AU2002313983B2 - Mutated 5-enol pyruvylshikimate-3-phosphate synthase, gene coding for said protein and transformed plants containing said gene - Google Patents

Description

1 Mutated 5-enolpyruvylshikimate-3-phosphate synthase, gene coding for this protein and transformed plants containing this gene The present invention relates to a new 5-enolpyruvylshikimate-3-phosphate synthase (or EPSPS) which displays increased tolerance with respect to herbicides which are competitive inhibitors with respect to phosphoenolpyruvate (PEP) of EPSPS activity.

This more tolerant EPSP synthase possesses at least one "threonine by isoleucine" substitution. The invention also relates to a gene coding for such a protein, to plant cells transformed by chimeric gene constructions containing this gene, to the plants regenerated from these cells and also to the plants originating from crossing using these transformed plants.

Glyphosate, sulfosate and fosametine are broad-spectrum systemic herbicides of the phosphonomethylglycine family. They act essentially as competitive inhibitors of 5-enolpyruvylshikimate-3phosphate synthase (EC 2.5.1.19) or EPSPS with respect to the PEP (phosphoenolpyruvate). After their application to the plant, they are translocated in the plant where they accumulate in the rapidly growing parts, in particular the cauline and root apices, causing damage to the point of destruction of sensitive plants.

Plastid EPSPS, the main target of these 2 products, is an enzyme of the pathway of biosynthesis of aromatic amino acids, which is encoded by one or more nuclear genes and synthesized in the form of a cytoplasmic precursor, then imported into the plastids where it accumulates in its mature form.

The tolerance of plants to glyphosate and to products of the family is obtained by stable introduction into their genome of an EPSPS gene, of plant or bacterial origin, which is mutated or otherwise in respect of the characteristics of inhibition by glyphosate of the product of this gene.

In view of the mode of action of glyphosate and the degree of tolerance to glyphosate of the product of the genes which are used, it is advantageous to be able to express the product of the translation of this gene so as enable it to be accumulated in substantial amounts in the plastids.

It is known, for example from US Patent 4,535,060, to confer on a plant a tolerance to a herbicide of the above type, especially N-phosphonomethylglycine or glyphosate, by introducing into the genome of plants a gene coding for an EPSPS carrying at least one mutation that makes this enzyme more resistant to its competitive inhibitor (glyphosate) after localization of the enzyme in the plastid compartment. These techniques, however, need to be improved in order to obtain greater reliability in the use of these plants under agricultural conditions.

I 3 In the present description, "plant" is understood to mean any differentiated multicellular organism capable of photosynthesis, and "plant cell" is understood to mean any cell originating from a plant and capable of constituting undifferentiated tissues such as calluses or differentiated tissues such as embryos or plant parts or seeds.

The subject of the present invention is the production of transformed plants having increased tolerance to herbicides of the phosphonomethylglycine family, by regeneration of cells transformed by means of new chimeric genes containing a gene for tolerance to these herbicides.

The subject of the invention is also a chimeric gene for conferring on plants increased tolerance with respect to a herbicide having EPSPS as its target, comprising, in the direction of transcription: a promoter region, optionally a transit peptide region, a sequence of a gene coding for a glyphosate tolerance enzyme and an untranslated polyadenylation signal region at the 3' end, characterized in that the glyphosate tolerance gene contains, relative to the gene from which it is derived, a "threonine 102 by isoleucine" substitution in the "aroA"(EPSPS) region. Preferably, it comprises, in addition, in the same region, a "proline 106 by serine" substitution. These substitutions can be introduced or be present in an EPSPS sequence of any 4 origin, in particular of plant, bacterial, algal or fungal origin.

The transit peptides which can be used in the transit peptide region can be, known per se, of plant origin, for example originating from maize, sunflower, pea, tobacco or the like. The first and the second transit peptide can be identical, similar or different.

They can, in addition, each comprise one or more transit peptide units according to European Patent Application EP 0 508 909. It is the role of this characteristic region to permit the release of a mature and native protein, and especially the above mutated EPSPS, with maximum efficacy in the plasmid compartment.

The promoter region of the chimeric gene according to the invention may be advantageously composed of at least one gene promoter or promoter fragment which is expressed naturally in plants (tubulin, introns, actin, histone).

The untranslated transcription termination signal region at the 3' end of the chimeric gene may be of any origin, for example of bacterial origin, such as that of the nopaline synthase gene, or of plant origin, such as that of the Arabidopsis thaliana histone H4A748 gene according to the European Patent Application (European Application 633 317).

The chimeric gene according to the invention can comprise, in addition to the essential portions above, at least one untranslated intermediate (linker) region, which can be located between the different transcribed regions described above. This intermediate region can be of any origin, for example of bacterial, viral or plant origin.

Isolation of a cDNA coding for a maize EPSPS: The different steps which led to the obtaining of maize EPSPS cDNA, whijh served as substrate for the introduction of the two mutations, are described below. All the operations described below are given by way of example, and correspond to a choice made from among the different methods available for arriving at the same result. This choice has no effect on the quality of the result, and consequently any suitable method may be used by a person skilled in the art to arrive at the same result. Most of the methods of engineering of DNA fragments are described in "Current Protocols in Molecular Biology" Volumes 1 and 2, Ausubel F.M. et al., published by Greene Publishing Associates and Wiley-Interscience (1989) (hereinafter, references to protocols described in this work will be designated "ref. CPMB"). The operations relating to DNA which were performed according to the protocols described in this work are especially the following: ligation of DNA fragments, treatment with Klenow DNA polymerase and T4 DNA polymerase, preparation of plasmid and of bacteriophage X DNA, either as a minipreparation or as a maxipreparation, and DNA and RNA analyses according to the Southern and Northern techniques, respectively. Other methods described in this work were followed, and only significant modifications or additions to these protocols have been described below.

Example 1: 1. Obtaining of an Arabidopsis thaliana EPSPS fragment a) Two 20-mer oligonucleotides of respective sequences: 5'-GCTCTGCTCATGTCTGCTCC-3' 5'-GCCCGCCCTTGACAAAGAAA-3' were synthesized from the sequence of an Arabidopsis thaliana EPSPS gene (Klee H.J. et al. (1987) Mol. Gen.

Genet., 210, 437-442). These two oligonucleotides are at positions 1523 to 1543 and 1737 to 1717, respectively, of the published sequence, and in opposite orientations.

b) Arabidopsis thaliana (var. columbia) total DNA was obtained from Clontech (catalogue reference: 6970-1).

c) 50 nanograms (ng) of DNA are mixed with 300 ng of each of the oligonucleotides and subjected to amplification cycles with a Perkin-Elmer 9600 apparatus, under the conditions of standard medium for amplification which are recommended by the supplier.

The resulting 204-bp fragment constitutes the 7 Arabidopsis thaliana EPSPS fragment.

2. Construction of a library of a cDNA from a BMS maize cell line a) 5 g of filtered cells are ground in liquid nitrogen, and the total nucleic acids are extracted according to the method described by Shure et al. with the following modifications: the pH of the lysis buffer is adjusted to pH after precipitation with isopropanol, the pellet is taken up in water and, after dissolution, adjusted to 2.5 M LiC1. After incubation for 12 h at OC, the pellet from centrifugation for min at 30,000 g at 4°C is resolubilized. The LiCI precipitation step is then repeated. The resolubilized pellet constitutes the RNA fraction of the total nucleic acids.

b) The poly(A)* RNA fraction of the RNA fraction is obtained by chromatography on an oligo(dT)cellulose column as described in "Current Protocols in Molecular Biology".

c) Synthesis of double-stranded cDNA having a synthetic EcoRI end: this is carried out according to the protocol of the supplier of the different reagents needed for this synthesis in the form of a kit: the "copy kit" from the company In Vitrogen.

Two single-stranded and partially complementary oligonucleotides of respective sequences: 5'-AATTCCCGGG-3' 5'-CCCGGG-3' (the latter being phosphorylated) are ligated with the blunt-ended double-stranded cDNAs.

