METHODS AND COMPOSITIONS FOR CONFERRING AND/OR ENHANCING HERBICIDE TOLERANCE USING PROTOPORPHYRINOGEN IX OXIDASE OF VARIOUS CYANOBACTERIA OR VARIANT THEREOF
20230175004 · 2023-06-08
Inventors
- Soon-Kee Sung (Daejeon, KR)
- Young Ock Ahn (Daejeon, KR)
- Joo Yong WOO (Daejeon, KR)
- Joonseon Yoon (Daejeon, KR)
- Hanul KIM (Daejeon, KR)
- Myoung-Ki Hong (Daejeon, KR)
- Joonghyuk Park (Daejeon, KR)
Cpc classification
C12N15/70
CHEMISTRY; METALLURGY
International classification
Abstract
Provided are protoporphyrinogen IX oxidases derived from various organism or variants thereof, and uses of the same for conferring and/or enhancing herbicide tolerance of a plant and/or an alga.
Claims
1. A polypeptide selected from the group consisting of: (1) a polypeptide comprising an amino acid sequence of modified SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3, wherein one or more amino acid residues selected from the group consisting of N59, S60, R89, F161, V165, A167, Q184, P303, V305, F324, L327, I340, F360, and I40 of the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3 are respectively and independently deleted or substituted with an amino acid selected from the group consisting of M(Met), V(Val), I(Ile), T(Thr), L(Leu), C(Cys), A(Ala), S(Ser), F(Phe), P(Pro), W(Trp), N(Asn), Q(Gln), G(Gly), Y(Tyr), D(Asp), E(Glu), R(Arg), H(His), and K(Lys), which is different from the amino acid at the corresponding position of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3; and (2) a polypeptide comprising an amino acid sequence with at least 95% identity with the amino acid sequence of the polypeptide (1).
2. The polypeptide of claim 1, which is selected from the group consisting of: (1) a polypeptide comprising an amino acid sequence of modified SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3, wherein one or more amino acid residues selected from the group consisting of R89, V165, A167, V305, L327, F360, and I408 of the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3 are respectively and independently deleted or substituted with an amino acid selected from the group consisting of M(Met), V(Val), I(Ile), T(Thr), L(Leu), C(Cys), A(Ala), S(Ser), R(Arg), and W(Trp), which is different from the amino acid at the corresponding position of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3; and (2) a polypeptide comprising an amino acid sequence with at least 95% identity with the amino acid sequence of the polypeptide (1).
3. The polypeptide of claim 1, which is selected from the group consisting of: (a) a polypeptide comprising an amino acid sequence of modified SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3, comprising at least one amino acid mutation selected from the group consisting of: (i) F360M, F360V, F360I, F360T or F360L, (ii) A167C, A167L, or A167I, (iii) V305M or V305L, (iv) R89A, (v) V165S or V165C, (vi) L327T, and (vii) I408R, or I408W, in the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3; or (b) an amino acid sequence having at least 95% sequence identity with the amino acid sequence (a).
4. A polypeptide comprising an amino acid sequence, wherein one selected from the group consisting of the amino acid sequences of SEQ ID NO: 4 to 79 is mutated by substitution of at least one selected from the group consisting of mutated sites 1 to 6 with the amino acid after mutation as defined in the following table: TABLE-US-00021 SEQ Amino acid after mutation Mutated Site ID (substitution) at the 1 2 3 4 5 6 NO mutated site A C or S C, I, or L M or L T M, I, L, T, or V 1 Thermosynechococcus R89 V165 A167 V305 L327 F360 elongatus PKUAC- SCTE542 2 Cyanobacteria bacterium R89 V165 A167 V305 L327 F360 J003 3 Thermosynechococcus R89 V165 A167 V305 L327 F360 vulcanus NIES-2134 4 Synechococcus lividus R92 V168 A170 V312 L334 F367 5 Microcoleaceae bacterium R93 V174 A176 V319 L341 Y374 UBA10368 6 Microcoleaceae bacterium R87 V168 A170 V313 L335 Y368 UBA11344 7 Oscillatoriales R92 V173 A175 V327 L349 Y382 cyanobacterium (TAE85894.1) 8 Cyanobacteria bacterium R92 V166 A168 V309 L331 F364 UBA8156 9 Rubidibacter lacunae R86 V160 A162 V309 L331 F364 10 Hydrocoleum sp. CS-953 R92 V171 A173 V317 L339 F372 11 Oscillatoriales R92 V173 A175 V327 L349 Y382 cyanobacterium (TAE55813.1) 12 Crinalium epipsammum R85 V166 A168 V312 L334 F367 13 Oscillatoriales R92 V173 A175 V327 L349 Y382 cyanobacterium (TAE70643.1) 14 Oscillatoriales R92 V173 A175 V327 L349 Y382 cyanobacterium (TAE14532.1) 15 Cyanobacteria bacterium R85 V166 A168 V312 L334 F367 QS_8_64_29 16 Lyngbya aestuarii R93 V174 A176 V320 L342 Y375 17 Tychonema bourrellyi R93 V174 A176 V319 L341 F374 18 Oscillatoriales R93 V174 A176 V319 L341 Y374 cyanobacterium (TAG91209.1) 19 Cyanobacteria bacterium R85 V160 A162 V308 L330 F363 SW_9_44_58 20 Trichodesmium R92 V173 A175 V319 L341 Y374 erythraeum 21 Geitlerinema sp. PCC R105 V180 A182 V332 L355 F388 9228 22 Oscillatoriales R104 V185 A187 V334 L356 F389 cyanobacterium (TAD79992.1) 23 Oscillatoriales R93 V174 A176 V319 L341 Y374 cyanobacterium (TAD82603.1) 24 Oscillatoriales R93 V174 A176 V319 L341 Y374 cyanobacterium (TAD95528.1) 25 Limnothrix sp. PR1529 R88 V169 A171 V318 L340 F373 26 Planktothricoides sp. R102 V183 A185 V329 L352 F385 SR001 27 Limnothrix sp. CACIAM R88 V169 A171 V318 L340 F373 69d 28 Okeania hirsuta R92 V172 A174 V318 L340 F373 (WP_124155207.1) 29 Okeania hirsuta R92 V172 A174 V318 L340 F373 (WP_124145785.1) 30 Desertifilum sp. IPPAS B- R96 V177 A179 V324 L346 Y379 1220 31 Synechococcus sp. R105 V179 A181 V322 L344 F377 65AY6Li 32 Synechococcus sp. R105 V179 A181 V322 L344 F377 65AY6A5 33 Synechococcus sp. R105 V179 A181 V322 L344 F377 60AY4M2 34 Synechococcus sp. R105 V179 A181 V322 L344 F377 63AY4M1 35 Synechococcus sp. R105 V179 A181 V322 L344 F377 63AY4M2 36 Cyanobacteria bacterium R100 V177 A179 V323 L345 F378 J007 37 Spirulina major R85 V166 A168 V311 L333 F366 38 Euhalothece sp. KZN 001 R85 V160 A162 V306 L328 F361 39 Dactylococcopsis salina R85 V160 A162 V306 L328 F361 40 Synechococcus sp. PCC R89 V163 A165 V306 L328 Y361 7336 41 Arthrospira sp. O9.13F R93 V174 A176 V320 L342 Y375 42 Arthrospira platensis R93 V174 A176 V320 L342 Y375 (WP_006622155.1) 43 Arthrospira platensis R93 V174 A176 V321 L343 Y376 (WP_006617829.1) 44 Pseudanabaena sp. R98 V172 A174 V318 L340 F373 BC1403 45 Pseudanabaena sp. R97 V171 A173 V316 L338 F371 ‘Roaring Creek’ 46 Pseudanabaena