E. coli 1.9 kb genomic segment containing an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO: 1 and SEQ ID NO: 2; 2) an E. coli 1.4 kb genomic segment containing an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO: 15 and SEQ ID NO: 16; 3) an E. coli 1.8 kb genomic segment containing an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO: 11 and SEQ ID NO: 12; and 4) an E. coli 1.6 kb genomic segment containing an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO: 19 and SEQ ID NO: 20.

The invention also encompasses plasmids containing:

(i) an E. coli genomic segment containing an SM-responsive regulatory region operably linked to a thermostable luxCDABE gene complex; and

(ii) a transcription terminator region upstream of said promoter.

The particular plasmids have an E. coli genomic segment bounded by unique pairs of DNA fragments selected from the group consisting of SEQ ID NOS: 1 and 2, SEQ ID NOS: 3 and 4, SEQ ID NOS: 5 and 6, SEQ ID NOS: 7 and 8, SEQ ID NOS: 9 and 10, SEQ ID NOS: 11 and 12, SEQ ID NOS: 13 and 14, SEQ ID NOS: 15 and 16, SEQ ID NOS: 17 and 18, SEQ ID NOS: 19 and 20, SEQ ID NOS: 21 and 22, SEQ ID NOS: 23 and 24, and SEQ ID NOS: 25 and 26.

The invention also encompasses transformants comprising a suitable host cell and the disclosed plasmid wherein the transformant is sensitive to SM.

The suitable host cell used in the transformant is a bacteria classified in the Family Enterobacteriaceae, and particularly preferred is Escherichia coli.

A further embodiment of the invention is a method to detect chemical compounds potentially useful as a crop protection chemical having the steps:

(i) contacting the chemical compound with a detector organism containing a genomic segment comprising a responsive regulatory region operably linked to a luminescent reporter gene complex;

(ii) measuring an increase in bioluminescence in the detector organism, the increase in bioluminescent indicating that the chemical compound is potentially useful as a crop protection chemical.

The genomic segments useful in the invention are selected from the group consisting of a) an E. coli 1.9 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 1 and SEQ ID NO: 2; b) an E. coli 1.4 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 3 and SEQ ID NO: 4; c) an E. coli 1.9 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 5 and SEQ ID NO: 6; d) an E. coli 1.3 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 7 and SEQ ID NO: 8; e) an E. coli 2.5 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 9 and SEQ ID NO: 10; f) an E. coli 1.8 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 11 and SEQ ID NO: 12; g) an E. coli 1.2 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 13 and SEQ ID NO: 14; h) an E. coli 1.4 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 15 and SEQ ID NO: 16; i) an E. coli 1.3 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 17 and SEQ ID NO: 18; j) an E. coli 1.6 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 19 and SEQ ID NO: 20; k) an E. coli 1.9 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 21 and SEQ ID NO: 22; l) an E. coli 1.0 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 23 and SEQ ID NO: 24; and m) an E. coli 2.0 kb genomic segment containing an SM-responsive regulatory region, said segment bounded by SEQ ID NO: 25 and SEQ ID NO: 26.

Gene fusions useful in the invention include those a) comprising the SM-responsive regulatory region contained within the E. coli 1.9 kb genomic segment of claim 13 , the SM-responsive regulatory region operably linked to a luminescent reporter gene complex; b) comprising the SM responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 3 and SEQ ID NO: 4, the regulatory region operably linked to a luminescent reporter gene complex; c) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 5 and SEQ ID NO: 6, the regulatory region operably linked to a luminescent reporter gene complex; d) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 7 and SEQ ID NO: 8, said regulatory region operably linked to a luminescent reporter gene complex; e) comprising the SM responsive regulatory region contains within the genomic segment bounded by SEQ ID NO: 9 and SEQ ID NO: 10, the regulatory region operably linked to a luminescent reporter gene complex; f) comprising the SM-responsive regulatory region contained within the E. coli 1.8 kb genomic segment of claim 15 , the regulatory region operably linked to a luminescent reporter gene complex; g) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 13 and SEQ ID NO: 14, said regulatory region operably linked to a luminescent reporter gene complex; h) comprising the SM-responsive regulatory region contained within the E. coli 1.4 kb genomic segment of claim 14 , the regulatory region operably linked to a luminescent reporter gene complex; i) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 17 and SEQ ID NO: 18, the regulatory region operably linked to a luminescent reporter gene complex; j) comprising the SM-responsive regulatory region contained within the E. coli 1.7 kb genomic segment of claim 16 , the regulation region operably linked to a luminescent reporter gene complex; k) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 21 and SEQ ID NO: 22the regulatory region operably linked to a luminescent reporter gene complex; l) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 23 and SEQ ID NO: 24, the regulatory region operably linked to a luminescent reporter gene complex; and m) comprising the SM-responsive regulatory region contained within the genomic segment bounded by SEQ ID NO: 25 and SEQ ID NO: 26, the regulatory region operably linked to a luminescent reporter gene complex.

BRIEF DESCRIPTION OF DRAWINGS, BIOLOGICAL DEPOSITS, AND SEQUENCE LISTING

The file of this patent contains at least one drawing executed in color. Copies of this patent with color drawing will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.

FIG. 1 shows the restriction sites and genes of plasmid pDEW201, a promoter probe vector.

FIGS. 2 and 3 show graphically light production as a function of insert size for individual transformants of Library A and Library B, respectively.

FIG. 4 shows graphically the induction of bioluminescence of transformant DPD2088 by sulfometuron methyl.

FIG. 5 shows graphically patterns of bioluminescence induction in transformants DPD3509, DPD2087, and DPD2081 by various herbicidal compounds.

FIG. 6 is a color-enhanced, electronic image of an X-ray film comparing bioluminescence of transformants DPD2084, DPD2081, DPD2088, DPD3512, and DPD2092 that were cultured on plates with and without sulfometuron methyl induction.

Applicants have made the following biological deposits under the terms of the Budapest Treaty of the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure:

Depositor Identification	Int‘l. Depository
Reference	Designation	Date of Deposit
Escherichia coli DPD2083	ATCC 98227	Oct. 16, 1996
(host strain DPD1675
containing plasmid PDEW201)

“ATCC” refers to the American Type Culture Collection international depository located at 6801 University Blvd., Manassas, Va. 20110-2209, U.S.A. The designations refer to the accession number of the deposited material.

Applicants have provided 28 sequences in conformity with Rules for the Standard Representation of Nucleotide and Amino Acid Sequences in Patent Applications (Annexes I and II to the Decision of the President of the EPO, published in Supplement No. 2 to OJ EPO, 12/1992), and with 37 C.F.R. 1.821-1.825 and Appendices A and B (Requirements for Application Disclosures Containing Nucleotides and/or Amino Acid Sequences).

DETAILED DESCRIPTION OF THE INVENTION

Applicants have solved the significant problem of how to identify regulatory regions affected by cellular stress such as that created to crop protection chemicals in cells growing in a specified growth phase in a liquid medium. The solution involves analyzing luminescence and changes in luminescence following stress of cells grown to a specified growth phase in liquid medium. Using this method, promoters encompassing >1000-fold range of activity were readily found, which is far greater than the range of promoter activities found by previously used methods. For example, Waterfield et al (Waterfield, et al., Gene, 165:9-15 (1995)) using standard colony formation methods found promoters in Lactococcus lactis encompassing only a 71-fold range of activity. Furthermore, several genetic fusions to previously uncharacterized or known genes of E. coli were found by this method. Thus the instant method is able to detect promoters or stress responsive regulatory regions undetectable by current methods.

Utility Statement

The present invention provides a method of discovery and characterization of promoter regions using probe vectors that use a bioluminescent reporter gene complex. Isolated chromosomal DNA is digested with a restriction enzyme to give overlapping fragments, which are subsequently ligated upstream of the reporter genes. Those DNA sequences containing promoters will result in transcription and subsequent translation of the reporter gene products and hence light production from cells containing the fusion plasmid. Quantitation of this bioluminescence results in identification of sequences with promoter activity.

The following definitions are used herein and should be referred to for claim interpretation.

The term “bioluminescence” refers to the phenomenon of light emission from any living organism.

The term “baseline bioluminescence” refers to light emission of a microorganism in the absence of stress.

The term “lux” refers to the lux structural gene which include luxA, luxB, luxC, luxD and luxE and which are responsible for the phenomenon of bacterial bioluminescence. A lux gene complex might include all of the independent lux genes, acting in concert, or any subset of the lux structural genes so long as luxA and luxB are part of the complex.

The term “stress” or “cellular stres” refers to the condition produced in a cell as the result of exposure to a cellular insult. A “cellular insult” may be any substance or change in the cellular environment that results in an alteration of normal cellular metabolism in a bacterial cell or population of cells. Such cellular insults may include, but are not limited to, chemicals (such as herbicides, crop protection chemicals, environmental pollutants, heavy metals), physical treatments such as changes in temperature, changes in pH, agents producing oxidative damage or DNA damage (such as from UV exposure), anaerobiosis, biological insults such as the introduction of other life forms (viruses, bacteria, etc.) into the bacterial culture, or changes in nutrient availability.

A “luminescent reporter gene complex” means any reporter gene or genes the products of which result in light production, such as the bacterial lux genes, the firefly (for example, Photinus pyralis ), or click beetle (for example, Pyrophorus plagiophthalamus ) luciferase genes (luc), or the gene encoding the luciferase for the sea pansy, Renilla reniformis.

“Host cell sensitivity” is a characteristic of a bacterial strain such that its metabolic activity is inhibited by addition of a chemical compound, biological entity, or physical treatment.

The term “multiple cloning site” (MCS) refers to a genetic element in which multiple sites of restriction endonuclease cleavage are embedded.

The terms “promoter” and “promoter region” refer to a sequence of DNA, usually upstream of (5′ to) the protein coding sequence of a structural gene, which controls the expression of the coding region by providing the recognition for RNA polymerase and/or other factors required for transcription to start at the correct site. Promoter sequences are necessary but not always sufficient to drive the expression of the gene. In this method, promoters are defined by their ability to result in expression of the reporter gene complex when cloned upstream of the reporter genes. Furthermore, activation of the promoter by a stress is defined as an increase of activity of the reporter gene complex following application of the stress.