This ligation of the adaptors results in the creation of SmaI sites attached to the double-stranded cDNAs and EcoRI sites in cohesive form at each end of the double-stranded cDNAs.

d) Creation of the library: The cDNAs possessing the artificial cohesive EcoRI sites at their ends are ligated with bacteriophage XgtlO cDNA which has been cut with EcoRI and dephosphorylated according to the protocol of the supplier New England Biolabs.

An aliquot of the ligation reaction was encapsidated in vitro with encapsidation extracts, namely Gigapack Gold, according to the supplier's instructions; this library was titrated using the bacterium E. coli C600hfl. The library thereby obtained is amplified and stored according to the instructions of the same supplier, and constitutes the BMS maize cell suspension cDNA library.

3. Screening of the BMS maize cell suspension cDNA library with the Arabidopsis thaliana EPSP probe The protocol followed is that of "Current Protocols in Molecular Biology" Volumes 1 and 2, 4b 9 Ausubel F.M. et al., published by Greene Publishing Associates and Wiley-Interscience (1989)(CPMB).

Briefly, approximately 106 recombinant phages are plated out on LB dishes at an average density of 100 phages/cm. The lytic plaques are replicated in duplicate on Amersham Hybond N membranes.

The DNA was fixed to the filters by 1600kJ UV treatment (Stratagene Stratalinker). The filters were prehybridized in 6xSSC/0.1%SDS/0.25 skimmed milk for 2 h at 65°C. The Arabidopsis thaliana EPSPS probe was labelled with ["P]dCTP by random priming according to the supplier's instructions (Pharmacia Ready to Go kit). The specific activity obtained is of the order of 108 cpm per pg of fragment. After denaturation for 5 min at 100 0 C, the probe is added to the prehybridization medium and hybridization is continued for 14 hours at The filters are fluorographed for 48 h at -80 0

C

with Kodak XAR5 film and Amersham Hyperscreen RPN enhancing screens. Alignment of the positive spots on the filter with the dishes from which they originate enables zones corresponding to the phages displaying a positive hybridization response with the Arabidopsis thaliana EPSPS probe to be picked out from the dish.

This step of plating out, transfer, hybridization and recovery is repeated until all the spots in the dish of the successively purified phages prove 100% positive in hybridization. An independent plaque of phage lysis is then picked out in diluent X medium (Tris-Cl pH 1 MgSO,; 0.1M NaCI; 0.1% gelatin); these phages in solution constitute the EPSP-positive clones of the BMS maize cell suspension.

4. Preparation and analysis of the DNA of the EPSP clones of the BMS maize cell suspension Approximately 5x10 8 phages are added to 20 ml of C600hfl bacteria at an OD6,oo value of 2/ml and incubated for 15 minutes at 37 0 C. This suspension is then diluted in 200 ml of bacterial growth medium in a 1-1 Erlenmeyer and stirred in a rotary stirrer at 250 rpm. Lysis is noted when the medium clarifies, corresponding to the lysis of the turbid bacteria, and takes place after approximately 4 h of stirring. This supernatant is then treated as described in "Current Protocols in Molecular Biology". The DNA obtained corresponds to the EPSP clones of the BMS maize cell suspension.

One to two fg of this DNA are cut with EcoRI and separated on 0.8% LGTA/TBE agarose gel (ref. CPMB).

A final verification consists in checking that the purified DNA does indeed display a hybridization signal with the Arabidopsis thaliana EPSPS probe. After electrophoresis, the DNA fragments are transferred onto Amersham Hybond N membranes according to the protocol of Southern described in "Current Protocols in Molecular Biology". The filter is hybridized with the Arabidopsis thaliana EPSPS probe according to the conditions described in section 3 above. The clone displaying a hybridization signal with the Arabidopsis thaliana EPSPS probe and containing the longest EcoRI fragment has a size estimated on gel as approximately 1.7 kbp.

5. Obtaining of the clone pRPA-ML-711 Ten gg of the phage clone containing the 1.7-kbp insert are digested with EcoRI and separated on 0.8% LGTA/TBE agarose gel (ref. CPMB). The gel fragment containing the 1.7-kbp insert is excised from the gel by BET staining, and the fragment is treated with -agarase according to the protocol of the supplier, New England Biolabs. The purified DNA of the 1.7-kbp fragment is ligated at 12 0 C for 14 h with the DNA of plasmid pUC 19 (New England Biolabs) cut with EcoRI according to the ligation protocol described in "Current Protocols in Molecular Biology". Two il of the above ligation mixture are used for the transformation of an aliquot of electrocompetent E. coli transformation is accomplished by electroporation using the following conditions: the mixture of competent bacteria and ligation medium is introduced into an electroporation cell of thickness 0.2 cm (Biorad) previously cooled to 0°C. The physical conditions of the electroporation using an electroporator made by Biorad are 2500 volts, 25 gF and 200 Q. Under these conditions, the mean discharge time of the condenser is of the order of 4.2 milliseconds. The bacteria are then taken up in 1 ml of SOC medium (ref. CPMB) and stirred 12 for 1 hour at 200 rpm on a rotary stirrer in Corning tubes. After plating out on LB/agar medium supplemented with 100 gg/ml of carbenicillin, minipreparations of the bacterial clones which have grown after one night at 37 0 C are produced according to the protocol described in "Current Protocols in Molecular Biology". After digestion of the DNA with EcoRI and separation by electrophoresis on 0.8% LGTA/TBE agarose gel (ref. CPMB), the clones possessing a 1.7-kbp insert are retained. A final verification consists in checking that the purified DNA does indeed display a hybridization signal with the Arabidopsis thaliana EPSPS probe. After electrophoresis, the DNA fragments are transferred onto Amersham Hybond N membranes according to the protocol of Southern described in "Current Protocols in Molecular Biology". The filter is hybridized with the Arabidopsis thaliana EPSPS probe according to the conditions described in section 3 above. The plasmid clone possessing a 1.7-kbp insert and hybridizing with the Arabidopsis thaliana EPSPS probe was prepared on a larger scale, and the DNA resulting from the lysis of the bacteria was purified on a CsCl gradient as described in "Current Protocols in Molecular Biology". The purified DNA was partially sequenced with a Pharmacia kit according to the supplier's instructions and using as primers the M13 direct and reverse universal primers ordered from the same supplier. The partial sequence produced covers approximately 0.5 kbp. The derived amino acid sequence in the region of the mature protein (approximately amino acid residues) displays 100% identity with the corresponding amino sequence of mature maize EPSPS described in American Patent USP 4,971,908. This clone, corresponding to a 1.7-kbp EcoRI fragment of the EPSP DNA of the BMS maize cell suspension, was designated pRPA-ML-711. The complete sequence of this clone was determined on both strands using the protocol of the Pharmacia kit and synthesizing complementary oligonucleotides and those of the opposite orientation every 250 bp approximately. The complete sequence obtained of this 1713-bp clone is presented in SEQ ID No. 1.

6. Obtaining of the clone pRPA-ML-715 Analysis of the sequence of the clone pRPA- ML-711, and especially comparison of the derived amino acid sequence with that of maize, shows a sequence extension of 92 bp upstream of the GCG codon coding for the NH,-terminal alanine of the mature portion of maize EPSPS (American Patent USP 4,971,908). Similarly, an extension of 288 bp downstream of the AAT codon coding for the COOH-terminal asparagine of the mature portion of maize EPSPS (American Patent USP 4,971,908) is observed. These two portions could correspond, in the case of the NH2-terminal extension to a portion of the sequence of a transit peptide for plastid localization, and, in the case of the COOH-terminal extension, to the untranslated 3' region of the cDNA.