sp. R98 V172 A174 V319 L341 F374 (HBC40803.1) 47 Synechococcus sp. JA-2- R106 V180 A182 V343 L365 F398 3B′a(2-13) 48 Pseudanabaena biceps R97 V171 A173 V317 L339 F372 49 Pseudanabaena sp. R98 V172 A174 V318 L340 F373 (PZV12410.1) 50 Pseudanabaena sp. PCC R104 V178 A180 V336 L358 F391 7367 51 Pseudanabaena sp. SR411 R98 V172 A174 V319 L341 F374 52 Pseudanabaena frigida R98 V172 A174 V318 L340 F373 53 Pseudanabaena sp. R99 V173 A175 V320 L342 F375 (PZU98053) 54 Oscillatoriales R106 V180 A182 V327 L349 F382 cyanobacterium CG2_30_44_21 55 Chlamydomonas R167 V241 A243 V389 L418 Y451 reinhardtii 56 Volvox carteri f. R168 V242 A244 V389 L418 Y451 nagariensis 57 Chondrus crispus R106 V181 A183 V328 L350 Y383 (CHC_T00000813001) 58 Galdieria sulphuraria R167 V242 A244 V399 L421 Y454 59 Pseudanabaena sp. R98 V172 A174 V319 L341 F374 ABRG5-3 60 Arthrospira platensis YZ R93 V174 A176 V321 L343 Y376 61 Gloeobacter kilaueensis R94 V167 A169 V301 L323 F356 JS1 62 Gloeobacter violaceus R91 M164 A166 V298 L320 F353 PCC 7421 63 Panicum hallii var. hallii R145 V219 A221 V366 L394 Y427 64 Porphyra umbilicalis R157 V232 A234 V381 L403 Y436 65 Ostreococcus tauri R124 V198 A200 V349 L380 Y415 66 Ectocarpus siliculosus R144 V220 A222 V374 L396 Y429 67 Nannochloropsis gaditana R87 V162 A164 V311 L333 Y365 CCMP526 68 Ostreococcus lucimarinus R67 V141 A143 V288 L319 Y354 CCE9901 69 Guillardia theta R159 V233 A235 V381 L414 Y447 CCMP2712 70 Cyanidioschyzon merolae R168 V259 A261 V413 L435 Y468 strain 10D 71 Bathycoccus prasinos R152 V227 A229 V378 L409 Y444 72 Myxococcus Xanthus R94 I168 A170 I311 L332 M365 Synthetic construct 73 Myxococcus virescens R94 I168 A170 I310 L331 M364 74 Myxococcus macrosporus R86 I159 A161 I304 L325 M358 DSM 14697 75 Myxococcus hansupus R94 I168 A170 I310 L331 M364 76 Myxococcus fulvus R85 I159 A161 I305 L326 M359 77 Myxococcus fulvus R85 I159 A161 I305 L326 M359 78 Myxococcus stipitatus R85 I159 A161 I303 L324 M357 79 Hyalangium minutum A86 I160 A162 I305 L326 M359
5. A polynucleotide encoding the polypeptide of claim 1.
6. A recombinant vector comprising the polynucleotide of claim 5.
7. A recombinant cell comprising the recombinant vector of claim 6.
8. A composition for conferring or enhancing herbicide tolerance of a plant or algae, comprising one or more selected from the group consisting of: (1) one or more selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1; (2) a polynucleotide encoding the polypeptide of (1); (3) a recombinant vector comprising the polynucleotide of (2); and (4) a recombinant cell comprising the recombinant vector of (3).
9. The composition of claim 8, wherein the herbicide is an herbicide inhibiting protoporphyrinogen IX oxidase.
10. The composition of claim 8, wherein the herbicide is at least one selected from the group consisting of pyrimidinediones, diphenyl-ethers, phenylpyrazoles, N-phenylphthalimides, phenylesters, thiadiazoles, oxadiazoles, triazolinones, oxazolidinediones, pyraclonil, flufenpyr-ethyl, and profluazol.
11. The composition of claim 10, wherein the herbicide is at least one selected from the group consisting of butafenacil, saflufenacil, benzfendizone, tiafenacil, fomesafen, oxyfluorfen, aclonifen, acifluorfen, bifenox, ethoxyfen, lactofen, chlomethoxyfen, chlorintrofen, fluoroglycofen-ethyl, halosafen, pyraflufen-ethyl, fluazolate, flumioxazin, cinidon-ethyl, flumiclorac-pentyl, fluthiacet, thidiazimin, oxadiargyl, oxadiazon, carfentrazone, sulfentrazone, azafenidin, pentoxazone, pyraclonil, flufenpyr-ethyl, profluazol, phenopylate, carbamate analogues of phenopylate, and agriculturally acceptable salt thereof.
12. The composition of claim 8, wherein the plant or algae further comprise a second herbicide-tolerant polypeptide or a gene encoding the same, and its tolerance to the second herbicide is conferred or enhanced.
13. The composition of claim 12, wherein the second herbicide is selected from the group consisting of glyphosate, glufosinate, dicamba, 2,4-D (2,4-Dichlorophenoxyacetic acid), isoxaflutole, ALS (acetolactate synthase)-inhibiting herbicide, photosystem II-inhibiting herbicide, phenylurea-based herbicide, bromoxynil-based herbicide, and combinations thereof.
14. The composition of claim 12, wherein the second herbicide-tolerant polypeptide is one or more selected from the group consisting of: glyphosate herbicide-tolerant EPSPS (glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase), GOX (glyphosate oxidase), GAT (glyphosate-N-acetyltransferase) or glyphosate decarboxylase; glufosinate herbicide-tolerant PAT (phosphinothricin-N-acetyltransferase); dicamba herbicide-tolerant DMO (dicamba monooxygenase); 2,4-D (2,4-dichlorophenoxyacetic acid) herbicide-tolerant 2,4-D monooxygenase or AAD (aryloxyalkanoate dioxygenase); ALS (acetolactate synthase)-inhibiting sulfonylurea-based herbicide-tolerant ALS (acetolactate synthase), AHAS (acetohydroxyacid synthase) or AtAHASL (Arabidopsis thaliana acetohydroxyacid synthase large subunit); photosystem II-inhibiting herbicide-tolerant photosystem II protein D1; phenylurea herbicide-tolerant Cytochrome P450; plastid-inhibiting herbicide-tolerant HPPD (hydroxyphenylpyruvate dioxygenase); bromoxynil herbicide-tolerant nitrilase; and combinations thereof.
15. The composition of claim 12, wherein the gene encoding the second herbicide-tolerant polypeptide is one or more selected from the group consisting of: glyphosate herbicide-tolerant cp4 epsps, mepsps, 2mepsps, goxv247, gat4601 or gat4621 gene; glufosinate herbicide-tolerant BAR or PAT gene; dicamba herbicide-tolerant dmo gene; 2,4-D(2,4-dichlorophenoxyacetic acid) herbicide-tolerant AAD-1 or AAD-12 gene; isoxaflutole herbicide-tolerant HPPDPF W336 gene; sulfonylurea herbicide-tolerant ALS, Csr1, Csr1-1, Csr1-2, GM-HRA, S4-HRA, Zm-HRA, SurA or SurB gene; photosystem II-inhibiting herbicide-tolerant psbA gene; phenylurea herbicide-tolerant CYP76B1 gene; bromoxynil herbicide-tolerant bxn gene; and combinations thereof.
16. A transformant of a plant or algae having herbicide tolerance, or a clone or progeny thereof, comprising (1) at least one selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1, or (2) a polynucleotide encoding the polypeptide of (1).
17. The transformant, clone, or progeny thereof of claim 16, wherein the transformant is an alga, or a cell, protoplast, callus, hypocotyl, seed, cotyledon, shoot, or whole body of a plant.