A “fragment” constitutes a fraction of the DNA sequence of the particular region.

“Gene fusion” is a hybrid DNA fragment comprising a regulatory signal essential for transcription (referred to as a promoter) fused to at least one structural gene sequence coding for a specific polypeptide.

The term “genomic segment” refers to a DNA fragment containing a gene regulatory region. Genomic segments of the present invention are typically derived from the E. coli genome and contain regulatory regions responsive to a variety of cellular insults including those produced by contact with crop protection chemicals and herbicides.

The term “regulatory region” refers to a DNA fragment containing any of the genetic elements responsible for directing gene transcription and translation, including promoter or initiation control regions, coding regions, open reading frames (ORF) and transcriptional termination regions. Regulatory regions may be positively activated by a variety of stimuli resulting in up-regulation of genes and an increase in transcription. “Regulation” and “regulate” refer to the modulation of gene expression controlled by DNA sequence elements located primarily, but not exclusively upstream of (5′ to) the transcription start of a gene. Regulation may result in an all-or-none response to a stimulation, or it may result in variations in the level of gene expression. In the context of the present invention, regulatory regions activated by or responsive to sulfometuron methyl (“SM-responsive”) were identified. For a review of regulation of bacterial genes see Escherichia coli and Salmonella Cellular and Molecular Biology , (1225-1309), F. C. Neidhardt, Editor. 1996, ASM Press: Washington, D.C.).

The term “coding sequence” refers to that portion of a gene encoding a protein, polypeptide, or a portion thereof, and usually excluding the regulatory sequences which drive the initiation of transcription. A coding sequence may be one normally found in the cell or it may be one not normally found in a cellular location, but one that is instead introduced, in which case it is termed a heterologous gene. The coding sequence may be a composite of fragments derived from different sources, naturally occurring or synthetic.

The term “operably linked” refers to the fusion of two fragments of DNA in a proper orientation to be transcribed into functional RNA.

The term “expression” refers to the transcription and translation to gene product from a gene coding for the sequence of the gene product. In the expression, a DNA chain coding for the sequence of gene product is first transcribed to a complimentary RNA which is often a messenger RNA and, then, the thus transcribed messenger RNA is translated into the above-mentioned gene product if the gene product is a protein.

The term “plasmid” or “vector” as used herein refers to an extra chromosomal element often carrying genes which are not part of the central metabolism of the cell, and usually in the form of circular double-stranded DNA molecules. Such elements may be autonomously replicating sequences, genome integrating sequences, phage or nucleotide sequences, linear or circular, of a single- or double-stranded DNA or RNA, derived from any source, in which a number of nucleotide sequences have been joined or recombined into a unique construction which is capable of introducing a promoter fragment and DNA sequence for a selected gene product along with appropriate 3′ untranslated sequence into a cell. Plasmid pDEW201 has the unique features of carrying the Photorhabdus luminescens luxCDABE genes without a promoter, upstream of which are transcription terminator sequences and a MCS. The derivatives of pDEW201 described herein contain E. coli chromosomal DNA cloned into the MCS.

The term “restriction endonuclease” or “restriction enzyme” refers to an enzyme which binds and cuts within a specific nucleotide sequence within double-stranded DNA.

“Liquid media” refers to microbial growth medium that is not solidified, such as by addition of agar.

“Growth phase” refers to stages of bacterial cell growth of the cells in liquid medium which allows for a uniform population of cells to be produced. Examples of growth phases include such as early log phase, mid log phase, late log phase or stationary phase.

The term “log phase” or “log phase growth” refers to cell cultures of detector organisms growing under conditions permitting the exponential multiplication of the detector cell number.

The term “Relative Light Unit” is abbreviated “RLU” and refers to a measure of light emission as measured by a luminometer, calibrated against an internal standard unique to the luminometer being used.

The term “crop protection chemical” or “CPC” refers to compounds having toxic or repellent effect on insects, plant pathogens, or crop-completing plant species known to damage crop plants. CPC includes pesticides (paraquat, copper sulfate, metidathion), anti-pathogenic compounds such as fungicides (chlorothalonil) or responsible for insect behavior modulation (pheromones, allomones and kairomones), and herbicides referring to compounds having specific or general toxicity to plant species. Typical herbicides include but are not limited to the class of sulfonylurea herbicides and sulfonanilide herbicides (chlorsulfuron, triasulfuron, metsulfuron-methyl), auxin herbicides (e.g. dicamba, 2-methyl-4-chlorophenoxyacetic acid, picloram, quinclorac, quinmerac), pre-emergence herbicideds (metribuzin), and post-emergence herbicides (Clethodim Pendimethalin, oryzalin, dithiopyr, oxadiazon, prodiamine, 2-4-D).

“Sulfonylurea herbicides” are defined as N-(heterocyclicaminocarbonyl)-arylsulfonamide-containing herbicidal compounds that inhibit the enzyme acetolactate synthase, such as sulfometuron methyl.

The term “sulfometuron methyl” refers to 2-[[[[(4,6-dimethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoic acid, methyl ester (CAS registry number 74222-97-2), and is abbreviated as “SM”.

The term “sulfometuron methyl inducible promoter” is a promoter that is activated by the presence of sulfometuron methyl.

The term “detector organism” refers to an organism which contains a gene fusion consisting of a promoter fused to a structural gene and which is capable of expressing the lux gene products in response to cellular stress. Typical detector organisms include but are not limited to bacteria.

“Enteric bacteria” are members of the family Enterobacteriaceae, and include such members as Escherichia, Salmonella, and Shigella. They are gram-negative straight rods, 0.3-1.0×1.0-6.0 μm, motile by peritrichous flagella, except for Tatumella, or nonmotile. They grow in the presence and absence of oxygen and grow well on peptone, meat extract, and (usually) MacConkey's media. Some grown on D-glucose as the sole source of carbon, whereas others require vitamins and/or mineral(s). They are chemoorganotrophic with respiratory and fermentative metabolism but are not halophilic. Acid and often visible gas is produced during fermentation of D-glucose, other carbohydrates, and polyhydroxyl alcohols. They are oxidase negative and, with the exception of Shigella dysenteriae 0 group 1 and Xenorhabdus nematophilus , catalase positive. Nitrate is reduced to nitrite except by some strains of Erwinia and Yersina. The G+C content of DNA is 38-60 mol % (T m , Bd). DNAs from species from species within most genera are at least 20% related to one another and to Escherichia coli , the type species of the family. Notable exceptions are species of Yersina, Proteus, Providenica, Hafnia and Edwardsiella, whose DNAs are 10-20% related to those of species from other genera. Except for Erwinia chrysanthemi all species tested contain the enterobacterial common antigen (Bergy's Manual of Systematic Bacteriology, D. H. Bergy, et al., Baltimore: Williams and Wilkins, 1984).

The term “transformation” refers to the stable acquisition of new genes in a cell following incorporation of nucleic acid.

“Transformant” refers to the strain that results from transformation.

Reporter genes

The preferred reporter gene for the present invention is the lux gene complex, responsible for bacterial bioluminescence and isolated from the bacteria Photorhabdus luminescens . Bacterial bioluminescence is the phenomenon in which the products of 5 structural genes (luxA, luxB, luxC, luxD and luxE) work in concert to produce light. The luxD product generates a C 14 fatty acid from a precursor. The C 14 fatty acid is activated in an ATP dependent reaction to an acyl-enzyme conjugate through the action of the luxE product which couples bacterial bioluminescence to the cellular energetic state. The acyl-enzyme (luxE product) serves as a transfer agent, donating the acyl group to the luxC product. The acyl-LuxC binary complex is then reduced in a reaction in which NADPH serves as an electron pair and proton donor reducing the acyl conjugate to the C 14 aldehyde. This reaction couples the reducing power of the cell to bacterial light emission. The light production reaction, catalyzed by luciferase (the product of luxA and luxB), generates light. The energy for light emission is provided by the aldehyde to fatty acid conversion and FMNH 2 oxidation, providing another couple between light production and the cellular energy state.

The source of the bacteria lux complex was the pJT205 plasmid (formerly called pCGLS205) containing the Photorhabdus luminescens luxCDABE gene complex, fully described by (Rosson, R. A., PCT International Application WO 93/03179 (1993)).

Other reporter genes or gene complexes could also be used. Examples include but are not limited to the lux genes from marine microorganisms such as Vibrio fischeri, Vibrio harveyi , or Photobacterium phosphoreum , or the genes encoding luciferases from insects such as Photinus pyralis or Pyrophorus plagiophthalamus or the sea pansy, Renilla reniformis.

Vectors

The invention provides a transformation vector containing a lux gene fusion, capable of transforming a bacterial host cell for the expression of the Lux proteins. A variety of transformation vectors may be used, however, those capable of transforming E. coli are preferred. pDEW201 is a specific example of a suitable transformation vector whose construction is given in detail in the following text. This vector represents only a sample of the total number of vectors created for the purpose of introducing promoter-lux reporter fusions into host cells. However, it will be readily apparent to one of skill in the art of molecular biology that the methods and materials used in their construction are representative of all other vectors described.

Transformation vectors such as these are common and construction of a suitable vector may be accomplished by means well known in the art. The preferred source of the lux genes is a pre-existing plasmid containing a promoterless lux gene complex.

Methods of creating gene fusions

The present invention provides a method for creating gene fusions where a gene regulatory region (typically comprising a promoter) is responsive to some cellular stress, is fused to a luminescent reporter gene complex. Fusions of the present invention may be created by a variety of methods in including partial restriction digests of genomic DNA, PCR, LCR or strand displacement amplification of known regions of the genome or by in vitro transposition.