In order to obtain a cDNA coding for the mature portion of the maize EPSPS cDNA, as described in USP 4,971,908, the following operations were carried out: a) Removal of the untranslated 3' region: construction of pRPA-ML-712: The clone pRPA-ML-711 was cut with the restriction enzyme Asel, and the ends resulting from this cleavage were rendered blunt by treatment with the Klenow fragment of DNA polymerase I according to the protocol described in CPMB. A cleavage with the restriction enzyme SacII was then performed. The DNA resulting from these operations was separated by electrophoresis on 1% LGTA/TBE agarose gel (ref. CPMB).

The gel fragment containing the 0.4-kbp "Asel-blunt ends/SacII" insert was excised from the gel and purified according to the protocol described in section 5 above. The DNA of the clone pRPA-ML-711 was cut with the restriction enzyme HindIII at the HindIII site located in the polylinker of the cloning vector pUC19, and the ends resulting from this cleavage were rendered blunt by treatment with the Klenow fragment of DNA polymerase I. A cleavage with the restriction enzyme SacII was then performed. The DNA resulting from these manipulations was separated by electrophoresis on 0.7% LGTA/TBE agarose gel (ref. CPMB).

The gel fragment containing the approximately 3.7-kbp HindIII-blunt ends/SacII insert was excised from the gel and purified according to the protocol described in section 5 above.

The two inserts were ligated, and 2 il of the ligation mixture were used to transform E. coli DH1OB as described above in section The plasmid DNA content of different clones was analysed according to the procedure described for pRPA-ML-711. One of the plasmid clones selected contains an approximately 1.45-kbp EcoRI-HindIII insert. The sequence of the terminal ends of this clone reveals that the 5' end of the insert corresponds exactly to the corresponding end of pRPA-ML-711, and that the 3'-terminal end possesses the following sequence: "5'-...AATTAAGCTCTAGAGTCGACCTGCAGGCATGCAAGCTT-3'".

The underlined sequence corresponds to the codon of the COOH-terminal amino acid asparagine, the next codon corresponding to the translation stop codon.

The nucleotides downstream correspond to sequence elements of the pUC19 polylinker. This clone comprising the pRPA-ML-711 sequence up to the translation termination site of mature maize EPSPS and followed by sequences of the pUC 19 polylinker up to the HindIII site was designated pRPA-ML-712.

b) Modification of the 5' end of pRPA-ML-712: construction of pRPA-ML-715: The clone pRPA-ML-712 was cut with the 16 restriction enzymes PstI and HindIII. The DNA resulting from these manipulations was separated by electrophoresis on 0.8% LGTA/TBE agarose gel (ref.

CPMB). The gel fragment containing the 1.3-kbp PstI- EcoRI insert was excised from the gel and purified according to the protocol described in section 5 above.

This insert was ligated in the presence of an equimolecular amount of each of the two partially complementary oligonucleotides of sequence: 01igo 1: 5'-GAGCCGAGCTCCATGGCCGGCGCCGAGGAGATCGTGCTGCA-3' Oligo 2: 5'-GCACGATCTCCTCGGCGCCGGCCATGGAGCTCGGCTC-3' as well as in the presence of plasmid pUC19 DNA digested with the restriction enzymes BamHI and HindIII.

Two jl of the ligation mixture were used to transform E. coli DH10B as described above in section After analysis of the plasmid DNA content of different clones according to the procedure described above in section 5, one of the clones possessing an approximately 1.3-kbp insert was retained for subsequent analyses. The sequence of the end of the selected clone reveals that the DNA sequence in this region is the following: sequence of the pUC19 polylinker from the EcoRI to the BamHI sites, followed by the sequence of the oligonucleotides used in the cloning, followed by the remainder of the sequence present in pRPA-ML-712. This clone was designated pRPA- ML-713. This clone possesses a methionine ATG codon included in an NcoI site upstream of the N-terminal alanine codon of mature EPSP synthase. Furthermore, the alanine and glycine codons of the N-terminal end have been preserved, but modified on the third variable base: initial GCGGGT gives modified GCCGGC.

The clone pRPA-ML-713 was cut with the restriction enzyme HindIII, and the ends of this cleavage were rendered blunt by treatment with the Klenow fragment of DNA polymerase I. A cleavage with restriction enzyme SacI was then performed. The DNA resulting from these manipulations was separated by electrophoresis on 0.8% LGTA/TBE agarose gel (ref.

CPMB). The gel fragment containing the 1.3-kbp "HindIII-blunt ends/SacI" insert was excised from the gel and purified according to the protocol described in section 5 above. This insert was ligated in the presence of plasmid pUC19 DNA digested with restriction enzyme XbaI, and the ends of this cleavage were rendered blunt by treatment with the Klenow fragment of DNA polymerase I. A cleavage with the restriction enzyme SacI was then performed. Two pl of the ligation mixture were used to transform E. coli DH10B as described above in section 5. After analysis of the plasmid DNA content of different clones according to the procedure described above in section 5, one of the clones possessing an approximately 1.3-kbp insert was retained for subsequent analyses. The sequence of the terminal ends of the selected clone reveals that the 18 DNA sequence is the following: sequence of the pUC19 polylinker from the EcoRI to SacI sites, followed by the sequence of the oligonucleotides used in the cloning from which the 4 bp GATCC of the oligonucleotide 1 described above have been deleted, followed by the remainder of the sequence present in pRPA-ML-712 up to the HindIII site and sequence of the pUC19 polylinker from XbaI to HindII. This clone was designated pRPA-ML-715.

7. Obtaining of-a cDNA coding for a mutated maize EPSPS All the mutagenesis steps were carried out with the Pharmacia U.S.E. mutagenesis kit according to the supplier's instructions. The principle of this mutagenesis system is as follows: plasmid DNA is denatured by heat and reassociated in the presence of a molar excess of, on the one hand the mutagenesis oligonucleotide, and on the other hand an oligonucleotide enabling a unique restriction enzyme site present in the polylinker to be eliminated. After the reassociation step, synthesis of the complementary strand is carried out by the action of T4 DNA polymerase in the presence of T4 DNA ligase and gene 32 protein in a suitable buffer which is supplied. The synthesis product is incubated in the presence of the restriction enzyme for which the site is assumed to have disappeared by mutagenesis. The E. coli strain possessing, in particular, the mutS mutation is used as host for the transformation of this DNA. After growth in liquid medium, the total plasmid DNA is prepared and incubated in the presence of the restriction enzyme used before. After these treatments, E. coli strain DH1OB is used as host for the transformation. The plasmid DNA of the clones isolated is prepared, and the presence of the mutation introduced is verified by sequencing.

modification of sites or sequences without in principle affecting the EPSPS-resistance character of maize to products which are competitive inhibitors of EPSP synthase activity: elimination of an internal NcoI site from pRPA-ML-715.

The pRPA-ML-715 sequence is numbered arbitrarily by placing the first base of the N-terminal alanine codon GCC at position 1. This sequence possesses an NcoI site at position 1217. The sitemodification oligonucleotide possesses the sequence: 5'-CCACAGGATGGCGATGGCCTTCTCC-3'.

After sequencing according to the references given above, the sequence read after mutagenesis corresponds to that of the oligonucleotide used. The NcoI site has indeed been eliminated, and the translation into amino acids in this region preserves the initial sequence present in pRPA-ML-715.

This clone was designated pRPA-ML-716.

The 1340-bp sequence of this clone is presented in SEQ ID No. 2 and SEQ ID No. 3.

sequence modifications enabling the EPSPS-resistance character of maize to products which are competitive inhibitors of EPSP synthase activity to be increased.

The following oligonucleotides were used: a) mutation Thr 102 Ile.

5'-GAATGCTGGAATCGCAATGCGGCCATTGACAGC-3' b) mutation Pro 106 Ser.

5'-GAATGCTGGAACTGCAATGCGGTCCTTGACAGC-3' c) mutations Gly 101 Ala and Thr 102 lie.

5'-CTTGGGGAATGCTGCCATCGCAATGCGGCCATTG-3' d) mutations Thr 102 Ile and Pro 106 Ser.