18. A method of preparing a transgenic plant or algae having herbicide tolerance, the method comprising introducing (1) at least one selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1, or (2) a polynucleotide encoding the polypeptide of (1), into an alga, or a cell, protoplast, callus, hypocotyl, seed, cotyledon, shoot, or whole body of a plant.
19. A method of conferring or enhancing herbicide tolerance of a plant or algae, the method comprising introducing (1) at least one selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1, or (2) a polynucleotide encoding the polypeptide of (1), into an alga, or a cell, protoplast, callus, hypocotyl, seed, cotyledon, shoot, or whole body of a plant.
20. A method of controlling weeds in a cropland, the method comprising: providing the cropland with a plant comprising (1) at least one selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1, or (2) a polynucleotide encoding the polypeptide of (1), and applying an effective dosage of protoporphyrinogen IX oxidase-inhibiting herbicide to the cropland or the plant.
21. The method of claim 20, wherein the step of applying an effective dosage of protoporphyrinogen IX oxidase-inhibiting herbicide to the cropland is performed by applying an effective dosage of two or more kinds of protoporphyrinogen IX oxidase-inhibiting herbicides sequentially or simultaneously.
22. The method of claim 20, wherein the plant further comprises a second herbicide-tolerant polypeptide or a gene encoding the same, and the step of applying an effective dosage of protoporphyrinogen IX oxidase-inhibiting herbicide to the cropland is performed by applying effective dosages of the protoporphyrinogen IX oxidase-inhibiting herbicide and a second herbicide are applied sequentially or simultaneously.
23. A method of removing an undesired aquatic organism from a culture media, the method comprising: providing a culture media with algae comprising (1) at least one selected from the group consisting of a polypeptide of SEQ ID NO: 1, a polypeptide of SEQ ID NO: 2, a polypeptide of SEQ ID NO: 3, and the polypeptide of claim 1, or (2) a polynucleotide encoding the polypeptide of (1), and applying an effective dosage of protoporphyrinogen IX oxidase-inhibiting herbicide to the culture media.
Description
DESCRIPTION OF DRAWINGS
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MODE FOR INVENTION
[0178] Hereinafter, the present invention will be described in detail with reference to Examples. However, these Examples are for illustrative purposes only, and the invention is not intended to be limited by these Examples.
Example 1. Isolation of PPO Genes from Prokaryotic Species
[0179] PPO sequence information was obtained from Genebank database of species including Thermosynechococcus elongatus PKUAC-SCTE542, Cyanobacteria bacterium J003, and Thermosynechococcus vulcanus NIES-2134. PPO genes were synthesized (Integrated DNA Technologies). PPO genes were amplified under the condition of Table 2 using primers listed in Table 1 to clone them into pMAL-c2X vector (
[0180] PCR mixture:
[0181] Template (synthetic DNA of each of CyPPO19, CyPPO20, and CyPPO18) 1 μl
[0182] 10× buffer 5 μl
[0183] dNTP mixture (10 mM each) 1 μl
[0184] Forward primer (10 μM, refer to Table 1) 1 μl
[0185] Reverse primer (10 μM, refer to Table 1) 1 μl
[0186] DDW 40 μl
[0187] Pfu-X (Solgent, 2.5 units/μl) 1 μl
[0188] Total 50 μl
[0189] Each PPO gene was designated as CyPPO19 isolated from Thermosynechococcus elongatus PKUAC-SCTE542, CyPPO20 from Cyanobacteria bacterium J003, and CyPPO18 from Thermosynechococcus vulcanus NIES-2134.
TABLE-US-00002 TABLE 1 SEQ ID Strain Primer Sequence NO Thermosynechococcus Cy19 GAAGATCTATGAGTGAGGTAGATGTCG 159 elongatus PKUAC- BglII_F SCTE542 Cy19 SalI_R ACGCGTCGACCTAGGGCTGGCCTCCTGA 160 Cyanobacteria Cy20 GAAGATCTATGATGGAGGTAGATGTCGC 161 bacterium J003 BglII_F Cy20 SalI_R ACGCGTCGACTTAACCTCCTGAAAGGTA 162 GGC Thermosynechococcus Cy18 CCAGATCTATGATTGAGGTAGATGTC 163 vulcanus NIES-2134 BglII_F G Cy18 SalI_R CCGTCGACCTAGGACTGGCCTCCTGC 164
TABLE-US-00003 TABLE 2 PCR Condition 94° C. 4 min. 1 cycle 94° C. 30 sec. 25 cycles 56° C. 30 sec. 72° C. 1.5 min. 72° C. 5 min. 1 cycle 4° C. 5 min. 1 cycle
Example 2. Construction of PPO Variants
[0190] In order to enhance PPO-inhibiting herbicide tolerance of CyPPO19, CyPPO20, and CyPPO18, a mutation(s) at the position interacting with herbicide was introduced, to prepare variants of CyPPO19, CyPPO20, and CyPPO18.
[0191] Detailed experimental procedure was as follows:
[0192] Using primers listed in Table 3, PCR was carried out to amplify PPO genes under the conditions shown in Table 4.
[0193] PCR reaction mixture:
[0194] Template (synthetic DNA of each of CyPPO19, CyPPO20, or CyPPO18) 1 μl
[0195] 10× buffer 5 μl
[0196] dNTP mixture (10 mM each) 1 μl
[0197] Forward primer (10 μM) 1 μl
[0198] Reverse primer (10 μM) 1 μl
[0199] DDW 40 μl
[0200] Pfu-X (Solgent, 2.5 units/pi) 1 μl
[0201] Total 50 μl
TABLE-US-00004 TABLE 3 Primers sequence information for cloning of genes to pET303-CT His vector SEQ ID Strain Primer Sequence NO Thermosynechococcus Cy19 AGTATCTAGAATGAGTGAGGTAGATG 165 elongatus PKUAC- XbaI_F TCG SCTE542 Cy19 TTAACTCGAGGGGCTGGCCTCCTGAA 166 XhoI_R AG Cyanobacteria Cy20 GCTCTAGAATGATGGAGGTAGATGTCGC 167 bacterium J003 XbaI_F Cy20 CCGCTCGAGACCTCCTGAAAGGTAGGC 168 XhoI_R Thermosynechococcus Cy18 CCTCTAGAATGATTGAGGTAGATGTC 169 vulcanus NIES-2134 XbaI_F G Cy18 CCCTCGAGGGACTGGCCTCCTGCAA 170 XhoI_R GA
[0202] Amplified PCR products above and pET303-CT His vector (Invitrogen;
[0203] Variants of CyPPO19, CyPPO20, and CyPPO18 were constructed using CyPPO19, CyPPO20, and CyPPO18 genes cloned in pET303-CT His vector with primers listed in Tables 5 to 7 under the condition as following.