Restriction Digests

The preferred method of generating gene fusions is isolation of chromosomal DNA from a bacterial species, partial digestion of that chromosomal DNA yielding overlapping fragments with a restriction enzyme such that compatible sticky ends to a site in the MCS of the plasmid vector are generated, size separation by agarose gel electrophoresis, isolation of the digested chromosomal DNA in particular size ranges, and ligation into the plasmid vector which had been digested with a restriction enzyme that cuts uniquely in the MCS. Any restriction enzyme or enzymes may be used that are specific to the genomic DNA employed and will give fragments of suitable size and having compatible ends for cloning into the appropriate vector. Restriction enzymes suitable for restriction of enteric bacterial are well known in the art (Sambrook, supra) and include AluI, AvrI, ValI, BamHI, AclI, BglI, ClaI, EcoRI, EcoRV, FokI, HaeII, HaeIII, HincII, HindIII, KnpI, MboI, MboII, NciI, NcoI, NdeI, NheI, NotI, PstI, PvuI, SacI, SacII, Sau3AI, Sau96I, SfiI, SmaI, XbaI, and XhoI.

PCR—primer directed methods

Gene fusions may alternatively be generated by methods of primer directed amplification if some or all of the sequence of the desired promoter or gene is known. Methods of primer directed amplification are well known in the art and include polymerase chain reaction (PCR), ligase chain reaction (LCR) or Strand Displacement Amplification (SDA). If PCR methodology is selected, the replication composition would include for example, nucleotide triphosphates, two primers with appropriate sequences, DNA or RNA polymerase and proteins. These reagents and details describing procedures for their use in amplifying nucleic acids are provided in U.S. Pat. No. 4,683,202 (1987, Mullis et al.) and U.S. Pat. No. 4,683,195 (1986, Mullis et al.). If LCR methodology is selected, then the nucleic acid replication compositions would comprise, for example, a thermostable ligase, e.g., T. aquaticus ligase, two sets of adjacent oligonucleotides wherein one member of each set is complementary to each of the target strands, Tris HCl buffer, KCl, EDTA, NAD, dithiothreitol and salmon sperm DNA. (See, for example, Tabor, S. and Richardson, C. C. (1985) Proc. Acad. Sci. USA 82, 1074-1078.). If the SDA methodology is used, amplification may be accomplished using either one or two short primers containing a site for HincII digestion, an exonuclease deficient DNA polymerase, HincII restriction enzyme and the bases dGTP, dCTP, dTTP and deoxyadenosine 5′[α-thio]triphosphate (dATP[αS]. The SDA protocol including the necessary materials is outlined in Walker et al. ( Proc. Natl. Acad. Sci. U.S.A., 89:392 (1992)).

PCR methods could also be used to generate random segments of DNA if random primers are used with bacterial chromosomal DNA as the template. Such randomly amplified DNA segments (RAPD) would then be ligated into the MCS of the desired plasmid vector.

Transposons

Transposons may also be used to generate collections of gene fusions, using a process of in vivo transposition. Many transposable elements are available that have reporter genes lacking promoter sequences (Berg and Berg, Transposable element tools for microbial genetics, in Escherichia coli and Salmonella Cellular and Molecular Biology , (2588-1612), F. C. Neidhardt, Editor. 1996, ASM Press: Washington, D.C.). Insertion of such transposons randomly throughout a bacterial chromosome will result in chromosomal promoters driving the expression of the reporter gene of the transposon.

Transformation of Suitable Hosts

Once suitable plasmids are constructed they are used to transform appropriate host cells. Introduction of the plasmid into the host cell may be accomplished by known procedures such as by transformation, e.g., using calcium-permeabilized cells, electroporation, transduction, or by transfection using a recombinant phage virus. (Sambrook et al., supra)

In the present invention, plasmid pDEW201 containing random chromosomal DNA was used to transform the E. coli DPD1675 as fully described in the GENERAL METHODS and EXAMPLES.

Transformed hosts—Detector organisms

Detector organisms may include a variety of both prokaryotic and eukaryotic organisms. Preferred are enteric bacteria; most preferred is E. coli.

A suitable bacterial strain with which to test the effects of a chemical is one whose growth is affected by that chemical. Hence, the chemical of interest must be able to enter the cell, be retained in the cell, and interact with target molecules of the cellular machinery. Various mutations of E. coli are known to affect permeation into and accumulation within the cell. Strains carrying mutant alleles of rfa (Ames et al., Proc. Nat. Acad. Sci. USA, 70(3):782-786 (1973)), envA (Young and Silver, J. Bacteriol., 173:3609-3614 (1991)), imp (Sampson et al., Genetics, 122:491-501 (1989)), lpp (Giam et al. J. Biol. Chem., ( 259):5601-5605 (1984) or surA (Tormo et al., J. Bacteriol., ( 172)4339-4347 (1990)) have increased sensitivity to a variety of chemicals. Destruction of efflux pumps, with mutations such as emr (Ma et al., Mol. Microbial., 16:45-55 (1995)), or acrAB (Paulsen et al., Mol. Micro., 19:1167-1175 (1996)), or the channels they use, with mutations such as tolC (Schnaitman et al., J. Bacteriol., 172(9):5511-5513, (1990)), also result in increased chemical sensitivity. In some instances, the target macromolecule of a chemical may be intrinsically resistant to the action of that chemical. For example, E. coli has two isozymes of the enzyme acetolactate synthase (ALS), one of which has a poor binding affinity for the sulfonylurea herbicides. Mutations which destroy the functions of ilvBN, encoding the resistant isozyme, result in a strain with greatly increased susceptibility to growth inhibition by sulfonylurea herbicides that target acetolactate synthase (LaRossa and Smulski, J. Bacteriol., 160:391:394 (1984)). An appropriate host strain of E. coli or other bacteria may be constructed to carry a known mutation or combinations of mutations. Furthermore, an appropriately sensitive strain may also be found by screening for growth inhibition following mutagenesis by transposon insertion or chemical or physical treatments.

The present invention further provides a transformed host cell capable of increased luminescence in the presence of a cellular insult. Many suitable hosts are available where E. coli is preferred and the E. coli strain DPD1675 (ilvB2101 ara thi Δ(pro-lac)tolC::miniTn10) is most preferred. DPD1675 was derived by phage P1 mediated generalized transduction using a lysate growth on strain DE112 (strR, galK2, lac Δ74 tolC::miniTn10) as a donor and strain CU847 (ilvB2101 ara thi Δ(pro-lac)) as a recipient. Resultant tetracycline resistance transductants were screened for hypersensitivity to the hydrophobic compound crystal violet.

Cellular stress—Cellular Insults

The present invention provides a method for the detection of bacterial regulator elements responsive to a variety of cellular stresses (produced by cellular insults) such as those produced when a cell contacts chemicals, such as herbicides, crop protection chemicals, environmental pollutants, heavy metals, changes in temperature, changes in pH, agents producing oxidative damage, insults causing DNA damage, insults causing anaerobiosis, and biological insults such as the pathogenic life forms (viruses, bacteria, etc.). Preferred regulatory regions will be responsive to chemicals used in the agrochemical industry such as CPC's including herbicides. The regulatory regions identified include those responsive to sulfonylurea herbicides and sulfonanilide herbicides (chlorsulfuron, triasulfuron, metsulfuron-methyl) and glyphosate, phosphinothricin, asulam, and quizalofop. It is contemplated that regulatory regions responsive to other agrochemicals may also be identified by the present method including but not limited to pesticides (paraquat, copper sulfate, metidathion), anti-pathogenic compounds such as fungicides (chlorothalonil), chemicals responsible for insect behavior modulation (pheromones, allomonese and kairomones), auxin herbicides (e.g. dicamba, 2-methyl-4-chlorophenoxyacetic acid, picloram, quinclorac, quinmerac), pre-emergence herbicides (metribuzin), and post-emergence herbicides (Clethodim Pendimethalin, oryzalin, dithiopyr, oxadiazon, prodiamine, 2-4-D).

Culture Conditions

Typically cells are grown at 37° C. in appropriate media. Preferred growth media in the present invention are common defined media such as Vogel-Bonner medium (Davis et al., Advanced Bacterial Genetics 1980, Cold Spring Harbor, N.Y.:Cold Spring Harbor Laboratory). Other defined or synthetic growth media may also be used and the appropriate medium for growth of the particular microorganism will be known by someone skilled in the art of microbiology or fermentation process.

Suitable pH ranges for bacterial growth are between pH 5.0 to pH 9.0, where pH 6.0 to pH 8.0 is preferred as the initial condition.

Growth of the bacterial cells in liquid medium allows a uniform population of cells to be stressed at various growth phases such as early log phase, mid log phase, late log phase or stationary phase. Stress if the condition produced in a cell as the result of exposure to a cellular insult. This cellular insult may be caused by any substance or change in the cellular environment that results in an alteration of normal cellular metabolism in a bacterial cell or population of cells. The addition of chemicals such as herbicides, crop protection chemicals, environmental pollutants, or heavy metals to the growth media can cause such an insult. Additionally, changes in temperature, changes in pH, agents producing oxidative damage or DNA damage (such as from UV exposure), anaerobiosis, or changes in nitrate availability may cause insult as well.

Identification of regulatory regions

Genomic segments containing regulatory regions responsive to an cellular insult are identified by screening for altered luminescence following application of the cellular insult to individual isolates of the transformed host cells containing random chromosomal DNA fragments. A genomic segment is identified as containing a regulatory region it its presence upstream of the reporter gene(s) results in increased or decreased activity of the reporter gene(s) after application of the cellular insult to cells containing the genetic fusion. The genomic segment present in a particular plasmid is identified by the sequence of the ends of the chromosomal DNA fragment. The regulatory region, therefore, is a genomic segment located between those ends. Smaller genomic segments within that originally defined region will also likely be sufficient to function as the regulatory region. These smaller segments are identified by the altered activity of a reporter gene(s) following application of the environmental insult to cells containing a genetic fusion of the regulatory region to a reporter gene(s). The regulatory region may also be identified as the region responsible for altered messenger RNA or protein synthesis from the stress gene following application of the environmental insult to cells.