5'-GGGGAATGCTGGAATCGCAATGCGGTCCTTGACAGC-3' After sequencing, the sequence read after mutagenesis on the three mutated fragments is identical to the parent pRPA-ML-716 DNA sequence, with the exception of the mutagenized region which corresponds to that of the mutagenesis oligonucleotides used. These clones were designated: pRPA-ML-717 for the mutation Thr 102 Ile, pRPA-ML-718 for the mutation Pro 106 Ser, pRPA-ML-719 for the mutations Gly 101 Ala and Thr 102 Ile and pRPA-ML-720 for the mutations Thr 102 Ile and Pro 106 Ser.

The 1340-bp sequence of pRPA-ML-720 is presented in SEQ ID No. 4 and SEQ ID No. The 1395-bp NcoI-HindIII insert is the basis of all the constructions used for the transformation of plants for the introduction of resistance to herbicides which are competitive inhibitors of EPSPS, and especially glyphosate resistance. This insert will be designated in the remainder of the description "the maize EPSPS double mutant".

Example 2: Glyphosate tolerance of the different mutants in vitro 2.a: Extraction of EPSP synthase The different EPSP synthase genes are introduced in the form of an NcoI-HindIII cassette into the plasmid vector pTrc99a (Pharmacia, ref: 27-5007-01) cut with NcoI and HindIII. Recombinant E. coli DH1OB bacteria overexpressing the different EPSP synthases are sonicated in 40 ml of buffer per 10 g of pelleted cells, and washed with this same buffer (200 mM Tris- HC1 pH 7.8, 50 mM mercaptoethanol, 5 mM EDTA and 1 mM PMSF), to which 1 g of polyvinylpyrrolidone is added.

The suspension is stirred for 15 minutes at 4 0 C and then centrifuged for 20 minutes at 27,000 g and 4°C.

Ammonium sulphate is added to the supernatant to bring the solution to 40% saturation with respect to ammonium sulphate. The mixture is centrifuged for minutes at 27,000 g and 4 0 C. Ammonium sulphate is added to the new supernatant to bring the solution to saturation with respect to ammonium sulphate. The mixture is centrifuged for 30 minutes at 27,000 g and 4°C. The EPSP synthase present in this protein pellet is taken up in 1 ml of buffer (20 mM Tris-HCl pH 7.8 and 50 mM mercaptoethanol). This solution is dialysed overnight against two litres of this same buffer at 4 0

C.

2.b: Enzyme activity The activity of each enzyme, as well as its glyphosate resistance, is measured in vitro over minutes at 37 0 C in the following reaction mixture: 100 mM maleic acid pH 5.6, 1 mM phosphoenolpyruvate, 3 mM shikimate 3-phosphate (prepared according to Knowles P.F. and Sprinson D.B. 1970. Methods in Enzymol 17A, 351-352 from Aerobacter aerogenes strain ATCC 25597) and 10 mM potassium fluoride. The enzyme extract is added at the last moment after the addition of glyphosate, the final concentration of which varies from 0 to 20 mM.

The activity is measured by assaying the phosphate liberated according to the technique of Tausky H.A. and Shorr E. 1953. J. Biol. Chem. 202, 675- 685.

Under these conditions, the wild-type (WT) enzyme is already 85% inhibited at a glyphosate concentration of 0.12 mM. At this concentration, the mutant enzyme known as Serl06 is only 50% inhibited, and the other three mutants, Ilel02, Ilel02/Serl06 and 23 Alal01/Ilel02, show little or no inhibition.

The glyphosate concentration has to be multiplied by ten, that is to say 1.2 mM, in order to produce a 50% inhibition of the mutant enzyme Ilel02, the mutants Ile102/Serl06, Ala/Ile and Ala still not being inhibited.

It should be noted that the activity of the mutants Ala/Ile and Ala is not inhibited up to glyphosate concentrations of 10mM, and that that of the mutant Ilel02/Serl06 is not reduced even if the glyphosate concentration is multiplied by 2, that is to say 20 mM.

Example 3: Resistance of transformed tobacco plants 1-1- Transformation The vector pRPA-RD-173 is introduced into Agrobacterium tumefaciens strain EHA101 (Hood et al., 1987) carrying the cosmid pTVK291 (Komari et al., 1986). The transformation technique is based on the procedure of Horsh et al. (1985).

1-2- Regeneration The regeneration of PBD6 tobacco (source SEITA France) from leaf explants is carried out on a Murashige and Skoog (MS) basal medium comprising 30 g/l of sucrose as well as 200 gg/ml of kanamycin. The leaf explants are removed from plants cultivated in the greenhouse or in vitro and are transformed according to the leaf disc technique (Science, 1985, Vol. 227, pp.

24 1229-1231) in three successive steps: the first comprises the induction of shoots on a medium supplemented with 30 g/l of sucrose containing 0.05 mg/1 of naphthylacetic acid (NAA) and 2 mg/l of benzylaminopurine (BAP) for 15 days. The shoots formed during this step are then developed for 10 days by culturing on an MS medium supplemented with 30 g/1 of sucrose but not containing any hormone. Shoots which have developed are then removed and cultured on an MS rooting medium having half the content of salts, vitamins and sugar and not containing any hormone.

After approximately 15 days, the rooted shoots are transferred to soil.

1-3- Glyphosate resistance Twenty transformed plants were regenerated and transferred to the greenhouse for the construction of pRPA-RD-173. These plants were treated in the greenhouse at the 5-leaf stage with an aqueous suspension of RoundUp corresponding to 0.8 kg of glyphosate active substance per hectare.

The results correspond to the observation of phytotoxicity indices recorded 3 weeks after treatment.

Under these conditions, it is found that the plants transformed with the construction pRPA-RD-173 display very good tolerance, whereas the untransformed control plants are completely destroyed.

These results show clearly the improvement brought about by the use of a chimeric gene according to the invention for the same gene coding for glyphosate tolerance.

Example 4: Transformation and selection of maize cells BMS (Black Mexican Sweet) maize cells in an exponential growth phase are bombarded with the construction pRPA-RD-130 according to the principle and the protocol described by Klein et al. 1987 (Klein Wolf Wu R. and Sandford J.C. (1987): High velocity microprojectiles for delivering nucleic acids into living cells, NATURE Vol. 327 pp. 70-73).

Two days after bombardment, the cells are transferred to the same medium containing 2 mM N-(phosphonomethyl)glycine.

After 8 weeks of selection on this medium, calluses which develop are selected, then amplified and analysed by PCR, and reveal clearly the presence of the chimeric OTP-EPSPS gene.

Cells not bombarded and grown on the same medium containing 2 mM N-(phosphonomethyl)glycine are blocked by the herbicide and do not develop.

The transformed plants according to the invention may be used as parents for obtaining lines and hybrids having the phenotypic character corresponding to the expression of the chimeric gene introduced.