[0204] PCR reaction mixture
[0205] Template 1 μl
[0206] 10× buffer 5 μl
[0207] dNTP mixture (10 mM each) 1 μl
[0208] forward primer (10 μM) 1 μl
[0209] reverse primer (10 μM) 1 μl
[0210] DDW 40 μl
[0211] Pfu-X (Solgent, 2.5 unit/μl) 1 μl
[0212] Total 50 μl
TABLE-US-00005 TABLE 4 PCR condition 94° C. 4 min. 1 cycle 94° C. 30 sec. 17-25 cycles 56~60° C. 30 sec. 72° C. 3 min. 72° C. 5 min. 1 cycle 4° C. 5 min. 1 cycle
TABLE-US-00006 TABLE 5 Primer list for CyPPO19 variant construction CyPPO19 mutagenesis SEQ ID primer sequence (5′.fwdarw.3′) NO Cy19 R89A F GATCGCCACCTGCCGGCGTACATCTACTGGCGG 171 Cy19 R89A R CCGCCAGTAGATGTACGCCGGCAGGTGGCGATC 172 Cy19 V165C F GTCTCTGGGTGCTATGCGGGTGATCCACAACAA 173 Cy19 V165C R ACCCGCATAGCACCCAGAGACAAAGGGCGCCAC 174 Cy19 V165S F CCCTTTGTCTCTGGGAGTTATGCGGGTGATCCA 175 Cy19 V165S R TGGATCACCCGCATAACTCCCAGAGACAAAGGG 176 Cy19 A167C F GCGCCCTTTGTCTCTGGGGTTTATTGCGGT 177 Cy19 A167C R AGCACTCAGTTGTTGTGGATCACCGCAATA 178 Cy19 A167L F GTCTCTGGGGTTTATCTGGGTGATCCACAACAA 179 Cy19 A167L R TTGTTGTGGATCACCCAGATAAACCCCAGAGAC 180 Cy19 A167I F GTCTCTGGGGTTTATATCGGTGATCCACAACAA 181 Cy19 A167I R TTGTTGTGGATCACCGATATAAACCCCAGAGAC 182 Cy19 V305L F CATTCCCTATCCCACCCTAGCCTGTGTGGTCTTG 183 Cy19 V305L R CAAGACCACACAGGCTAGGGTGGGATAGGGAAT 184 G Cy19 V305M F TATCCCACCATGGCCTGTGTGGTCTTGGCCTAT 185 Cy19 V305M R CACACAGGCCATGGTGGGATAGGGAATGGTGGCC 186 AA Cy19 L327T F AGTGTCCGCCCCGGCTTTGGCGTAACCATT 187 Cy19 L327T R GCGGATGCCCTGACTGCGAGGAATGGTTAC 188 Cy19 F360I F CAAGTCTTTACGAGTATTATTGGCGGTGCTAC 189 Cy19 F360I R GTAGCACCGCCAATAATACTCGTAAAGACTTG 190 Cy19 F360L F GTCTTTACGAGTTTAATTGGCGGTGCTACG 191 Cy19 F360L R CGTAGCACCGCCAATTAAACTCGTAAAGAC 192 Cy19 F360M F GGCAAGTCTTTACGAGTATGATTGGCGGTGCTAC 193 GG Cy19 F360M R CCGTAGCACCGCCAATCATACTCGTAAAGACTTG 194 CC Cy19 F360V F CAAGTCTTTACGAGTGTTATTGGCGGTGCTAC 195 Cy19 F360V R GTAGCACCGCCAATAACACTCGTAAAGACTTG 196 Cy19 F360T F TTTACGAGTACTATTGGCGGTGCTACGGATCCTGA 197 Cy19 F360T R CCGCCAATAGTACTCGTAAAGACTTGCCAACCGG 198 Cy19 I408R F GTTTGGCGACGGGCGAGACCCCAATATATGGTG 199 Cy19 I408R R CACCATATATTGGGGTCTCGCCCGTCGCCAAAC 200 Cy19 I408W F AGGTTTGGCGACGGGCGTGGCCCCAATATATG 201 Cy19 I408W R CATATATTGGGGCCACGCCCGTCGCCAAACCT 202 Cy19 V165C + A167C CCTTTGTCTCTGGGTGTTATTGCGGTGATCCACAA 203 F CAACTG Cy19 V165C + A167C CAGTTGTTGTGGATCACCGCAATAACACCCAGAG 204 R ACAAAGG Cy19 V165C + A167L GGCGCCCTTTGTCTCTGGGTGCTACCTGGGTGAT 205 F CCACAACA Cy19 V165C + A167L TGTTGTGGATCACCCAGGTAGCACCCAGAGACAA 206 R AGGGCGCC Cy19 V165S + A167C GGCGCCCTTTGTCTCTGGGAGCTACTGCGGTGAT 207 F CCACAACAAC Cy19 V165S + A167C GTTGTTGTGGATCACCGCAGTAGCTCCCAGAGAC 208 R AAAGGGCGCC Cy19 V165C + A167I GGCGCCCTTTGTCTCTGGGTGCTACATCGGTGATC 209 F CACA Cy19 V165C + A167I TGTGGATCACCGATGTAGCACCCAGAGACAAAG 210 R GGCGCC Cy19 V165S + A167I GGCGCCCTTTGTCTCTGGGAGCTACATCGGTGAT 211 F CCACA Cy19 V165S + A167I TGTGGATCACCGATGTAGCTCCCAGAGACAAAGG 212 R GCGCC Cy19 V165S + A167L CCTTTGTCTCTGGGTCTTATCTGGGTGATCCACAA 213 F CAACTG Cy19 V165S + A167L CAGTTGTTGTGGATCACCCAGATAAGACCCAGAG 214 R ACAAAGG
TABLE-US-00007 TABLE 6 Primer list for CyPPO20 variant construction SEQ CyPPO20 ID mutagenesis primer sequence (5′.fwdarw.3′) NO Cy20 R89A F GATCGCCACCTACCGGCGTACATCTACTGGCGG 215 Cy20 R89A R CCGCCAGTAGATGTACGCCGGTAGGTGGCGATC 216 Cy20 V165C F CCCTTTGTCTCTGGGTGTTACGCCGGTGATCCG 217 Cy20 V165C R CGGATCACCGGCGTAACACCCAGAGACAAAGGG 218 Cy20 V165S F CCCTTTGTCTCTGGGAGTTACGCCGGTGATCCG 219 Cy20 V165S R CGGATCACCGGCGTAACTCCCAGAGACAAAGGG 220 Cy20 A167C F GTCTCTGGGGTTTACTGTGGTGATCCGCAACAA 221 Cy20 A167C R TTGTTGCGGATCACCACAGTAAACCCCAGAGAC 222 Cy20 A167L F GTCTCTGGGGTTTACCTCGGTGATCCGCAACAA 223 Cy20 A167L R TTGTTGCGGATCACCGAGGTAAACCCCAGAGAC 224 Cy20 A1671 F GTCTCTGGGGTTTACATTGGTGATCCGCAACAA 225 Cy20 A1671 R TTGTTGCGGATCACCAATGTAAACCCCAGAGAC 226 Cy20 V305L F CATCCCCTATCCCACCCTAGCCTGTGTGGTCTTG 227 Cy20 V305L R CAAGACCACACAGGCTAGGGTGGGATAGGGGATG 228 Cy20 V305M F ATCCCCTATCCCACCATGGCCTGTGTGGTCTTG 229 Cy20 V305M R CAAGACCACACAGGCCATGGTGGGATAGGGGAT 230 Cy20 L327T F CCCGGATTTGGCGTAACGATTCCTCGTGGCCAG 231 Cy20 L327T R CTGGCCACGAGGAATCGTTACGCCAAATCCGGG 232 Cy20 I340T F CGTACCCTTGGCACCACATGGTCGTCCTGTCTT 233 Cy20 I340T R AAGACAGGACGACCATGTGGTGCCAAGGGTACG 234 Cy20 F360I F CAAGTCTTTACAAGTACCATTGGCGGTGCCACG 235 Cy20 F360I R CGTGGCACCGCCAATGGTACTTGTAAAGACTTG 236 Cy20 F360L F CAAGTCTTTACAAGTCTGATTGGCGGTGCCACG 237 Cy20 F360L R CGTGGCACCGCCAATCAGACTTGTAAAGACTTG 238 Cy20 F360M F CAAGTCTTTACAAGTATGATTGGCGGTGCCACG 239 Cy20 F360M R CGTGGCACCGCCAATCATACTTGTAAAGACTTG 240 Cy20 F360V F CAAGTCTTTACAAGTGTTATTGGCGGTGCCACG 241 Cy20 F360V R CGTGGCACCGCCAATAACACTTGTAAAGACTTG 