The application of the invention to discovery of E. coli genomic segments containing regulatory regions responsive to the herbicide sulfometuron methyl and 2,4-dichlorophenoxyacetic acid are described in detail in the GENERAL METHODS and EXAMPLES. A number of previously unidentified regulatory regions were discovered. These regulatory regions are contained within the chromosomal DNA fragment cloned into the multiple cloning site of pDEW201. However, it is likely that smaller segments of chromosomal DNA would be sufficient to function as the regulatory region. These are identified as the genomic segment responsible for increased transcription of the stress gene, which may be quantitated by increased activity of a reporter gene(s) in a genetic fusion, increased messenger RNA synthesis or increased protein synthesis.

Genomic segments containing regulatory regions responsive to other chemicals are found by this method also. In particular, it is expected to be useful to discover such segments responsive to crop protection chemicals that are known to inhibit metabolic processes that are in common to bacteria and plants. These would include, but are not limited to, glyphosate, an inhibitor of ESPS synthase (5-enolpyruvyl-shikimicacid-3-phosphate synthase)( Biochem. Biophys. Res. Commun. 94:1207-12 (1980)), phosphinothricin, an inhibitor of glutamate synthase (Baron et al., Plant Physiol. Biochem. (Paris)( 1994), 32(4):555-60), asulam (Kidd et al., Plant Sci. Lett. (1982), 26(2-3), 211-17), a folate biosynthesis inhibitor, and quizalofop-ethyl, an inhibitor of acetyl CoA carboxylase (Dehaye et al., Eur. J. Biochem. 225:1113-23 (1994).

Discussion of the Preferred Embodiments

The data shown in FIGS. 2 and 3 demonstrate a key feature of this method: promoters of a wide range of activity are readily detected and quantitated by the resultant light production. An advantage of this method is that promoters of varied activities may all be measured with the same conditions at the same time. Furthermore, the activity of collections of such promoters can be screened for changes following cellular stress. An example, the SM induction of a strain identified by this method, is shown in FIG. 4 . It is not likely that this strain or others would have been identified by screening on plates, as typically done. This is shown in FIG. 6 where the bioluminescence of several strains identified by this method was recorded following growth on plates containing SM. Increases of bioluminescence on the SM-containing plates were not detected. This is may be in part because of the decreased amount of growth in the presence of the chemical. In fact, higher concentrations of SM (≧3 μg/mL) that were useful for characterizing fusion-containing strains in liquid medium could not be used on the plates because little to no growth resulted.

FIG. 6 shows another aspect of this invention. Various herbicidal chemicals were used to stress SM-inducible fusion containing strains identified by this method. A pattern of induction for each herbicidal chemical was observed. It was noted that two chemicals, SM and glyphosate, gave very similar patterns of induction. Thus, these fusion-containing strains may be useful as screens for compounds that will be effective herbicides. Furthermore, these fusion containing strains also may be useful for characterizing the modes of action of herbidcides or potential herbicides.

The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

EXAMPLES

General Methods

Procedures for phosphorylations, ligation and transformations are well known in the art. Techniques suitable for use in the following examples may be found in Sambrook et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press (1989).

Materials and methods suitable for the maintenance and growth of bacterial cultures are well known in the art. Techniques suitable for use in the following examples may be found in Manual of Methods for General Bacteriology (Phillipp Gerhardt, R. G. E. Murray, Ralph N. Costilow, Eugene W. Nester, Willis A. Wood, Noel R. Krieg and G. Briggs Phillips, eds), American Society for Microbiology, Washington, D.C. (1994) or Thomas D. Brock in Biotechnology: A Textbook of Industrial Microbiology, Second Edition (1989) Sinauer Associates, Inc., Sunderland, Mass. All reagents and materials used for the growth and maintenance of bacterial cells were obtained from Aldrich Chemicals (Milwaukee, Wis.), DIFCO Laboratories (Detroit, Mich.), GIBCO/BRL (Gaithersburg, Md.), or Sigma Chemical Company (St. Louis, Mo.) unless otherwise specified.

The meaning of abbreviations is as follows: “h” means hour(s), “min” means minute(s), “sec” means second(s), “d” means day(s), “mL” means milliliters, “L” means liters, μL means microliters, and μg means micrograms.

Example

1. Construction of a Promoter Probe Vector

Plasmid pDEW201 was made by replacing the promoterless lacZ gene of pRS415 (Simons et al., Gene, 53:85-96 (1987)) with the promoterless Photorhabdus luminescens luxCDABE from pJT205 (Rosson, PCT International Application WO 93/03179, 57 pp., (1993)). Plasmid pRS415 contains an origin of replication from pBR322, a bla gene and four tandem transcription terminators from phage T1 upstream of a multiple cloning site (MCS). This plasmid DNA was digested with BamH I, Nru I and EcoR V and ligated with pJT205 DNA that had been digested with BamH I, Pvu II and Pst I. The ligation mixture was used to transform E. coli strain DH5, selecting for ampicillin resistance. Light production from overnight cultures of transformant colonies that had been grown in LB medium containing 150 μg/mL of ampicillin was quantitated in a ML3000 luminometer in the presence and absence of 0.0033% nonanal. Plasmid DNA was isolated from three transformants that had very low levels of light production (0.0022 to 0.0029 RLU) in the absence of nonanal and moderate light production (0.91 to 0.97 RLU) in the presence of nonanal. Restriction digestion analysis with various enzymes and combinations of enzymes showed that each of these three plasmids had the expected structure except that a portion (c.a. 900 bp) near the 3′ terminus of the luxCDABE operon containing an EcoR I site was deleted. One of these plasmids was saved and named pDEW201. The entire luxCDABE operon is known to remain intact in pDEW201 because placement of DNA with promoter activity in the multiple cloning site results in light production in the absence of exogenously added aldehyde. Furthermore, DNA sequence analysis of the 3′ region of the lux operon in pDEW201 showed that the join point of the sequences derived from pJT205 to sequences derived from pRS415 was one nucleotide beyond the termination codon of luxE.

A map of plasmid pDEW201 is shown in FIG. 1 . Features of this plasmid include: (1) unique EcoR I, BamH I, Kpn I and Sac I sites in the multiple cloning site; (2) promoterless Photorhabdus luminescence luxCDABE genes downstream of the multiple cloning site; (3) transcription terminators upstream of the multiple cloning site resulting in a very low level of read-through transcription and hence very low light production in the absence of promoter DNA cloned into the multiple cloning site from cells containing this plasmid; (4) ampicillin resistance selection for maintenance of the plasmid; and (5) moderate copy number due to the replication origin from pBR322.

2. Construction of Libraries

Chromosomal DNA isolated from E. coli W3110 was partially digested with restriction enzyme Sau3 A1 and size fractionated on agarose gels. Fractions of three size ranges (average sizes of approximately 700, 1800 or 2500 basepairs) were ligated to pDEW201 that had previously been digested with restriction enzyme BamHI and treated with calf intestinal alkaline phosphatase. The ligation products were used to transform ultracompetent E. coli XL2Blue (Stratagene) to Amp R (ampicillin resistant). Pooled transformants were cryogenically preserved and used to isolate plasmid DNA.

3. Characterization of Libraries of Cloned Random DNA Upstream of lux

Single ampicillin resistant transformants of E. coli XL2Blue were toothpicked from transformation plate to wells of a white microtiter plate containing 100 μl of LB medium (Miller, Experiments in Molecular Genetics, 1972, Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory). Light production was quantitated in an ML 3000 luminometer and compared with control pDEW201 transformants. Those with greater light production than the control were scored Lux + . The results are shown in Table I.

TABLE I
Library	approx. size of inserted DNA	#Lux + /total picked	% Lux +
Z	500-2000	21/88	24%
A	900-3000	49/88	56%
B	1500-4500	60/88	68%

As expected, there were a greater percentage of cloned fragments with promoter activity, hence light production, as the size of inserted DNA was increased.

Light production and insert size from 16 random individual transformants of libraries A and Z grown overnight in LB medium containing 150 μg/mL ampicillin was characterized. Bioluminescence from two 100 μL samples was quantitated, averaged and compared with the bioluminescence of pDEW201 transformants. The remaining 4.8 mL of the overnight culture was used to isolated plasmid DNA, which was subsequently digested with restriction enzymes EcoRI and SacI to release the fragment inserted into the MCS. Table II below summarizes the findings.

TABLE II
		range		Insert size	Avg.
Library	Lux + /total	of RLU	Insert + /total	range, kbp	insert size
Z	9/16 (56%)	0.001-3.0	16/16	0.1-1.5	0.7 kbp
			(100%)
A	11/16 (69%)	0.015-27	16/16	0.9-3.0	1.8 kbp
			(100%)

FIGS. 2 and 3 display the light production as a function of insert size for these transformants. The large range of light production indicates that promoters of many strengths are present in the libraries. Furthermore, it demonstrates the advantages of the large dynamic range of the lux reporter in that these varied plasmids containing promoters of varied activities could all be measured with the same conditions at the same time.

4. Identification of Appropriate E. coli Host Strains

To discover the effects of chemicals on the cell without presupposition concerning the nature of those effects, the host strain should be as close to wild type as possible. Nevertheless, certain features are important. In order for the growth of E. coli to be inhibited by the sulfonylureas, such as sulfometuron methyl (SM), the SM-resistant ALS I must be eliminated by an ilvB − mutation. Another desirable feature is increased sensitivity to chemicals. E. coli strains mutated in tolC lack the outer membrane channel for an hydrophobic compound efflux pump and thus are sensitive to growth inhibition at reduced chemical concentrations. The E. coli strain DPD1675 [ilvB2101 ara thi Δ(p{dot over (r)}o-lac) tolC::miniTn10], has both an ilvB − mutation and a tolC − mutation with few other mutations.