Description of the constructions of the plasmids pRPA-RD-124: Addition of a "nos" polyadenylation signal to pRPA-ML-720 with creation of a cloning cassette containing the maize double mutant EPSPS gene (Thr 102 Ile and Pro 106 Ser). pRPA-ML- 720 is digested with HindIII and treated with the Klenow fragment of E. coli DNA polymerase I to produce a blunt end. A second digestion is performed with NcoI, and the EPSPS fragment is purified. The EPSPS gene is then ligated with purified pRPA-RD-12 (a cloning cassette containing the polyadenylation signal of nopaline synthase) to give pRPA-RD-124. To obtain the useful purified vector pRPA-RD-12, it was necessary for the latter to be digested beforehand with SalI, treated with Klenow DNA polymerase and then digested a second time with NcoI.

pRPA-RD-125: Addition of an optimized transit peptide (OTP) to pRPA-RD-124 with creation of a cloning cassette containing the EPSPS gene targeted on the plasmids. pRPA-RD-7 (European Patent Application EP 652 286) is digested with SphI, treated with T4 DNA polymerase and then digested with Spel, and the OTP fragment is purified. This OTP fragment is cloned into pRPA-RD-124 which has previously been digested with NcoI, treated with Klenow DNA polymerase to remove the protruding 3' portion and then digested with Spel. This clone is then sequenced in order to ensure correct translational fusion between the OTP and the EPSPS gene. pRPA-RD-125 is then obtained.

pRPA-RD-130: Addition of the H3C4 maize histone promoter and of adhl intron 1 sequences of pRPA-RD-123 (Patent Application EP 507 698) to pRPA-RD- 125 with creation of a cassette for expression in plants for the expression of the double mutant EPSPS gene in the tissues of monocotyledons. pRPA-RD-123 (a cassette containing the H3C4 maize histone promoter fused with the adhl intron 1) is digested with NcoI and SacI. The DNA fragment containing the promoter derived from pRPA-RD-123 is then purified and ligated with pRPA-RD-125 which has previously been digested with NcoI and SacI.

pRPA-RD-159: Addition of the H4A748 Arabidopsis histone double promoter (Patent Application EP 507 698) to pRPA-RD-125 with creation of a cassette for expression in plants for the expression of the "OTP-double mutant EPSPS gene" gene in the tissues of dicotyledons. pRPA-RD-132 (a cassette containing the H4A748 double promoter (Patent Application EP 507 698)) is digested with NcoI and SacI. The purified promoter fragment is then cloned into pRPA-RD-125 which has been digested with Ecol and SacI.

pRPA-RD-173: Addition of the "H4A748 promoter-0TP-double mutant EPSPS gene" gene of pRPA-RD- 159 to plasmid pRPA-BL-150A (European Patent Application 508 909) with creation of an Agrobacterium 05-06-'06 12:36 FROM- T-828 P007/015 F-728 0 -28ci tuimefaciens transformation vector. pRPA-RD-159 is digested n with NotI and treated with Klenow polymerase. This fragment o is then cloned into pRPA-BL-150A with SmaI.

Throughout this specification and the claims which 00 Sfollow, unless the context requires otherwise, the word "comprise", and or variations such as "comprises" or Ci- "comprising", will be understood to imply the inclusion of a o stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

COMS ID No: SBMI-03791700 Received by IP Australia: Time 12:42 Date 2006-06-05

Claims (8)