242 Cy20 I408R F GTTTGGCGACGGGCGAGGCCCCAATATCTTGTG 243 Cy20 I408R R CACAAGATATTGGGGCCTCGCCCGTCGCCAAAC 244 Cy20 I408W F GTTTGGCGACGGGCGTGGCCCCAATATCTTGTG 245 Cy20 I408W R CACAAGATATTGGGGCCACGCCCGTCGCCAAAC 246 Cy20 V165C + A167C CCCTTTGTCTCTGGGTGTTACTGTGGTGATCCGCAACAA 247 F Cy20 V165C + A167C TTGTTGCGGATCACCACAGTAACACCCAGAGACAAAGGG 248 R Cy20 V165C + A167I CCCTTTGTCTCTGGGTGTTACATTGGTGATCCGCAACAA 249 F Cy20 V165C + A167I TTGTTGCGGATCACCAATGTAACACCCAGAGACAAAGGG 250 R Cy20 V165C + A167L CCCTTTGTCTCTGGGTGTTACCTCGGTGATCCGCAACAA 251 F Cy20 V165C + A167L TTGTTGCGGATCACCGAGGTAACACCCAGAGACAAAGGG 252 R Cy20 V165S + A167C CCCTTTGTCTCTGGGAGTTACTGTGGTGATCCGCAACAA 253 F Cy20 V165S + A167C TTGTTGCGGATCACCACAGTAACTCCCAGAGACAAAGGG 254 R Cy20 V165S + A167I CCCTTTGTCTCTGGGAGTTACATTGGTGATCCGCAACAA 255 F Cy20 V165S + A167I TTGTTGCGGATCACCAATGTAACTCCCAGAGACAAAGGG 256 R Cy20 V165S + A167L CCCTTTGTCTCTGGGAGTTACCTCGGTGATCCGCAACAA 257 F Cy20 V165S + A167L TTGTTGCGGATCACCGAGGTAACTCCCAGAGACAAAGGG 258 R
TABLE-US-00008 TABLE 7 Primer list for CyPPO18 variant construction CyPPO18 mutagenesis SEQ primer sequence (5′.fwdarw.3′) ID NO Cy18 R89A F GATCGCCACCTACCGGCATACATCTACTGGCG 259 Cy18 R89A R CGCCAGTAGATGTATGCCGGTAGGTGGCGATC 260 Cy18 V165C F CCCTTTGTCTCTGGGTGTTATGCCGGTGATC 261 Cy18 V165C R GATCACCGGCATAACACCCAGAGACAAAGGG 262 Cy18 V165S F CCCTTTGTCTCTGGGAGTTATGCCGGTGATC 263 Cy18 V165S R GATCACCGGCATAACTCCCAGAGACAAAGGG 264 Cy18 A167C F GTCTCTGGGGTTTATTGCGGTGATCCGCAAC 265 Cy18 A167C R GTTGCGGATCACCGCAATAAACCCCAGAGAC 266 Cy18 A167L F GTCTCTGGGGTTTATCTCGGTGATCCGCAAC 267 Cy18 A167L R GTTGCGGATCACCGAGATAAACCCCAGAGAC 268 Cy18 A167I F GTCTCTGGGGTTTATATCGGTGATCCGCAAC 269 Cy18 A167I R GTTGCGGATCACCGATATAAACCCCAGAGAC 270 Cy18 V305L F CATCCCCTATCCCACCCTAGCCTGTGTGGTGTTG 271 Cy18 V305L R CAACACCACACAGGCTAGGGTGGGATAGGGGATG 272 Cy18 V305M F CATCCCCTATCCCACCATGGCCTGTGTGGTGTTG 273 Cy18 V305M R CAACACCACACAGGCCATGGTGGGATAGGGGATG 274 Cy18 L327T F CCGGATTTGGAGTAACGGTTCCTCGTGGTC 275 Cy18 L327T R GACCACGAGGAACCGTTACTCCAAATCCGG 276 Cy18 F360I F CAAGTCTTCACCAGTATTATTGGCGGTGCTAC 277 Cy18 F360I R GTAGCACCGCCAATAATACTGGTGAAGACTTG 278 Cy18 F360L F GTCTTCACCAGTTTGATTGGCGGTGCTAC 279 Cy18 F360L R GTAGCACCGCCAATCAAACTGGTGAAGAC 280 Cy18 F360M F GCAAGTCTTCACCAGTATGATTGGCGGTGCTACGG 281 Cy18 F360M R CCGTAGCACCGCCAATCATACTGGTGAAGACTTGC 282 Cy18 F360V F CAAGTCTTCACCAGTGTTATTGGCGGTGCTAC 283 Cy18 F360V R GTAGCACCGCCAATAACACTGGTGAAGACTTG 284 Cy18 V165C + A167L GCCCCCTTTGTCTCTGGGTGCTACCTCGGTGATCCG 285 F CAACAA Cy18 V165C + A167L TTGTTGCGGATCACCGAGGTAGCACCCAGAGACAA 286 R AGGGGGC Cy18 V165S + A167C GCCCCCTTTGTCTCTGGGAGCTACTGCGGTGATCCG 287 F CAACAA Cy18 V165S + A167C TTGTTGCGGATCACCGCAGTAGCTCCCAGAGACAA 288 R AGGGGGC Cy18 V165C + A167C CCCCCTTTGTCTCTGGGTGCTATTGCGGTGATCCGC 289 F A Cy18 V165C + A167C TGCGGATCACCGCAATAGCACCCAGAGACAAAGGG 290 R GG Cy18 V165C + A167I CCCCCTTTGTCTCTGGGTGCTACATCGGTGATCCGC 291 F A Cy18 V165C + A167I TGCGGATCACCGATGTAGCACCCAGAGACAAAGGG 292 R GG Cy18 V165S + A167I CCCCCTTTGTCTCTGGGAGCTACATCGGTGATCCGC 293 F A Cy18 V165S + A167I TGCGGATCACCGATGTAGCTCCCAGAGACAAAGGG 294 R GG Cy18 V165S + A167L GCCCCCTTTGTCTCTGGGAGCTACCTCGGTGATCCG 295 F CAACAA Cy18 V165S + A167L TTGTTGCGGATCACCGAGGTAGCTCCCAGAGACAA 296 R AGGGGGC
Example 3. Verification of PPO-Inhibiting Herbicide Tolerance of PPO Variants (Test in E. coli)
[0213] To enhance the PPO-inhibiting herbicide resistance of CyPPO19 and CyPPO18, PPO variant genes of the above example 2 were constructed. They were transformed to BT3 (ΔPPO) strain which is deficient of PPO activity and cultured in LB media with PPO-inhibiting herbicide, thereby examining whether growth of transformed BT3 was not inhibited.
[0214] Detailed experimental procedure was as follows:
[0215] BT3 competent cells were transformed with the pET303-CyPPO19 (wild type), pET303-CyPPO18 (wild type) plasmids, and those with a mutation(s) constructed (refer to example 2) via heat shock method, and were cultured in LB agar media containing ampicillin.
[0216] Single colony transformed with each CyPPO gene was cultured in 3 mL of LB broth (LPSS) containing ampicillin for more than 12 hours, and then was subcultured in LB broth until absorbance (OD.sub.600) reached 0.5 to 1. Then, it was diluted with LB broth to OD.sub.600=0.5. Again, the diluted solution was serially diluted 4 times by a factor of one tenth.
[0217] The LB agar media (LB 25 g/L, Bacto agar 12 g/L) containing ampicillin (100 μg/mL) and 0 to 2,000 μM of various herbicides were prepared. Herbicide solution stocks were all prepared in DMSO.