5. Screening for SM-inducible Promoters

Plasmid library A was used to obtain AmpR transformants of E. coli DPD1675. These transformants, each of which contained random, individual plasmids with E. coli DNA fused to the lux reporter, were toothpicked to wells of a microtiter plate. Each well contained 100 μL of Vogel-Bonner (Davis et al., Advanced Bacterial Genetics, (1980), Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory) with glucose as a carbon source and supplemented with thiamine, uracil, proline and 25 μg/mL ampicillin. Following overnight growth at 37° C., these pure cultures were used for both permanent storage (Menzel, Anal. Biochem., 181:40-50 (1989)) and dilution and regrowth to exponential phase in the same medium except containing 10 μg/mL ampicillin. These actively growing cultures were tested for the effects of SM addition by adding 50 μL to 50 μL of fresh medium lacking ampicillin but containing 4 μg/mL SM (E. I. du Pont de Nemours, Wilmington, Del.). The final SM concentration, 2 μg/mL, resulted in partial (25%) inhibition of E. coli DPD1675 growth rate. Light production was quantitated in a ML3000 luminometer at 0, 90, and 180 min of incubation at 37° C. after addition of cell cultures to chemical. The criteria of Table III were used to identify putative SM-inducible fusions.

TABLE III
RLU (SM treated) − RLU (control) RLU (SM treated)/RLU (control)
ΔRLU 0.02 → 0.1                  Ratio ≧ 1.50
ΔRLU 0.1 → 1.0                   Ratio ≧ 1.35
ΔRLU 1.0 → 10.0                  Ratio ≧ 1.25
ΔRLU > 10.0                      Ratio ≧ 1.20

Putative transformants were reisolated from the appropriate wells of the duplicate cultures stored at −80° C. and retested under the same conditions as above. Those that showed SM-induced increased bioluminescence in the second test were tested at third time at a variety of SM concentrations and for a longer extent of time. An example of induction of bioluminescence from one of these fusions is shown in FIG. 6 . Strains that continued to show good SM induction were selected for further analysis including DNA sequencing to identify the inserted DNA in the plasmid. Of the 8066 random fusion containing transformants that were screened, twenty were selected for DNA sequence analysis.

6. DNA Sequence Analysis

The DNA sequence information from both ends of the inserted DNA was analyzed by comparison with the E. coli chromosomal sequence using the ECDC database (Kröger and Wahl, Nucleic Acids Res.: 24:29-31 (1996 )). A summary of the identities of the twenty inducible fusions is shown in Table IV. In all cases where the sequence was identified, the promoter closest to the lux reporter genes was situated such that the transcription initiated at that promoter would drive lux expression. The 17 single insert fusions represent 13 unique fusions of DNA with promoter activity to luxCDA{dot over (B)}E.

Sequence data was obtained by automated DNA sequencing. For those sequences labeled “upper” the primer, GGATCGGAATTCCCGGGGAT (SEQ ID NO: 27), from just upstream of the MCS of pDEW201 was used. For those sequences labeled “lower”, the primer, CTGGCCGTTAATAATGAATG (SEQ ID NO: 28), from the luxC region of pDEW201 was used. The sequences listed are those used for comparison with the E. coli sequence database. For the upper sequences, it starts about 30 bases into the sequence and continues to the first ambiguous base (N). For the lower sequences, it starts immediately after the BamHI site and continues to the first ambiguous base (N). In some cases, a few ambiguous bases (N) may be included. All sequences are shown 5′ to 3′.

TABLE IV
DNA Sequence Analysis of 20 SM-Inducible Genes
	Sub-		Other
Total	fusions	Categories	Information
3	—	Double insert =>
		No further analysis
		(3 of 3 fusions)
3	—	No hits to database
		(3 of 3 fusions)
		Unique (1 of 3
		fusions) Identical
		to each other (2 of 3
		fusions)
4	—	Hit at one end only	Downstream of ack
		(4 of 4 fusions)	Downstream of glk
		(upper primer
		sequence)
		51.49 min
		(1 of 4 fusion)
		52.31 min
		(3 or 4 fusions)
6 “unknown” orfs
	1 ldcH	4.5 min	Predicted function:
			lysine decarboxylase
	1 yciG	28.2 min	Predicted function:
			unknown
	2 yohF	47.4 min	Predicted function:
			dehydrogenase
	1 yiaB	80.3 min	Predicted function:
			unknown
	1 frvx	88.1 min	Predicted function:
			unknown
4 known genes
	1 poxB	19.6 min	Pyruvate oxidase
			Regulated by rpoS
	1 inaA	50.0 min	Function: not known
			Induced by acid shock
			and other environ-
			mental insults Reg-
			ulated by soxRS and
			mar
	1 sohA	70.6 min	Activation of the Lon
			protease Auto
		a.k.a. prlF	regulated
	1 osmY	99.3 min	Periplasmic protein
			induced by hyper-
			osmotic insult
			Regulated by rpoS,
			lrp, cAMP, and IHF

7. Functional Grouping of Fusion Containing Strains

Each of the 13 unique single insert fusion strains was characterized by testing actively growing cells in Vogel-Bonner medium with glucose as the carbon source supplemented with thiamine, proline and uracil challenged with final concentration of chemicals: 3 or 8 μg/mL SM or 5 mM salicylate, a weak, membrane-permeant acid. Bioluminescence was quantitated for ≧1000 min in an ML3000 luminometer at 37° C. in plates covered with acetate seals. Data from plots of RLU vs. time were analyzed calculating “very early” induction ratios and “peak” response ratios. The ratio of the RLU from treated samples (with SM 3 μg/mL or Salicylate 5 mM) at the 90 min time point to the control RLU at the 90 min time point was the “very early” induction ratio; the fusion was considered induced if this ratio was >1.3. The ratio of the peak RLU of treated cells (with SM 8 μg/mL or Salicylate 5 mM) at any time point in the experiment to the peak RLU at any time point of the control cells was the “peak” response ratio; the fusion was considered induced if this ratio was >1.5. Also calculated was the ratio of the RLU peak of the untreated cells to the RLU of the untreated cells at the second cycle (1000 sec) of the experiment. Table V shows the classes of fusions from this data.

TABLE V
Classes of fusion strains
“Class 1” Stationary phase inducible (and putatives)
		SM	Salicylate	Overnight	Genomic
		induction	induction	peak/initial	Segment
		RLU (SM)/	RLU (Sal.)/	RLU (second	bounded by
Strain	Fusion	RLU control	RLU control	cycle)	SEQ ID NOS:
DPD3509	poxB′::lux	Very early only:	Very early only:	17/0.5 = 34X	23 and 24
	(pyruvate oxidase)	1.9/1.3 = 1.5 X	2.9/1.3 = 2.2X
DPD2090	osmY′::lux	Very early only:	Very early only:	1.6/0.05 = 32X	13 and 14
	(outer membrane	0.12/0.08 = 1.5X	0.12/0.08 = 1.5X
	protein)
DPD2088	yohF′::lux	Very early:	Very early only:	4.3/0.2 = 22X	9 and 10
	(putative dehydro-	0.6/0.3 = 2X	0.6/0.3 = 2X
	genase)	Late (slight):
		7.4/4.3 = 1.7X
DPD3505	unmapped	Very early only:	Not induced	7.2/0.35 = 21X	19 and 20
	(no clues from	1.1/0.7 = 1.6X
	protein database)
“Class 2” Acid inducible (and putatives)
				Overnight	Genomic
				peak/initial	Segment
		SM	Salicylate	RLU (second	bounded by
Strain	Fusion	induction	induction	cycle)	SEQ ID NOS:
DPD2087	inaA′::lux		Very early	90/10 = 9X	7 and 8
	(acid inducible,		(strong):
	unknown func.)	Moderate late:	130/25 = 5.2X
		200/90 = 2.2X	Late:
			325/90 = 3.6X
DPD3507	sohA′::lux		Very early:	80/10.5 = 7.6X	21 and 22
	(Lon activator)		42/22 = 1.9X
		Moderate late:	Late (Slight):
		160/80 = 2X	155/80 = 1.9X
DPD3501	frvX′::lux		Very early:	10/1.2 = 8.3X	17 and 18
	(unknown function)		4/2.6 = 1.5X
		Moderate late:	Late (Slight):
		24/10 = 2.4X	17.5/10 = 1.8X
DPD2089	unmapped	Very early:	Very early:	18/6 = 3X	11 and 12
	(no clues from	11.0/7.5 = 1.5X	19.5/7.5 = 2.6X
	protein database)	Moderate late:	Late (Slight):
		55/18 = 3.1X	30/18 = 1.7X
DPD3512	ldcH′::lux	Very early:	Very early:	2.5/0.38 = 6.6X	25 and 26
	(putative lysine	1.2/0.6 = 2X	1.05/0.6 = 1.8X
	decarboxylase)	Moderate late:	Late (Slight):
		10.2/2.5 = 4.1X	4.5/2.5 = 1.8X
“Class 3” Stationary phase (very strong) and acid inducible (putative)
				Overnight	Genomic
				peak/initial	Segment
		SM	Salicylate	RLU (second	bounded by
Strain	Fusion	induction	induction	cycle)	SEQ ID NOS:
DPD2092	downst. of ack	Very early:		15/0.06 = 250	15 and 16
	(putative	0.99/0.72 = 1.4X
	transmembrane	Late:	Late only:
	protein)	130/15 = 8.7X	50/15 = 3.3X
“Class 4” Possible SM-specific induction
				Overnight	Genomic
				peak/initial	Segment
		SM	Salicylate	RLU (second	bounded by
Strain	Fusion	induction	induction	cycle)	SEQ ID NOS:
DPD2084	yciG′::lux	Very early:	Not induced	0.7/0.09 = 7.8X	3 and 4
	(unknown function)	0.18/0.11 = 1.6X
		Moderate late:
		1.5/0.7 = 2.1X
DPD2086	yiaB′::lux	Very early only	Not induced	0.45/0.085 = 5.3X	5 and 6
	(unknown function)	(v. slight):
		0.17/0.15 = 1.1X
“Class 5” Generally inducible by many stresses
				Overnight	Genomic
				peak/initial	Segment
		SM	Salicylate	RLU (second	bounded by
Strain	Fusion	induction	induction	cycle)	SEQ ID NOS:
DPD2081	downst of glk	Very early:	Early:	0.35/0.2 = 1.8X	1 and 2
	(putative fructose	0.5/0.2 = 2.5X	0.35/0.2 = 1.8X
	specific iic	Late:	Late:
	component of pts)	3.6/.35 = 10.3X	1.5/0.35 = 4.3X
“Control” Non-SM inducible, heat shock promoter
				Overnight
				peak/initial
		SM	Salicylate	RLU (second
Strain	Fusion	induction	induction	cycle)
DPD2077	grpE′::lux	None	Very early:	340/48 = 7.1X
			250/80 = 3.1X
			Moderate late:
			700/340 = 2.1X