1. 05-06-'06 12:36 FROM- T-828 P008/015 F-728 ~-37- ^0 0 ci STHE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A transformed plant with improved tolerance to o phosphomethylglycine family herbicides, which plant is obtained by regeneration of transformed cells containing a chimeric gene which comprises, 00 0in the direction of transcription, a promoter -region composed of at least one promoter or c-i promoter fragment of a gene which is expressed 0 o naturally in plants, a transit peptide region which allows the targeting of a mature protein into the plastidic compartment, a sequence of a gene coding for a glyphosate tolerance enzyme, and a 3'-untranslated transcription termination signal region, characterized in that the glyphosate tolerance enzyme is a mutated 6-enolpyruvyl- shikimate-3-phosphate synthase (EPSPS) which originates from plants and comprises at least one substitution of threonine by isoleucine at the threonine which corresponds to position 102 of the maize EPSPS sequence, and one substitution of proline by serine at the proline which corresponds to position 106 of the maize EPSPS sequence. 2. A plant according to Claim 1, characterized in that the EPSPS originates from maize. 3. A plant according to Claim 2, characterized in that the EPSPS comprises the peptide sequence shown in SEQ ID NO 4. A plant according to Claim 3, characterized in that the sequence of a gene which codes for a COMS ID No: SBMI-03791700 Received by IP Australia: Time 12:42 Date 2006-06-05 05-06-'6 12:36 FROM- T-828 P09/015 F-728 PMPER a.~±(12H31Mltz ntMc i
2. 8-38- Sglyphosate tolerance enzyme comprises the coding Ssegment of the DNA sequence shown in SEQ ID NO 4. A plant according to any one of Claims 1 to 4, 5 characterized in that the promoter region 0 Scomprises a plant virus promoter. C 6. A plant according to any one of Claims 1 to o characterized in that the promoter region comprises a plant promoter. 7. A plant according to any one of Claims 1 to 6, characterized in that the promoter region comprises a fragment of a promoter of a gene which is expressed naturally in plants. 8. A plant according to Claim 7, characterized in that the fragment of a promoter which is expressed naturally in plants is an actin intron.
3. 9. A plant according to any one of Claims 1 to 8, characterized in that the transit peptide region comprises one or more transit peptide units.
4. 10. A plant according to any one of Claims 1 to 9, characterized in that the 3'-untranslated transcription termination signal region is selected from that of the nopalin synthase gene or that of the Arabidopsis thaliana histone gene H4A748. COMS ID No: SBMI-03791700 Received by IP Australia: Time 12:42 Date 2006-06-05 05-06-'06 12:37 FROM- T-828 P010/015 F-728 P;bMiAJI]ll 1393 lIUmdc..OSiMO o -39-
5. 11. A method of producing a plant with an improved tolerance to a herbicide which has EPSP synthase O as its target, characterized in that plant cells or protoplasts are transformed with a gene defined n 5 as in any one of Claims 1 to 10 and in that the 00 transformed cells are regenerated. Ce Ce 12. Plant with improved tolerance to Sphosphomethylglycine family herbicides, c 10 characterized in that it is obtained from crossing using a transformed plant according to any one of Claims 1 to 10 or a plant obtained by the method of Claim 11, which plant is composed of cells comprising a chimeric gene which comprises, in the direction of transcription, a promoter region composed of at least one promoter or promoter fragment of a gene which is expressed naturally in plants, a transit peptide region which allows the targeting of a mature protein into the plastidic compartment, a sequence of a gene coding for a glyphosate tolerance enzyme, and a 3'-untranslated transcription termination signal region, characterized in that the glyphosate tolerance enzyme is a mutated 5-enolpyruvyl-shikimate-3- phosphate synthase (EPSPS) which originates from plants and comprises at least one substitution of threonine by isoleucine at the threonine which corresponds to position 102 of the maize EPSPS sequence, and one substitution of proline by serine at the proline which corresponds to position 106 of the maize EPSPS sequence. COMS ID No: SBMI-03791700 Received by IP Australia: Time 12:42 Date 2006-06-05 05-06-'06 12:37 FROM- T-828 P011/015 F-728 0 0
6. 13. A method of treating a plant with a herbicide which V targets EPSPS, characterized in that the herbicide o is applied to plants according to any one of Claims 1 to 10 or 12 or a plant obtained by the method of Claim 11. 00
7. 14. A method according to Claim 13, characterized in Ci| that the herbicide is glyphosate or a glyphosate 010 o precursor. C N I 1 A plant according to any one of Claims 1 to 10 or Claim 12, or a method according to Claim 11, Claim 13 or Claim 14, substantially as herein described with reference to the Examples. Dated this 5 th day of June 2006. Rhone-Poulenc Agro By its Patent Attorneys, Davies Collison Cave COMS ID No: SBMI-03791700 Received by IP Australia: Time 12:42 Date 2006-06-05 P 'OPER'JMS'EPSPSq Ixl-I)llMl -29- SEQUENCE LISTING GENERAL INFORMATION: APPLICANT: Rhone-Poulenc Agro (ii) TITLE OF INVENTION: Mutated 5-enol pyruvylshikimate-3-phosphate synthase, gene coding for said protein and transformed plants containing said gene (iii) NUMBER OF SEQUENCES: (iv) CORRESPONDENCE ADDRESS: ADDRESSEE: Davies Collison Cave STREET: 1 Little Collins Street CITY: Melbourne, Victoria COUNTRY: Australia ZIP: 3000 COMPUTER READABLE FORM: MEDIUM TYPE: Floppy disk COMPUTER: IBM PC compatible OPERATING SYSTEM: PC-DOS/MS-DOS SOFTWARE: PatentIn Release Version #1.25 (vi) CURRENT APPLICATION DATA: APPLICATION NUMBER: 32558/00 FILING DATE: 5 May 2000 (viii) ATTORNEY/AGENT INFORMATION: NAME: Slattery, John M. (ix) TELECOMMUNICATION INFORMATION: TELEPHONE: (03) 9254 2777 TELEFAX: (03) 9254 2770 INFORMATION FOR SEQ ID NO:1: SEQUENCE CHARACTERISTICS: LENGTH: 1713 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (vi) ORIGINAL SOURCE: ORGANISM: Zea mays STRAIN: Black Mexican Sweet TISSUE TYPE: Callus (vii) IMMEDIATE SOURCE: LIBRARY: lambda gtlO CLONE: pRPA-ML-711 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: AATCAATTTC ACACAGGAAA CAGCTATGAC CATGATTACG AATTCGGGCC CGGGCGCGTG ATCCGGCGGC GGCAGCGGCG