[0218] Then, 10 μL of each diluted solution of E. coli was dropped on the plate and cultured at 37° C. under dark for 16-20 hours. PPO-inhibiting herbicide resistance was evaluated with the extent of E. coli growth containing each gene was observed.
[0219] Herbicides used for tests were listed in Table 8.
TABLE-US-00009 TABLE 8 Family Herbicide Pyrimidinedione herbicide Tiafenacil Saflufenacil Diphenyl ether herbicide Fomesafen Oxyfluorfen N-phenylphthalimides herbicide Flumioxazin Triazolinones herbicide Sulfentrazone Carfentrazone
[0220] The extent of herbicide resistance was evaluated by the relative growth of variants to that of wild type, and listed in Tables 9 and 10 and
TABLE-US-00010 TABLE 9 No. Variant Tiafenacil Saflufenacil Flumioxazin Fomesafen Sulfentrazone Oxyfluorfen Carfentrazone 1 R89A + ++ ++++ +++ ++ ++ + + F360M 2 R89A + ++++ ++++ ++++ + +++ + + F360V 3 R89A + +++ ++++ +++ + +++ + + F360I 4 R89A + ++ +++ ++ + ++ + + F360L 5 R89A + +++ +++ +++ ++ +++ + + F360T 6 V165C + ++++ ++++ ++++ + ++++ + + F360I 7 V165C + ++++ ++++ ++++ +++ ++++ ++ + F360M 8 V165C + ++++ ++++ ++++ + ++++ ++ + F360V 9 V165C + ++++ ++++ ++++ +++ ++++ ++ + F360L 10 V165S + ++++ ++++ ++++ + ++++ ++ + F360V 11 V165S + ++++ ++++ ++++ ++ +++ ++ + F360L 12 V165S + ++++ +++ +++ + ++ + + F360T 13 A167C + ++++ +++ ++++ + ++ + + F360I 14 A167L + ++++ ++++ ++++ ++ ++ + + F360M 15 A167I + +++ +++ +++ + + + + F360L 16 A167L + +++ +++ +++ + ++ + + F360T 17 A167C + ++++ ++++ ++++ + + ++ + F360M 18 A167C + +++ +++ +++ + + + + F360L 19 A167C + ++++ +++ +++ + + + + F360V 20 V305M + ++++ ++++ ++++ + ++ + + F360I 21 V305L + +++ ++++ ++++ +++ + ++ + F360M 22 V305M + ++++ ++++ ++++ +++ ++ ++ + F360M 23 V305M + ++++ ++++ ++++ + + ++ + F360V 24 V305M + ++++ ++++ ++++ ++ ++ ++ + F360L 25 V305L + ++++ ++++ ++++ +++ ++ ++ + F360L 26 V305M + ++ ++ ++ ++ + + + F360T 27 L327T + ++++ ++ ++++ + +++ ++ + F360I 28 L327T + +++ + +++ + + ++ + F360M 29 L327T + ++++ ++ ++++ + ++ ++ + F360V 30 L327T + ++++ + ++++ ++ ++ ++ + F360L 31 L327T + ++ + + + + + + F360T 32 I408W + ++++ +++ +++ +++ +++ ++ + F360I 33 I408R + +++ ++ ++ + + + + F360M 34 I408W + ++++ +++ ++++ +++ +++ ++ + F360V 35 I408R + ++ + + + + + + F360L 36 I408W + ++ ++ + + + + + F360T 37 R89A + ++++ ++++ ++++ ++ +++ ++ + V165C + F360I 38 R89A + ++++ ++++ ++++ +++ +++ +++ + V165S + F360M 39 R89A + ++++ ++++ ++++ + +++ + + V165C + F360V 40 R89A + +++++ +++++ +++++ +++ +++++ +++ + A167I + F360V 41 R89A + ++++ ++++ ++++ ++ ++++ +++ ++ A167C + F360L 42 R89A + ++++ ++++ ++++ ++ +++ ++ ++ A167L + F360T 43 R89A + +++ +++ +++ + ++ + + V305M + F360I 44 R89A + +++ +++ +++ + ++ + + V305M + F360V 45 R89A + +++++ +++++ +++++ +++ +++++ +++ ++ V305M + F360T 46 R89A + ++++ ++ ++++ ++ +++ + + L327T + F360I 47 R89A + +++ ++ ++++ +++ ++ ++ + L327T + F360M 48 R89A + +++++ +++++ +++++ +++++ +++++ +++ + L327T + F360T 49 R89A + +++ ++++ ++++ +++ +++ ++ + I408R + F360M 50 R89A + +++++ +++++ +++++ +++++ +++++ +++ + I408W + F360V 51 R89A + +++ +++ +++ + ++ + + I408R + F360L 52 V165S + +++++ ++++ +++++ ++ +++ ++ + A167I + F360M 53 V165S + ++++ +++ ++++ + ++ + + A167C + F360L 54 V165C + ++++ +++ +++ ++ +++ + + A167L + F360T 55 V165C + +++++ +++++ +++++ ++ +++ ++ + V305M + F360I 56 V165C + +++++ +++++ +++++ ++ ++++ +++ + V305M + F360V 57 V165S + +++++ +++++ +++++ +++ +++++ +++ + V305L + F360L 58 V165C + +++++ ++++ +++++ ++ +++++ +++ + L327T + F360I 59 V165C + +++++ ++++ +++++ + +++++ +++ + L327T + F360V 60 V165S + ++++ ++++ +++++ +++ +++ ++ + L327T + F360T 61 V165C + ++++ ++++ ++++ +++ +++ ++++ + I408W + F360V 62 V165C + ++++ ++++ ++++ + +++ ++ + I408W + F360T 63 A167I + +++++ +++++ +++++ +++ +++++ +++ + V305M + F360L 64 A167C + ++++ +++++ +++++ + + ++ + V305L + F360V 65 A167L + ++++ +++++ +++++ +++ +++++ +++ + V305M + F360T 66 A167C + ++++ +++ ++++ ++ ++++ +++ + L327T + F360I 67 A167L + +++++ +++++ +++++ +++ +++++ +++ + L327T + F360M 68 A167I + +++++ +++++ +++++ +++ +++++ +++ + L327T + F360V 69 A167C + +++++ +++++ +++++ +++ +++++ +++ + I408W + F360I 70 A167I + ++++ ++++ ++++ + +++ ++ + I408W + F360V 71 A167L + ++++ ++++ ++++ +++ ++++ +++ + I408R + F360L 72 V305M + ++++ ++ ++++ + ++ ++ + L327T + F360I 73 V305L + +++++ +++ +++++ + ++ +++ + L327T + F360V 74 V305M + +++ +++ +++ ++ +++ ++ + L327T + F360T 75 V305M + +++++ +++++ +++++ +++ +++ +++ + I408W + F360I 76 V305M + +++++ +++++ +++++ +++ ++++ +++ + I408W + F360V 77 V305L + +++++ +++++ ++++ + ++ ++ + I408R + F360L 78 L327T + +++++ +++ +++++ ++ + +++ + I408R + F360M 79 L327T + +++++ +++++ +++++ +++++ ++++ +++++ ++ I408W + F360V 80 R89A + +++ +++ +++ ++ ++ + + V165C + A167C + F360I 81 R89A + +++++ +++++ +++++ +++ +++ ++ + V165S + V305M + F360M 82 R89A + +++ +++ ++++ + ++ + + V165C + L327T + F360V 83 R89A + ++++ ++++ ++++ ++ +++ ++ + V165S + I408R + F360L 84 R89A + +++ +++ ++ ++ ++ ++ + A167L + V305L + F360T 85 R89A + ++++ ++++ ++++ +++ ++++ +++++ ++ A167L + L327T + F360I 86 R89A + +++ +++ ++++ ++ ++ ++ + A167C + I408R + F360M 87 V165C + ++ ++ ++ + + + + A167I + V305M + F360V 88 V165S + ++++ ++++ ++++ ++ ++++ ++ + A167C + L327T + F360M 89 V165C + ++++ ++++ ++++ ++ +++ ++ + A167C + I408W + F360T 90 A167I + +++++ ++++ +++++ +++ ++++ +++ + V305L + L327T + F360V 91 A167L + +++++ +++++ +++++ +++ +++++ +++ + V305M + I408R + F360M 92 305L + +++++ +++++ +++++ +++ +++++ +++ + L327T + I408W + F360V
TABLE-US-00011 TABLE 10 CyPPO18 No. Variants Tiafenacil Saflufenacil Flumioxazin Fomesafen Sulfentrazone Oxyfluorfen Carfentrazone 1 R89A + ++++ ++++ ++++ +++ ++++ + ++ F360V 2 A167L + ++++ ++++ ++++ +++ ++++ + ++ F360I 3 V305M + ++++ ++++ ++++ ++++ ++++ ++ ++ F360I 4 L327T + ++++ +++ ++++ ++++ ++++ ++ ++ F360M 5 R89A + +++++ +++++ +++++ ++++ +++++ ++ ++ V165C + F360I 6 V165C + +++++ +++++ +++++ ++++ +++++ ++ ++ A167L + F360I 7 A167L + +++++ +++++ +++++ +++++ +++++ ++ ++ V305M + F360M 8 V165S + +++++ +++++ +++++ +++++ +++++ ++ ++ A167L + V305M + F360I 9 R89A + +++++ +++++ +++++ +++++ +++++ ++ ++ V165S + V305M + F360I 10 R89A + +++++ +++++ +++++ +++++ +++++ ++ ++ V165C + A167L + V305M + F360I
[0221] In Tables 9 and 10, the tolerance level of variants showing equivalent resistance to wild type was presented as ‘−’, and was done as ‘+’ per each 10-fold resistance until ‘+++++’ as maximal resistance.