8. Induction by Other Herbicides

Representative fusions from some of the classes above were tested for induction by other herbicidal compounds. Strains DPD3509 (poxB′::luxCDABE), DPD2087 (inaA′::lux), and DPD2081 (map position of fusion is downstream of glk) were grown in Vogel-Bonner medium with glucose as the carbon source supplemented with thiamine, proline and uracil until mid-log phase. These cultures were challenged with SM, glyphosate (Sigma, St. Louis, Mo.), phosphinothricin, asulam, or quizalofop-ethyl (Chem Services, West Chester, Pa. 19381). Bioluminescence was quantitated for >1000 min in an ML3000 luminometer at 37° C. in plates covered with acetate seals. Data from plots of RLU vs. time were analyzed calculating “early” and “peak” responses. The difference of the RLU from treated samples (SM 8 μg/mL, glyphosate 100 μg/mL, phosphinothricin 200 μg/mL, asulam 50 μg/mL or quizalofop-ethyl 50 μg/mL at the 200 min time point from the control RLU at the 200 min time point was normalized by dividing by the RLU of the control sample at that time point to give the “early” response: $$ RLU ⁢   ⁢ ( treated , 200 ⁢   ⁢ min ) - RLU ⁢   ⁢ ( control , 200 ⁢   ⁢ min ) RLU ⁢   ⁢ ( treated , 200 ⁢   ⁢ min )

The difference of the peak RLU of treated cells (SM 16 μg/mL, glyphosate 100 μg/mL, phosphinothricin 200 μg/mL, asulam 50 μg/mL or quizalofop-ethyl 50 μg/mL) at any time point in the experiment to the peak RLU at any time point of the control cells was normalized by dividing by the peak RLU of the control sample to give the “peak” response: $$ RLU ⁢   ⁢ ( treated , peak ) - RLU ⁢   ⁢ ( control , peak ) RLU ⁢   ⁢ ( treated , peak )

FIG. 5 displays the results of these calculations; values less than zero are not shown. Each herbicide gives a pattern of induction of these three fusions that is unique. However, the similarity of pattern between SM and glyphosate is noted.

9. Bioluminescence Detection on Plates

The described method of discovery of promoters by inducing stress in cells growing in liquid medium is more sensitive than assessing activity of the reporter genes on petri plates. This was shown by testing several of the SM-induced fusion containing strains. E. coli strains DPD2084, DPD2081, DPD2088, DPD3512, and DPD2092 were streaked for single colonies on Vogel-Bonner medium agar plates with glucose as the carbon source and supplemented with thiamine, proline, uracil and ampicillin (25 μg/mL). Six single colonies of each were transferred with a toothpick to the plates of the same composition except lacking ampicillin and containing SM at 2 μg, 1 μg/mL, 0.5 μg/mL or 0 μg/mL. Following incubation at 37° C. overnight, there was visible growth on all plates; however, the growth on the plates containing SM was visibly less dense. These plates were exposed to X-ray film (DuPont REFLECTIONS, Wilmington, Del.) at 37° C. for two h. The film was developed and examined visually. There was no increase in darkening of the film for any of these five strains on the plates with SM compared with those plates lacking SM. An image of the exposed and developed X-ray film was made by illuminating it on a light box, capturing an electronic image using the Eagle Eye™ II (Stratagene) system. Colors corresponding to the various exposures of the film were added to the image using a Macintosh QUADRA 800 computer and the public domain NIH Image program (written by Wayne Rasband at the U.S. National Institutes of Health and available from the Internet by anonymous ftp from zippy.nimh.nih.gov or on floppy disk from NTIS, 5285 Port Royal Rd., Springfield, Va. 22161, part number PB93-504868). These version of the relative bioluminescence of these E. coli strains grown on plates is shown in FIG. 6 . As with visual examination of the film, there is no evidence of increased bioluminescence on the plates with SM compared with those plates lacking SM. Thus, it is unlikely that any of these five strains would have been scored SM-inducible by a plate assay.

10. Identification of Regulatory Regions Responsive to 2,4-dichlorophenoxyacetic Acid

This method is also useful for discovery of regulatory regions modulated by other chemicals. This was shown by identification of fusion-containing strains showing bioluminescence which was inducible by the herbicidal compound 2,4-Dichlorophenoxyacetic acid. Plasmid libraries Z, A, and B were used to obtain ampicillin resistant transformants of E. coli DPD1675. These transformants, each of which contained random, individual plasmids with E. coli DNA fused to the lux reporter, were grown in wells of a microtiter plate. Each well contained 100 μL of Vogel-Bonner medium (Davis et al., Advanced Bacterial Genetics, (1980), Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory) with glucose as a carbon source and supplemented with thiamine, uracil, proline and 25 μg/mL ampicillin. Following overnight growth at 37° C., these pure cultures were used for dilution and regrowth to exponential phase in the same medium except containing 10 μg/mL ampicillin. These actively growing cultures were tested by adding 50 μl to 50 μL of fresh medium lacking ampicillin but containing 100 μg/mL 2,4-Dichlorophenoxyacetic acid (Janssen Chimica). The final 2,4-Dichlorophenoxyacetic acid concentration was 50 μg/mL. Light production was quantitated in a ML3000 luminometer at 0, 1, 2, and 3 hours of incubation at 37° C. after addition of cell cultures to chemical. Eighty-eight transformants from each library (Z, A, and B) were tested. The Ratio of RLU in the treated sample to RLU in the untreated sample was calculated, as was the difference in RLU of the treated sample from the untreated. Fusion-containing strains which gave a ratio greater than or equal to 1.2 and an increase in RLU greater than 0.1 were scored as 2,4-Dichlorophenoxyacetic acid-inducible. Table VI list the results of 2,4-Dichlorophenoxyacetic acid-inducible isolated identified.

TABLE IV
Gene fusion		Time of
Library	Isolate #	Treatment	Ratio	Increase in RLU
Z	Z1-C4	1 h	2.1	2.5
	Z1-E11	1 h	1.2	2.0
	Z1-C11	2 h	1.5	0.3
A	A1-H2	1 h	1.3	25.2
	A1-F7	1 h	1.2	4.5
B	B1-D3	2 h	1.3	23.9
	B1-A8	3 h	1.3	0.3
	B1-E8	3 h	1.7	14.1
	B1-F9	2 h	1.4	1.8