GCGGCGGTGC AGGCGGGTGC CGAGGAGATC GTGCTGCAGC 120 CCATCAAGGA GATCTCCGGC ACCGTCAAGC TGCCGGGGTC CAAGTCGCTT TCCAACCGGA 180 P \0PERVMS\EPSS..m.1.UA)XA) 30 TCCTCCTACT AGGATGTCCA AAGCTGCCAA AAGAGGAAGT CTGTTACTGC AGAGACCCAT TCCTTGGCAC AGGTCAAGCT CTTTGGCTCT TCGAAATGAC GGGACAGATT AAGGTGATGC TGACTGTGGA TGGAGATGAT CGCGGGAGCC CTGATGTCGC GAGACGTGGC TAACCAAGCT AGAAGCTGAA CCCTTGCCGC CCTTCCCCGA ACTACCACGC CTGTTTTTCT TTTCTATTTC GTTGGAATAA CGCCGCCCTG CTACATGCTC AAGAGCTGTA GCAGCTCTTC TGCTGGTGGA TGGCGACTTG TGACTGCCCA GTCTGGCTCC TGGGGATGTG ATTGAGATTG CTACATTAAG CTCAAGCGCA AGGTTGTGGC GGGAGCGAAG ATTTGGGAGG CATGACTCTT TTCCTGGAGA GGGAGCATCT CGTGACGGCG CTGTGCCGAG CTACTTCGAT AGCTTGATTG CTTTCACGGG GGATCTTAAG TAAGAATAAT TCCGAGGGGA GGGGCCTTGA GTTGTTGGCT TTGGGGAATG AATGCAACTT GTTGTCGGAT CCTGTTCGT G ATCAGCAGTC GAGATTGAAA ATGGAGCGTT GGAGGTCAAA AGCTATTTCT ACCACCAGTT GTTACATGGA AAACACCTCA GCTGTGGTTG GTAAAGGAGA GTTGAGGP.AG ATCGACACGT GTCCCCGTCA GTGCTGAGCA AAGTGATAGG ATTAAGTTTT TTTGTGCACT AAATTACGTT CAACAGTGGT GGACTCTTGG GTGGTGGAkA CTGGAACTGC ACGTGCTTGA TGAAGCAGCT TCAATGGAAT AGTACTTGAG TCATTGATAA TTGGTGTGAA AATACAAGTC TGGCTGGTGC TGCAGGGTGA CCGAGACTAG AGGCGATTGA CCCTCTTTGC CCGAGAGGAT GGCCGGACTA ACGACGACCA CCATCCGGGA CTTTCGTCAA CTTGTGCTGA GAGTCTGTAA GTAAGCCAAA TCAGTGAAAA TTC TGATAACCTG TCTCTCTGTC GTTCCCAGTT AATGCGGCCA TGGAGTACCA TGGTGCAGAT CGGAGGGCTA TGCCTTGCTG ATTAATCTCC AGCAGAGCAT CCCTAAAAAT TGCAATTACT TGTGAAGTTT CGTAACTGTT TGTCAACATG CGATGGCCCG GGTTGCGATC CTGCATCATC CAGGATGGCC CCCTGGGTGC GAATTAATAA GGAAATACAT CGTTAGTTGT TTTCATTTCA CTGAACAGTG GAAGCGGACA GAGGATGCTA TTGACAGCAG AGAATGAGGG GTTGATTGTT CCTGGTGGCA ATGGCTGCTC ATTCCGTACG TCTGATAGCT GCCTATGTTG GGAGGGACTG GCTGAGGTAC ACTGGCCCAC AACAAGATGC ACAGCCATCA CGGACGGAGC ACGCCGCCGG ATGGCCTTCT ACCCGGAAGA AGCGTGCGAT TTCTTTTGTT TTGTAGCAAG AGAGTGGTTC 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140 1200 1260 1320 1380 1440 1500 1560 1620 1680 1713 AAAAAAAAAA AAAAAAAAAA AACCCGGGAA INFORMATION FOR SEQ ID NO:2: SEQUENCE CHARACTERISTICS: LENGTH: 1340 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (vi) ORIGINAL SOURCE: ORGANISM: Zea mays STRAIN: Black Mexican Sweet P.'OPEMS\PSPS-" -1Ao 1 M
8. 31- (vii) IMMEDIATE SOURCE: CLONE: pRPA-ML-716 (ix) FEATURE: NAME/KEY: CDS LOCATION: 1337 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: CCATG GCC GGC GCC GAG GAG ATC GTG CTG CAG CCC ATC AAG GAG ATC Ala Gly Ala Giu Giu Ile Val Leu Gin Pro Ile Lys Giu Ile 1 5 TCC GGC ACC GTC AAG CTG CCG GGG TCC AAG TCG CTT TCC AAC CGG ATC Se r CTC Leu CTG Leu GGT Gly GGC Gly CTC Leu GTT Val1 AGA Arg CTT Leu CGT Arg GGC Gi y 175 TTG Leu Ser Leu Ser Asn Arg AlT CCG TAC GTC GAA ATG ACA TTG AGA TTG ATG GAG CGT TTT GGT GTG Ile Pro Tyr Giu Met Thr Leu Leu Met Giu Arg Phe Gly Val 220 P:\OPERUMSS\EPSPS-.tx,- ITOuM -32- AAA GCA GAG CAT TCT GAT AGC TGG GAC AGA TTC TAC ATT AAG GGA GGT Lys Ala Glu His Ser Asp Ser Trp Asp Arg Phe Tyr Ile Lys Gly Gly 225 230 235 CAA AAA TAC AAG TCC CCT AAA AAT GCC TAT GTT GAA GGT GAT GCC TCA Gin Lys Tyr Lys Ser Pro Lys Asn Ala Tyr Val Glu Gly Asp Ala Ser GCA AGC TAT TTC Ala Ser Tyr Phe GCT GGT GCT Ala Gly Ala GCA ATT ACT GGA GGG ACT GTG Ala Ile Thr Gly Gly Thr Val 265 270 ACT GTG GAA GGT Thr Val Glu Gly GGC ACC ACC AGT Gly Thr Thr Ser CAG GGT GAT GTG Gin Gly Asp Val AAG TTT Lys Phe 285 GCT GAG GTA Ala Glu Val AGC GTA ACT Ser Val Thr 305 GAG ATG ATG GGA Glu Met Met Gly AAG GTT ACA TGG Lys Val Thr Trp ACC GAG ACT Thr Glu Thr 300 AGG AAA CAC Arg Lys His GTT ACT GGC CCA Val Thr Gly Pro CGG GAG CCA TTT Arg Glu Pro Phe CTC AAG Leu Lys 320 GCG ATT GAT GTC Ala Ile Asp Val ATG AAC AAG ATG Met Asn Lys Met GAT GTC GCC ATG Asp Val Ala Met CTT GCT GTG GTT Leu Ala Val Val CTC TTT GCC GAT Leu Phe Ala Asp CCG ACA GCC ATC Pro Thr Ala Ile GAC GTG GCT TCC Asp Val Ala Ser AGA GTA AAG GAG Arg Val Lys Glu GAG AGG ATG GTT Glu Arg Met Val GCG ATC Ala Ile 365 CGG ACG GAG Arg Thr Glu TAC TGC ATC Tyr Cys Ile 385 ACC AAG CTG GGA Thr Lys Leu Gly TCT GTT GAG GAA Ser Val Glu Glu GGG CCG GAC Gly Pro Asp 380 GCG ATC GAC Ala Ile Asp ATC ACG CCG CCG Ile Thr Pro Pro AAG CTG AAC GTG Lys Leu Asn Val 1007 1055 1103 1151 1199 1247 1295 1337 1340 ACG TAC Thr Tyr 400 GAC GAC CAC AGG Asp Asp His Arg GCC ATG GCC TTC Ala Met Ala Phe CTT GCC GCC TGT Leu Ala Ala Cys GAG GTC CCC GTC Glu Val Pro Val ATC CGG GAC CCT Ile Arg Asp Pro GGG TGC ACC CGG AAG ACC Gly Cys Thr Arg Lys Thr 425 430 TTC CCC GAC TAC Phe Pro Asp Tyr TTC GAT GTG CTG AGC ACT TTC GTC AAG AAT Phe Asp Val Leu Ser Thr Phe Val Lys Asn 435 440 TAA INFORMATION FOR SEQ ID NO:3: SEQUENCE CHARACTERISTICS: LENGTH: 444 amino acids TYPE: amino acid TOPOLOGY: linear P:'OPEW\MS EPSI'S-sq ixt I ()AIRX) -33 (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID Ala Gly Ala Glu Glu Ile Val Leu Gin Pro 1 5 10 Thr Val Lys Leu Pro Gly Ser Lys Ser Leu 25 NO: 3: Ile Lys Giu Ser Asn Arg Ile Ser Gly Ile Leu Leu Leu Aia Aia Leu Ser Giu Gly Thr Thr Val Vai Asp Asn Leu Leu Asn Ser Ser Giy Leu Aila Arg Ala 145 Asn Ile Leu Tyr Giu 225 Tyr Ser Giu Val1 Thr 305 Al a Giu Val1 Giy Giy Ala Giu 130 Asp Giy Ser Gi y Vali 210 His Lys Tyr Gly Leu 290 Val1 Ile Asp Glu Lys Asn Gi y 115 Arg Val1 Ile Se r Asp 195 Glu Se r Se r Phe Cys 275 Glu Th r Asp Val1 Ala Phe Al a 100 Gi y Pro Asp Gly Gin 180 Val1 Met Asp Pro Leu 260 Gi y Met Gi y Val1 His Asp Pro Gi y As n Ile Cys Gly 165 Tyr Glu Thr Ser Lys 245 Ala Thr Met Pro Asn 1 325 40 eu Gly Tyr Met L 55 Ala Ala Giu Asp Ala Met Thr Tyr 120 Asp Leu 135 Leu Gly Pro Gly Ser Ala Giu Ile 200 Arg Leu 215 Asp Arg Ala Tyr Ala Ala Ser Leu 280 Ala Lys 295 Arg Giu Asn Lys Al a Arq Lys 90 Pro Le u Val1 Asp Lys 170 Leu Asp Glu Tyr Giu 250 Thr Gly Th r Phe Pro 330 Leu Arg Thr Leu Gly Leu Ala 75 Glu Leu Asp Gi y Cys 155 Val1 Met Lys Arg Ile 235 Gi y Gi y Asp T rp Gly 315 Asp Val1 Glu Th r GI y Leu 140 Pro Lys Ala Leu Phe 220 Lys Asp Gly Val1 Thr 300 Arg Val1 Gly Cys Leu Phe Val Thr Arg Met Leu Gly Arg Val 160 Gly Ser 175 Leu Ala Ile Pro Lys Ala Gin Lys 240 Ser Ala 255 Thr Val Ala Glu Ser Val Leu Lys 320 Thr Leu 335 P:\OPERUMS\EPSS-.txl.l WI) -34- Ala Val Val Ala Leu Phe Ala Asp Gly Pro Thr Ala Ile Arg Asp Val 340 345 350 Ala Ser Trp Arg Val Lys Glu Thr Glu Arg Met Val Ala Ile Arg Thr 355 360 365 Glu Leu Thr Lys Leu Gly Ala Ser Val Glu Glu Gly Pro Asp Tyr Cys 370 375 380 Ile Ile Thr Pro Pro Glu Lys Leu Asn Val Thr Ala Ile Asp Thr Tyr 385 390 395 400 Asp Asp His Arg Met