[0222]
[0223] As shown in Tables 9 and 10 and
Example 4. Measurement of PPO Enzyme Activity and IC.SUB.50 .Value for Herbicides
[0224] The enzyme activities of variants wherein amino acids of certain position of PPO protein mutated were measured and inhibition assay with the PPO-inhibiting herbicides was conducted. Although the solubility of PPO protein is markedly low in aqueous condition, it was greatly increased when maltose binding protein (MBP) was fused to PPO protein. Thus, PPO proteins of wild type and variants were expressed as fused to MBP and were used for experiments (
[0225] In order to express wild type and variant proteins of CyPPO19 and CyPPO18 (refer to Examples 1 and 2), those genes were introduced into pMAL-c2× vector (refer to
[0226] The above transformed E. coli were cultured under the following conditions to express PPO proteins:
[0227] Induction: OD.sub.600=0.2, added with 0.3 mM IPTG (final concentration);
[0228] Culturing temperature: 23° C., with shaking at 200 rpm;
[0229] Culturing duration: 16 hrs;
[0230] Culturing volume: 200 ml/1,000 ml flask.
[0231] The cultured transformed E. coli cells were lysed and proteins were extracted as following:
[0232] Extraction buffer: Column buffer (50 mM Tris-Cl, pH 8.0, 200 mM NaCl) 5 ml buffer/g cell;
[0233] Sonication: SONICS & MATERIALS VCX130 (130 watts);
[0234] 15 sec ON, 10 sec OFF for 5 min on ice;
[0235] Centrifugation at 4° C. for 20 minutes (20,000×g);
[0236] The supernatant obtained after the centrifugation was diluted at the ratio of 1:6 with column buffer.
[0237] The following process for purification of PPO protein was performed in a 4° C. cold room. Amylose resin (New England Biolabs) was packed to 1.5×15 cm column (Bio-Rad, Econo Columns 1.5×15 cm, glass chromatography column, max. vol), and the obtained protein extracts were loaded to the column at a flow rate of 0.2 ml/min. The column was washed with 3 column volumes of buffer and the presence of protein in the washing solution was examined. When the protein was no longer detected, the washing procedure was terminated. Then, the MBP-PPO protein was eluted with approximately 2 column volumes of buffer containing 20 mM maltose. The protein concentration of each eluent was determined and the elution was stopped when the protein was no longer detected. Ten microliters of each fraction was investigated for protein quantification and SDS-PAGE analysis. The highly pure fractions of PPO protein variants were used for the enzyme assay.
[0238] Enzyme activities were measured with purified proteins above of wild type and variants of CyPPO19 and CyPPO18 as following:
[0239] Firstly, protoporphyrinogen IX was chemically synthesized in the laboratory. Overall process was performed under nitrogen stream. Six micrograms of protoporphyrin IX was dissolved in 20 ml of 20% (v/v) EtOH, and stirred under dark condition for 30 minutes. The obtained protoporphyrin IX solution was put into a 15 ml screw tube in an amount of 1,000 μl, and flushed with nitrogen gas for 5 minutes. To this, 1 g of sodium amalgam was added and vigorously shaken for 2 minutes. The lid was opened to exhaust hydrogen gas in the tube. Thereafter, the lid was closed and incubated for 3 minutes. The protoporphyrinogen IX solution was filtered using syringe and cellulose membrane filter. To 800 μl of the obtained protoporphyrinogen IX solution, approximately 1,600 μl of 2M MOPS [3-(N-morpholino) propanesulfonic acid] was added to adjust pH to 7.5. To determine the enzyme activity of PPO protein, a reaction mixture was prepared with the following composition (based on 10 ml): 50 mM Tris-Cl (pH 7.5); 50 mM NaCl; 0.04% (v/v) Tween 20; 40 mM glucose (0.072 g); 5 units glucose oxidase (16.6 mg); and 10 units catalase (1 μl).
[0240] Hundred and eighty microliters of a reaction mixture were placed in 96 well plates and 20 μl of the purified PPO protein (purified product of the MBP-fused PPO protein) above were added. After 50 μl of the mineral oil was layered, the reaction was initiated by adding the substrate, protoporphyrinogen IX solution, to a final concentration of 50 μM. The reaction proceeded at room temperature for 30 min and the fluorescence of protoporphyrin IX was measured using Microplate reader (Sense, Hidex) (excitation: 405 nm; emission: 633 nm). To calculate the PPO enzyme activity, the protoporphyrinogen IX solution was kept open in the air for more than 12 hours to oxidize the solution. To this, 2.7 N HCl was added, and the absorbance at 408 nm was measured. A standard curve was generated using standard protoporphyrin IX, and PPO activity was measured by calibration of protoporphyrin IX using the standard curve of protoporphyrin IX.
[0241] The concentration of the PPO-inhibiting herbicides that inhibits the PPO enzyme activity by 50% (IC.sub.50) was measured for each herbicide. The final concentrations of each herbicide were as follows: [0242] Concentrations of tiafenacil, saflufenacil, fomesafen, flumioxazin, sulfentrazone, oxyfluorfen, and carfentrazone: 0, 10, 50, 100, 250, 500, 1,000, 2,500, 5,000, 10,000 nM
[0243] The IC.sub.50 value, the concentration of the herbicide inhibiting the PPO enzyme activity to 50%, was calculated by adding the herbicide of the above concentrations to the reaction mixture.
[0244] The IC.sub.50 values for each herbicide are shown in the following Tables 11 and 12.