28 150 base pairs nucleic acid single linear DNA (genomic) unknown DPD2081 upper 1TTTGGTGGCG CAGAACCGGT CGAAGGTAAG CCTATTGCGG TTTACGGTGC CGGAACGGGG 60CTTGGGGTTG CGCATCTGGT CCATGTCGAT AAGCGTTGGG TAAGCTTGCC AGGCGAAGGC 120GGTCACGTTG ATTTTGCGCC GAATAGTGAA 150 95 base pairs nucleic acid single linear DNA (genomic) unknown dpd2081 lower 2CCCATTGCGT ACATCAGCGC GCCCTTCTCA CCTGCGGCAG TCAGCACAGT ACGGATACCG 60CCGTTGATCC AGCCACCAAA GGGGGTGATG ACGTA 95 414 base pairs nucleic acid single linear DNA (genomic) unknown dpd2084 upper 3ATTCAAAACG CCACTCTGCG CGCCTTTGCG GCAGGTGTGA CTCCGGCACA ATGTTTTGAA 60ATGCTGGCAC TGATTCGCCA GAAACACCCG ACCATTCCCA TTGGCCTGTT GATGTATGCC 120AATCTGGTGT TTAACAAAGG CATTGATGAG TTTTATGCCC AGTGCGAAAA AGTCGGCGTC 180GATTCGGTGC TGGTTGCCGA TGTGCCAGTT GAAGAGTCCG CGCCCTTCCG CCAGGCCGCG 240TTGCGTCATA ATGTCGCACC TATCTTCATC TGCCCGCCAA ATGCCGATGA CGACCTGCTG 300CGCCAGATAG CCTCTTACGG TCGTGGTTAC ACCTATTTGC TGTCACGAGC AGGCGTGACC 360GGCGCAGAAA ACCGCGCCGC GTTACCCTCA ATCATCTGGT TGCGAACTGA AAGA 414 283 base pairs nucleic acid single linear DNA (genomic) unknown dpd2084 lower 4ATTTTTAAAA TTACCGCCGC TATGCTGACC GCCTTTACGG CCTGCGTCGG ATGCCTTCTC 60ACGGTCTTCG GCGAAATTTC CTGAACCACC ACGATGTTCG GCCATGTTAT TTCTCCCGTT 120GCGTTGCATT GTTTCATTAA TATGAGTGTT GTGTGTCGAC ACTCATTAAA ATTAGTCGCT 180AATGAGAATT AGTCAAATTA AGCGCAACGA GAAGATAGAG GGAAAATATA TTTTGAGGAA 240CATTCTGGAT ATATTAACAA TTACCTGAGG AATAAGTGAC TTA 283 185 base pairs nucleic acid single linear DNA (genomic) unknown dpd2086 upper 5CGCGATGGAT ACGATGGCAC TGGCGCTGAA ATTGCGCGCG CATGATTGAA ATGGCAAGCT 60GGAAAACGCA TCGCGCACGT TATTCCGGCA TGGAATAACG AATTGGGCCA CCAAATCCGA 120AAGGCCGGTG TCACTGGCAA TTTAGCCAAA TATGCTCAGG AACATCATGT GTCTCCGGTG 180CATCA 185 479 base pairs nucleic acid single linear DNA (genomic) unknown 6TCCATATCTA CCAGCGATAC ATTACGAGTA ACCAACGAAA GACAAAACTG AAAAATGCCA 60TTAACAAATG ATTTTCAGAA TAAATTCATA CTAAATATTA ATTAATTACT GAGATATATA 120GATGTGAATT ATCCCCCACC CGGTCAGGCA GGGGATAACG TTTACGCCAT TAATGGCAGA 180AGTTGCTGAT AGAGGCGACG GAACGTTTCT CGTCGTGGCT GATAAGCGGC ATAACGCTGC 240GCATCTGGTA GATGCGACTG TTCTAACGGT AGTTGCGGCA ACAATTCAAT GAGCGATTTC 300TCTGGATTCG CCGCGATCTG CGCCAGCCTT GCTGCGCCCA GTGCTGGCCC CACATCCCCC 360CCCGTACGGT AATCGAGCTG CTGACCGCTG ATATCCGCCA GCATCTGACG CCAGTACTCA 420CTACGCGCCC CGCCCCCAAT CAACGTAACA CTTTGCGGTT TAATACCGCA GGCATGCAC 479 533 base pairs nucleic acid single linear DNA (genomic) unknown dpd2087 upper 7TCGTTACTAC GCGATAGATT TCACGCTGGA TGAAATTAAG TCGTTGAAAT TTACCGAAGG 60TTTCGATATT GAAAACGGTA AAAAAGTGCA GACTTATCCG GGGCGTTTCC CAATGGGTAA 120GTCCGACTTC CGGGTGCACA CCTTTGAAAA AGAGATTGAA TTTGTTCAGG GGTTAAATCA 180CTCTACCGGG AAAAATATCG GTATTTATCC AGAAATCAAA GCGCCGTGGT TCCATCATCA 240GGAAGGGAAG GATATTGCGG CAAAAACGCT GGAAGTGCTG AAGAAATATG GTTACACCGG 300TAAAGACGAT AAAGTTTATT TGCAATGTTT TGATGCTGAT GAGCTGAACG TATTAAGAAT 360GAGCTGGAAC CCAAAATGGG CATGGAGCTC AATCTGGTAC AGCTGATTGC CTATACCGAC 420TGGAATGAAA CGCAGCAGAA ACAGCCGGAT GGAACTGGGT TAATTACACT ACGACTGGAT 480GTTTAACCGG GTGCCATGAA ACAGGTGGCG GAATATGCAG ATGGTATTGG TCC 533 183 base pairs nucleic acid single linear DNA (genomic) unknown dpd2087 lower 8TTCGGCACGA TGACACCGGC CCGTTCCAGT TCTTTAATTA CCGCAACCTC ACGGACAATC 60GTTGGTCGGC CGAACGGATA ACGTACGGAA TGAAACAGAT GATGCGTCAT GCGCTTTACA 120TACAGCTTTT TGCCGTTGCG CTCGACGCAT TGCACCCCGC TCATACCATT ACGGCGATAG 180TTA 183 174 base pairs nucleic acid single linear DNA (genomic) unknown dpd2088 upper 9CAGTGATGAT TGGTCGCGGG GCGCTCAATA TTCCCAACCT GAGCCGGGTG GTAAAATATA 60ACGAACCGCG AATGCCGTGG CCGGAGGTGG TTGCTTTGCT GCAAAAATAT ACCCGTCTGG 120AAAAGCAGGG CGATACCGGG TTATATCACG TTGCGCGGAT TAAACAGTGG TTGA 174 219 base pairs nucleic acid single linear DNA (genomic) unknown dpd2088 lower 10CCGAATCGGA GGCGGTAATA ATCGCAACCT GTGCCATCGA GTTCTCCACT TAACGCTGAA 60TAAACGTTAA GTATAGAAGG CGCATATCAT CAGCGTTTGT ACCCCCCGCC CAACGCACCA 120GTGAGTTGAA TGGAGGCATC CAGCCACTGC CCTTGCAATA ACAGGCCATT GGCCCGCTCA 180CGCAGCGCGG GGATTCTGGC TTCGCTGACG CGGGAACCA 219 229 base pairs nucleic acid single linear DNA (genomic) unknown dpd2089 upper 11GATTTGCTAT CGAAACCATT CTCATTTTTG TGACAGGTTC GTCGTCACTA TATGGCTACG 60ATAAATAAGG GTGGTAAGCA TTAACAATCC AGGGTAATGG GTGAGGCGAG AGTAAGACGG 120TAACAGACAT ATCTTCTTGT GTCTTTCTTT TAATACCAAA ACATAACCGT TTCTTACATT 180GATAAAAAAT GGAAAAAGTT GAACACTAGT TGGCGAAAAA TCTTGTATA 229 205 base pairs nucleic acid single linear DNA (genomic) unknown dpd2089 lower 12TAACCCATTA ATTATTGAGC ATAATGTAGG CAGTACAAAA TAAGTTAGGC GGGATATCAG 60GCGTCAAGAA TGGAACGAGA ACTCTCCATT CTTGACACCT GATATTGCGG ACATAATAAG 120AAAGCATAAC GCCTGAAATG CTCACTTTGC ATCAGCATGG TGATACAGCT GATGTTTATT 180CTAAAACCTT ACTCAAGTTC TAAGA 205 186 base pairs nucleic acid single linear DNA (genomic) unknown dpd2090 upper 13GCTTTCCGAA GAGGGCGCGG TGCAGGTGTT CCGTCCAATC TCCAACAACG ATCTGATCGT 60TGGTGCAGTT GGTGTGCTGC AGTTTGATGT GGTGGTAGCG CGCCTGAAGA GCGAATACAA 120CGTTGAAGCA GTGTATGAGT CAGTCAACGT TGCCACTGCC CGCTGGGTAG AATGTGCAGA 180CGCGAA 186 507 base pairs nucleic acid single linear DNA (genomic) unknown dpd2090 lower 14CACCAGGGCC GCCTTCACTT TCGCGGTGAT GGCGCTGTCA TCCATGAAAT TACCGACTTT 60ATTCATAGAG CTATCGACTT TTTGCCCTGC GCTTTCATTG GTAGTCTGCG CGTTGTTTTC 120CGCGTAGGCA GAGCCGGTCG CGACGGCAGA GGTCAACATT ACAGCCAGCA GAGTTTTCGA 180AATCTTCAGT CTTGTCATAG TCATCGATTT ATTCCTGTAT GTTTGCTCGT AATTTGAGCC 240TGGCAACACG AGGTTGCATT GCTGAATAGG GAGAGACTTC ACCCTCTACA GAAGTCAATG 300GTCGCCATCA CAAAAGCGAT GAGTGATGAA TAACGACCAT TACAGCCTCT GAATCAGTTA 360TTAATATCGG TAGAATGACA ATCGACGGCT TTAGATACTG ATATCTACGC ATTGAACGGT 420ATTTAACGCC GTCAGAAATG TCATCACTTT GTTAAATATA GATCACAATT TTGAAACCGC 480TCGGGATATC ACGAAACATA ACAAAAT 507 428 base pairs nucleic acid single linear DNA (genomic) unknown dpd2092 upper 15CAAGCCGGTT AACGACCTGT CCCGTGGCGC ACTGGTTGAC GATATCGTCT ACACCATCGC 60GCTGACTGCG ATTCAGTCTG CACAGCAGCA GTAATCTCGC ATCATCCGCA GCTTTGCGCT 120GCGGATATCT GAACCGGAAA TAATCACTAT TTCCGGTTTT TTATTCTCTT AATTTGCATT 180AATCCTTTCT GATTATCTTG CTTAACTGCG CTGCATCAAT GAATTGCGCC ATCCCACTTT 240GCATACTTAC CACTTTGTTT TGTGCAAGGG AATATTTGCG CTATGTCCGC AATCACTGAA 300TCCAAACCAA CAAGAAGATG GGCAATGCCC GATACGTTGG TGATTATCTT TTTTGTTGCT 360ATTTTAACCA GCCTTGCCAC CTGGGTAGTT CCGGTGGGGA TGTTTGACAG TCAGGAAGTG 420CAGTATCA 428 554 base pairs nucleic acid single linear DNA (genomic) unknown dpd2092 lower 16AGGCCAATCA GAGTGGCGAT AACCCACACC ACGATGCGCA ACCCGGAGCC AGAAAGCACC 60GGAACGCCGG CAATCCCCTG AGCAACGACC ACACAAAACG GGTTCATCCA CGAACTGGCA 120AAACCGATTT GCGTGGCAAT ATAGGTCACC AGGACGGTGG TAATACTGTC ATAGCCCAGC 180CGGACCATTA GCGGTGCGAT GATAATGGCA AAGGCGACGG CCTCTTCTCC CATACCAAAT 240ACCGCGCCGC CAAGTGAAAA CAGAATAAAC AGCGCAGGAA TAAAGAGAAT TTCATTCCCG 300CGGGTATGGC GAATAAGCGC CAGGATACCG TTATCAATGG TTCCTGTACG CATCACAATG 360CCAAACGCGC CGCCAATCAC CAGCATAAAC ATGATGATGC CAACGGCTGT CCCGTATTTC 420GATCCTGAAG TTAATCCTTC AAACGGGAAT TCATCAGCCC GGGCGTTCAT CGCCCGTCGT 480GAACAGCTGT ACGCGGTGAT ACTCAGGTTC CCTGCTTCGT AATCAAATGC AAATGATTTT 540GATCTACAAT TTGC 554 87 base pairs nucleic acid single linear DNA (genomic) unknown dpd3501 upper 17GGTCACTTAC TAGGTTATCG GGCCGGTGAT GTCCGACCTC ATGGGCGGGC TGCTCCACTT 60CCTGAATACC ATTCCTCCAT CAATGAA 87 134 base pairs nucleic acid single linear DNA (genomic) unknown dpd3501 lower 18ACGACGTCCG GTTTAATGTG TTCCGCCGAG GTTTGCGCCC CGCGTAGCCC AACTTCTTCT 60TCCACACTGC CAACGCCATA CAGCGTAATT TCGGGATTAT TCACCGTCTG CAATAGTTCA 120GCCATCATTG CGCA 134 203 base pairs nucleic acid single linear DNA (genomic) unknown dpd3505 upper 19TATGGTTTAT CGCTGGTGGG ATTCGGTCTG TTGATTTCAT CACTCTGTTC AACACAACAG 60CAGGCGTTTA TCGGCGTGTT TGTCTTTATG ATGCCCGCCA TTCTCCTTTC CGGTTACGTT 120TCTCCGGTGG AAAACATGCC GGTATGGCTG CAAAACCTGA CGTGGATTAA CCCTATTCGC 180CACTTTACGG ACATTACCAA GCA 203 410 base pairs nucleic acid single linear DNA (genomic) unknown dpd3505 lower 20CTGTCCAGTC GTAGTAGAGG AAATTGCACC GGAAACGTGC GCGCCGGGCG TCCGTGGGCG 60CGGGTAAAAA TCTCATCCAG TCCGGCCTGC ACTTTTAACG GATGATTAGC TTTTTGCCGC 120CAGTCATTGA AATCACCCGC CACCAATACC GGTTCGCCGT CCGGTAGCTC ATTCACCCAT 180TCGGCGAGCA TCGCAAGCTG CGCCTGACGG TGCGCCTCAC GCAGGCCCAG ATGTACGCAC 240ATCACATGAA TCGCTTTTCC GGTCATCGGC GGCACAATGC GGCAGTAGAG CACGCCGCGC 300TTTTCCGCAC CATCGACCGA AACATCGCGA TTCTCATAAT GTTCAATGGG ATAACGCGAC 360AGTACGGCGT TGCCGTGATG CCCTTCCGGG TATACGGCAT TGCGACCGTA 410 164 base pairs nucleic acid single linear DNA (genomic) unknown dpd3507 upper 21GCCGTTACAC ACGCTGCCAC TGGCAACCAA AGTCCCGGAA CCCTTACCGC CGCTGGAAGG 60ATACACCTTT GAGGGCTACG CAATGCCGAT GGCAGCGTGG GCACCAAAAA CCTGCTCGGT 120ATCACCACCA GCGTCCACTG TGTGGCAGGC GTGGTGGACT ATGT 164 285 base pairs nucleic acid single linear DNA (genomic) unknown dpd3507 lower 22CTCCTGTTCA TCTCCCAGTC GGCACATAAA TACTTGCCCA CCAGGCAGAA TTTCGTAATG 60AATGCTGTCC TGGCCTGGCT TCAGTTTTAA GGCCTCACGC ACTGGCGCGG GGATAGTTGT 120TTGTCCGCGT ATCGTGACCT TTGATTCAGT GGTCAGTACA GCGTGAGAGC GAGCATTAGC 180GGGCATGATT CACTGTCCTT TTACAGCCTG TTTTCTGCTC AAATTATAAG CTTGAACTAA 240GGTAATGCAA ATGCATTATT AATGGACGTG GGGGCTTTAA ACAAT 285 223 base pairs nucleic acid single linear DNA (genomic) unknown dpd3509 upper 23GATGGAGTGG CGTAACTATC CGGTAACGCT GGTGGCAGAA AATAACGTTA CCGAAGGCTT 60TATCGCTGGT CGTCTCACTC GCGAACTGCT GGCAGGTGTA CCTGACTTAG CTTCACGTAC 120CGTGATGACC TGCGGCCCGG CTCCGTATAT GGATTGGGTA GAGCAGGAAG TGAAAGCGCT 180CGGCGTGACG CGTTTCTTTA AAGAGAAATT CTTCACCCCA GTA 223 260 base pairs nucleic acid single linear DNA (genomic) unknown dpd3509 lower 24TGCTCCGGGC TGGAAACCAG CTCGCAATAG TGACTACATT CGCGGAATAG CTCTTGTGGG 60TGGGTTTCCT GGAAATAGCC GCTGCCAATT TCGCTGGAGG GAATATGAGC GGCAATCGCC 120AGTACCGGAA CGTGATTGCG GTGGCAATCG AACAGGCCGT TGATTAAGTG CAGGTTGCCG 180GGGCCGCACG ATCCGGCGCA GACCGCCAGT TCTCCGCTAA GTTGTGCTTC AGCGCCAGCG 240GCAAAGGCCG CCACTTCTTC 260 172 base pairs nucleic acid single linear DNA (genomic) unknown dpd3512 upper 25AATGGAGTTT GACTAATACA GGAATACTAT GAGTCTGAAT TTCCTTGATT TTGAACAGCC 60GATTGCAGAG CTGGAAGCGA AAATCGATTC TCTGACTGCG GTTAGCCGTC AGGATGAGAA 120ACTGGATATT AACATCGATG AAGAAGTGCA TCGTCTGCGT GAAAAAAGCG TA 172 527 base pairs nucleic acid single linear DNA (genomic) unknown dpd3512 lower 26ACTTTTCCCG CAACACGCTC GCCGCTCATA CCACTTTTAC CCTGGTAGAT CGGATGAAAA 60TGGGTGTACG GCACCCAGGC AGAATCGAAG TGAATCGACG GGACATCCAG CGTCTGTTTG 120ATCCAGTCGG TGTTGTAGAG CAAGCCATCA TAGGTGGAGT TGGTGATCAC CGCATGAACC 180GGCCATTGTG CTTGCGTGGT AGCAGCGACT TTCTCTTCGA TGCTGTCGCG AGTAAATTCA 240CGGCGCGGGA TCCCACCAAG AATCCCCAAC GCATTACGCG TCGGTTTCAG CCAGACTGGC 300ACTACATCGT TCATCATCAA CAGATGCGCC AGCGATTTAT GACAATTGCG GTCGATCAAC 360AGCGTACTGC CGGATGGCGC GGCGTACATA CCCACAATTT TGTTCGACGT CGATGTTCCG 420TTGGTAACGA TATAACTCTG TTCCGCCCAA AATCCCGCGA TTACTCTTCC GCTTCCAGTG 480TTGCCCGTGT TGTCAACAAC AACAACTCGG TGACCGAAAT AAAACTC 527 20 base pairs nucleic acid single linear DNA (genomic) unknown upper primer 27GGATCGGAAT TCCCGGGGAT 20 20 base pairs nucleic acid single linear DNA (genomic) unknown lower primer 28CTGGCCGTTA ATAATGAATG 20