Ala Met Ala Phe Ser Leu Ala Ala Cys Ala Glu 405 410 415 Val Pro Val Thr Ile Arg Asp Pro Gly Cys Thr Arg Lys Thr Phe Pro 420 425 430 Asp Tyr Phe Asp Val Leu Ser Thr Phe Val Lys Asn 435 440 INFORMATION FOR SEQ ID NO:4: SEQUENCE CHARACTERISTICS: LENGTH: 1340 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (vi) ORIGINAL SOURCE: ORGANISM: Zea mays STRAIN: Black Mexican Sweet (vii) IMMEDIATE SOURCE: CLONE: pRPA-ML-720 (ix) FEATURE: NAME/KEY: CDS LOCATION: 6..1337 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: CCATG GCC GGC GCC GAG GAG ATC GTG CTG CAG CCC ATC AAG GAG ATC 47 Ala Gly Ala Glu Glu Ile Val Leu Gin Pro Ile Lys Glu Ile 1 5 TCC GGC ACC GTC AAG CTG CCG GGG TCC AAG TCG CTT TCC AAC CGG ATC Ser Gly Thr Val Lys Leu Pro Gly Ser Lys Ser Leu Ser Asn Arg Ile 20 25 CTC CTA CTC GCC GCC CTG TCC GAG GGG ACA ACA GTG GTT GAT AAC CTG 143 Leu Leu Leu Ala Ala Leu Ser Glu Gly Thr Thr Val Val Asp Asn Leu 40 CTG AAC AGT GAG GAT GTC CAC TAC ATG CTC GGG GCC TTG AGG ACT CTT 191 Leu Asn Ser Glu Asp Val His Tyr Met Leu Gly Ala Leu Arg Thr Leu 55 GGT CTC TCT GTC GAA GCG GAC AAA GCT GCC AAA AGA GCT GTA GTT GTT 239 Gly Leu Ser Val Glu Ala Asp Lys Ala Ala Lys Arg Ala Val Val Val 70 P OPERJMSEPSPS.Ia 1 Ist.-WAPMA) GGC TGT GGT GGA Gly Cys Gly Gly AAG TTC GCA GTT GAG GAT GCT AAA GAG GAA GTG CAG Lys Phe Pro Val Glu Asp Ala Lys Glu Glu Val Gin TTC TTG GGG AAT Phe Leu Gly Asn GGA ATC GCA Gly Ile Ala ATG CGG Met Arg 105 TAC GTG Tyr Val 120 TCC TTG ACA GCA GCT Ser Leu Thr Ala Ala 110 CTT GAT GGA OTA CCA Leu Asp Gly Val Pro 125 GTT ACT GCT GCT GGT GGA AAT GCA ACT Val Thr Ala Ala Gly Gly Asn Ala Thr AGA ATG AGG Arg Met Arg CTT GGT GCA Leu Gly Ala 145 GAG AGA CCC ATT GGC GAC TTG GTT GTC GGA TTG AAG CAG Glu Arg Pro Ile Gly Asp Leu Val Val Gly Leu Lys Gin 130 135 140 GAT GTT GAT TGT Asp Val Asp Cys CTT GGC AC I GAG TGC CCA CCT GTT Leu Gly Thr Asp Cys Pro Pro Val 155 CGT GTC Arg Val 160 AAT GGA ATG GGA Asn Gly Ile Gly CTA GCT GGT GGG Leu Pro Gly Gly GTG AAG GTG TCT Val Lys Leu Ser GGG TCG ATC AGC AGT Gly Ser Ile Ser Ser 175 TAG TTG AGT GCG TTG GTG ATG GCT GCT Tyr Leu Ser Ala Leu Leu Met Ala Ala 185 GCT 575 Pro 190 TTG GGT GTT GGG Leu Ala Leu Gly GTG GAG ATT GAA Val Giu Ile Glu ATT GAT AAA TTA Ile Asp Lys Leu ATC TCC Ile Ser 205 ATT CCG TAG Ile Pro Tyr AAA GCA GAG Lys Ala Glu 225 GAA ATG ACA TTG Glu Met Thr Leu TTG ATG GAG GGT Leu Met Giu Arg TTT GGT GTG Phe Gly Val 220 GAT TCT GAT AGG His Ser Asp Ser GAG AGA TTG TAG ATT AAG GGA GGT Asp Arg Phe Tyr Ile Lys Gly Gly 235 CAA AAA Gin Lys 240 TAG AAG TCC CCT Tyr Lys Ser Pro AAT GCG TAT GTT Asn Ala Tyr Val GAA GGT Glu Gly 250 GAT GGC TCA Asp Ala Ser GCA AGG TAT TTC Ala Ser Tyr Phe GCT GGT GCT GCA Ala Gly Ala Ala ACT GGA GGG ACT Thr Gly Gly Thr ACT GTG GAA GGT Thr Val Giu Gly GGG ACC ACC AGT Gly Thr Thr Ser GAG GGT GAT GTG Gin Gly Asp Val AAG TTT Lys Phe 285 GCT GAG GTA Ala Glu Val AGG GTA ACT Ser Val Thr 305 GAG ATG ATG GGA Glu Met Met Gly AAG GTT ACA TGG Lys Val Thr Trp ACC GAG ACT Thr Giu Thr 300 AGG AAA CAC Arg Lys His GTT ACT GGC CCA Val Thr Gly Pro GGG GAG CGA TTT Arg Giu Pro Phe CTC AAG Leu Lys 320 GCG ATT GAT GTC Ala Ile Asp Val ATG AAC AAG ATG Met Asn Lys Met GAT GTC GCC ATG Asp Val Ala Met 1007 1055 ACT CTT GGT GTG GTT GCG CTC TTT GGC GAT GGC CCG ACA GCG ATG AGA Thr Leu Ala Val Val Ala Leu Phe Ala Asp Gly Pro Thr Ala Ile Arg I P.%OPERVJMST.EPSPS.N W-1(M18J) 335 GAC Asp CGG Arg TAC Tyr ACG Th r GCC Ala 415 TTC Phe TAA GTG ValI ACG Thr TGC Cys TAC Tyr 400 GAG 01 u Ccc Pro GCT Ala GAG Glu ATC I le 385 GAC Asp GTC ValI GAC Asp TCC Ser CTA Leu 370 ATC Ile GAC Asp CCC Pro TAC Tyr TG *Trp 355 *ACC Thr ACG Th r CAC His GTC Val1 TTC Phe 435 340 AGA Arg AAG Lys CCG Pro AGO Arg ACC Th r 420 GAT Asp GTA Val CTG Leu CCG Pro ATO Met 405 ATC Ile GTG Val1 AAG GAO ACC Lys Glu Thr 360 GGA OCA TCT Gly Ala Ser 375 GAO AAO CTO Glu Lys Leu 390 GCG ATG 0CC Ala Met Ala COG GAC CCT Arg Asp Pro OTO AOC ACT Leu Ser Thr 440 36 345 350 GAG AGO ATO OTT GCG ATC Glu Arg Met Val Ala Ile 365 GTT GAG GAA GGG CCG GAC Val Glu Glu Gly Pro Asp 380 AAC GTG ACG GCO ATC GAC Asn Val Thr Ala Ile Asp 395 TTC TCC CTT 0CC 0CC TOT Phe Ser Leu Ala Ala Cys 410 000 TOC ACC COO AAG ACC Oly Cys Thr Arg Lys Thr 425 430 TTC OTC AAG AAT Phe Val Lys Asn 1103 1151 1199 1247 1295 1337 1340 (2) INFORMATION FOR SEQ ID SEQUENCE CHARACTERISTICS: LENGTH: 444 amino acids TYPE: amino acid TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE Gly Ala Olu Olu Val Lys Leu Pro Ala Ala Leu Ser Olu Asp Val His Val Glu Ala Asp Oly Lys Phe Pro Oly Asn Ala Oly 100 Ala Oly Oly Asn 115 Oiu Arg Pro Ile 130 DESCRIPTION: SEQ ID Ile Val Leu Gin Pro Oly Ser Lys Ser Leu Olu Oly Thr Thr Val Tyr Met Leu Oly Ala 55 Lys Ala Ala Lys Arg Val Olu Asp Ala Lys Ile Ala met Arg Ser 105 Ala Thr Tyr Val Leu 120 Oly Asp Leu Val Val 135 NO: Ile Lys Ser Asn Val Asp Leu Arg Ala Val Glu Olu Leu Thr Asp Oly Gly Leu 140 P 'CPERJm.SEPSPS-q..". 11wuvn 36A Ala Asp Val Asp Cys The Leu Gly Thr Asp Cys Pro Pro Val Arg Val 145 150 155 160 Asn Gly Ile Gly Gly Leu Pro Gly Gly Lys Val Lys Leu Ser Gly Ser 165 170 175 Ile Ser Ser Gin Tyr Leu Ser Ala Leu Leu Met Ala Ala Pro Leu Ala 180 185 190 Leu Gly Asp Val Giu Ile Giu Ile Ile Asp Lys Leu Ile Ser Ile Pro 195 200 205 Tyr Val Giu Met Thr Leu Arg Leu Met Giu Arg Phe Gly Val Lys Ala 210 215 220 Glu His Ser Asp Ser Trp Asp Arg Phe Tyr Ile Lys Gly Gly Gin Lys 225 230 235 240 Tyr Lys Ser Pro Lys Asn Ala Tyr Val Glu Giy Asp Ala Ser Ser Ala 245 250 255 Ser Tyr Phe Leu Ala Giy Ala Ala Ile Thr Gly Gly Thr Val Thr Val 260 265 270 Glu Gly Cys Gly Thr Thr Ser Leu Gin Gly Asp Val Lys Phe Ala Giu 275 280 285 Val Leu Glu Met Met Gly Ala Lys Val Thr Trp Thr Giu Thr Ser Val 290 295 300 Thr Val Thr Gly Pro Pro Arg Giu Pro Phe Gly Arg Lys His Leu Lys 305 310 315 320 Ala Ile Asp Val Asn Met Asn Lys Met Pro Asp Val Ala Met Thr Leu 325 330 335 Ala Val Val Ala Leu Phe Ala Asp Gly Pro Thr Ala Ile Arg Asp Val 340 345 350 Ala Ser Trp Arg Val Lys Giu Thr Glu Arq Met.Val Ala Ile Arg Thr 355 360 365, Giu Leu Thr Lys Leu Gly Ala Ser Val Glu Giu Gly Pro Asp Tyr Cys 370 375 380 Ile Ile Thr Pro Pro Giu Lys Leu Asn Val Thr Ala Ile Asp Thr Tyr 385 390 395 400 Asp Asp His Arg Met Ala Met Ala Phe Ser Leu Ala Ala Cys Ala Giu 405 410 415 Val Pro Val Thr Ile Arg Asp Pro Gly Cys Thr Arg Lys Thr Phe Pro 420 425 430 Asp Tyr Phe Asp Val Leu Ser Thr Phe Val Lys Asn 435 440