Claims

1. An E. coli 1.9 kb genomic segment consisting of an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO:1 and SEQ ID NO:2.

2. An E. coli 1.4 kb genomic segment consisting of an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO:15 and SEQ ID NO:16.

3. An E. coli 1.8 genomic segment consisting of an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO:11 and SEQ ID NO:12.

4. An E. coli 1.6 kb genomic segment consisting of an SM-responsive regulatory region, said genomic segment bounded by SEQ ID NO:19 and SEQ ID NO:20.

5. A gene fusion comprising the SM-responsive regulatory region consisting of the E. coli 1.9 kb genomic segment of claim 1, the SM-responsive regulatory region operably linked to a luminescent reporter gene complex.

6. A gene fusion comprising the SM-responsive regulatory region consisting of the E. coli 1.8 kb genomic segment of claim 3, the regulatory region operably linked to a luminescent reporter gene complex.

7. A gene fusion comprising the SM-responsive regulatory region consisting of the E. coli 1.4 kb genomic segment of claim 2, the regulatory region operably linked to a luminescent reporter gene complex.

8. A gene fusion comprising the SM-responsive regulatory region consisting of the E. coli 1.7 kb genomic segment of claim 4, the regulatory region operably linked to a luminescent reporter gene complex.

9. A plasmid comprising:(i) the E. coli genomic segment of any one of claims 1, 2, 3, or 4, operably linked to a thermostable luxCDABE gene complex; and (ii) a transcription terminator region upstream of said promoter.

10. A transformant comprising a suitable host cell and the plasmid of claim 9 wherein said transformant is sensitive to SM.

11. The transformant of claim 10 wherein said suitable host cell is a bacteria classified in the Family Enterobacteriaceae.

12. The transformant of claim 11 wherein the Enteric bacteria is Escherichia coli.

13. A method to detect a crop protection chemical comprising:(i) containing a chemical compound with a detector organism containing a genomic segment comprising a responsive regulatory region operably linked to a luminescent reporter gene complex, the genomic segment selected from the group consisting of a) an E. coli 1.9 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:1 and SEQ ID NO:2; b) an E. coli 1.4 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:3 and SEQ ID NO:4; c) an E. coli 1.9 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:5 and SEQ ID NO:6; d) an E. coli 1.3 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:7 and SEQ ID NO:8; e) an E. coli 2.5 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:9 and SEQ ID NO:10; f) an E. coli 1.8 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:11 and SEQ ID NO:12; g) an E. coli 1.2 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:13 and SEQ ID NO:14; h) an E. coli 1.4 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:15 and SEQ ID NO:16; i) an E. coli 1.3 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:17 and SEQ ID NO:18; j) an E. coli 1.6 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:19 and SEQ ID NO:20; k) an E. coli 1.9 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:21 and SEQ ID NO:22; l) an E. coli 1.0 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:23 and SEQ ID NO:24; and m) an E. coli 2.0 kb genomic segment consisting of an SM-responsive regulatory region, said segment bounded by SEQ ID NO:25 and SEQ ID NO:26; and (ii) measuring an increase in bioluminescence in the detector organism, the increase in bioluminescence indicating that the chemical compound activates the responsive regulatory region and is a crop protection chemical.

14. A gene fusion comprising the SM responsive regulatory region consisting of the genomic segment bounded by SEQ ID NO:3 and SEQ ID NO:4, the regulatory region operably linked to a luminescent reporter gene complex.