TABLE-US-00012 TABLE 11 IC.sub.50 values (nM) of CyPPO19 wild type and variants against various herbicides CyPPO19 WT IC.sub.50 (nM) and variants Tiafenacil Saflufenacil Flumioxazin Fomesafen Sulfentrazone Oxyfluorfen Carfentrazone WT 67 158 55 242 516 570 763 1 R89A 113 616 163 2,364 1,384 602 857 2 V165C 186 280 159 330 2,545 3,215 3,094 3 V165S 269 277 225 348 1,213 1,667 10,000 4 A167C 342 395 197 843 2,240 649 3,527 5 A167I 248 799 154 899 3,521 1,331 10,000 6 A167L 597 10,000 10,000 1,755 10,000 5,261 10,000 7 V305M 392 435 437 257 693 732 910 8 V305L 1,135 1,132 367 466 806 793 1,329 9 L327T 2,614 761 2,599 1,035 10,000 8,612 10,000 10 F360M 1,328 328 1,198 584 10,000 4,895 2,507 11 F360I 4,863 1,109 10,000 492 10,000 928 10,000 12 F360L 4,385 10,000 3,865 851 10,000 754 10,000 13 F360V 4,791 10,000 10,000 391 10,000 638 10,000 14 F360T 10,000 10,000 10,000 10,000 10,000 10,000 10,000 15 I408R 1,039 10,000 696 2,097 10,000 10,000 10,000 16 I408W 3,001 10,000 10,000 10,000 10,000 10,000 10,000 17 R89A + 3,751 10,000 2,090 10,000 10,000 5,291 6,192 F360M 18 V165C + 10,000 10,000 7,763 10,000 10,000 5,266 10,000 F360M 19 V165S + 10,000 10,000 10,000 936 10,000 2,070 10,000 F360V 20 A167C + 10,000 10,000 10,000 871 10,000 6,011 10,000 F360I 21 A167I + 10,000 10,000 10,000 1,248 10,000 10,000 10,000 F360L 22 A167L + 10,000 10,000 10,000 3,151 10,000 10,000 10,000 F360M 23 V305M + 10,000 10,000 3,104 1,077 10,000 5,044 10,000 F360M 24 L327T + 10,000 1,618 10,000 2,266 10,000 10,000 10,000 F360M 25 V165C + 10,000 10,000 10,000 988 10,000 10,000 10,000 A167C + F360I 26 V165S + 10,000 10,000 10,000 7,003 10,000 10,000 10,000 A167L + F360M 27 R89A + 10,000 10,000 10,000 10,000 10,000 10,000 10,000 L327T + F360M 28 V165C + 10,000 10,000 10,000 10,000 10,000 10,000 10,000 L327T + F360I 29 A167I + 10,000 10,000 10,000 10,000 10,000 10,000 10,000 L327T + F360V 30 V305L + 10,000 10,000 10,000 10,000 10,000 10,000 10,000 L327T + F360M 31 L327T + 10,000 10,000 10,000 10,000 10,000 10,000 10,000 I408W + F360V
TABLE-US-00013 TABLE 12 IC.sub.50 values (nM) of CyPPO18 wild type and variants against various herbicides CyPPO18 WT IC.sub.50 (nM) and variants Tiafenacil Saflufenacil Flumioxazin Fomesafen Sulfentrazone Oxyfluorfen Carfentrazone WT 18 32 13 629 27 103 566 1 R89A 98 1,231 106 2,853 1,566 491 872 2 V165C 95 182 29 1,739 104 502 1,217 3 V165S 119 89 62 1,305 185 1,487 2,229 4 A167C 94 435 65 1,209 762 570 1,882 5 A167L 813 1,933 1,288 2,681 649 2,812 4,015 6 A167I 672 1,326 231 1,377 792 2,004 2,602 7 V305M 177 132 107 1,251 254 355 1,613 8 L327T 233 89 108 1,789 256 3,599 723 9 F360M 130 1,618 99 1,646 118 329 2,181 10 F360I 822 4,093 3,287 3,711 203 455 3,928 11 F360L 195 5,000 1,188 2,712 356 538 2,512 12 F360V 336 5,000 882 1,934 175 299 4,237 13 R89A + 1,002 5,000 1,288 5,000 5,000 5,000 5,000 F360M 14 A167L + 5,000 5,000 5,000 5,000 5,000 5,000 5,000 F360M 15 L327T + 5,000 1,662 3,841 5,000 855 5,000 5,000 F360M 16 V165C + 5,000 5,000 5,000 5,000 4,483 5,000 5,000 A167L + F360M 17 V165S + 5,000 5,000 5,000 5,000 5,000 5,000 5,000 A167C + L327T + F360M 18 R89A + 5,000 5,000 5,000 5,000 5,000 5,000 5,000 V165S + A167C + L327T + F360M
[0245] (In the above Tables 11 and 12, IC.sub.50 value ‘5,000’ or IC.sub.50 value ‘10,000’ means equivalent to or higher than IC.sub.50 value of 5,000 or IC.sub.50 value of 10,000 because the enzyme activity was not inhibited by 50% even at each herbicide concentration of 5,000 nM or 10,000 nM)
[0246] As shown in the Tables 11 and 12, it was demonstrated that variants of CyPPO proteins showed the significantly increased IC.sub.50 values against each herbicide compared to the wild type. Such results indicate that herbicide tolerance was increased by amino acid substitutions at specified positions of PPO protein. Although the data showed that CyPPO protein variants possess reduced enzyme activity compared to the wild type, it might be caused by the difference of protein folding and hydrophobicity between proteins. Plant-originated PPO protein is localized in the chloroplast membrane and hydrophobic, however recombinant PPO protein fused to MBP is hydrophilic. Therefore, when PPO variants are properly assembled and expressed in plant chloroplasts, the enzyme activity would not be different between variants and wild type drastically.
Example 5. PPO Protein Variants Originated from Various Cyanobacteria, Algae, or Bacteria
[0247] Based on the mutation positions of CyPPO19 and CyPPO18 whose effect on resistance increase was verified in the examples 3 and 4 above, the mutation sites of PPO proteins originated from various cyanobacteria, algae, or bacteria which have similar effect on herbicide resistance to variants of CyPPO19 and CyPPO18 were analyzed via the analysis of their 3D protein structure and are listed in Table 13:
TABLE-US-00014 TABLE 13 SEQ Amino acid after Mutated Site ID mutation (substitution) 1 2 3 4 5 6 NO at the mutated site A C or S C, I, or L M or L T M, I, L, T, or V Accession No. 1 Thermosynechococcus R89 V165 A167 V305 L327 F360 CP032152.1 elongatus PKUAC-SCTE542 2 Cyanobacteria R89 V165 A167 V305 L327 F360 RMH63851.1 bacterium J003 3 Thermosynechococcus R89 V165 A167 V305 L327 F360 BAY51976.1 vulcanus NIES-2134 4 Synechococcus R92 V168 A170 V312 L334 F367 WP_099798264.1 lividus 5 Microcoleaceae R93 V174 A176 V319 L341 Y374 HBK97224.1 bacterium UBA10368 6 Microcoleaceae R87 V168 A170 V313 L335 Y368 HAT14741.1 bacterium UBA11344 7 Oscillatoriales R92 V173 A175 V327 L349 Y382 TAE85894.1 cyanobacterium (TAE85894.1) 8 Cyanobacteria R92 V166 A168 V309 L331 F364 HAN47127.1 bacterium UBA8156 9 Rubidibacter R86 V160 A162 V309 L331 F364 WP_022605844.1 lacunae 10 Hydrocoleum sp. R92 V171 A173 V317 L339 F372 WP_094676324.1 CS-953 11 Oscillatoriales R92 V173 A175 V327 L349 Y382 TAE55813.1 cyanobacterium (TAE55813.1) 12 Crinalium R85 V166 A168 V312 L334 F367 WP_015202233.1 epipsammum 13 Oscillatoriales R92 V173 A175 V327 L349 Y382 TAE70643.1 cyanobacterium (TAE70643.1) 14 Oscillatoriales R92 V173 A175 V327 L349 Y382 TAE14532.1 cyanobacterium (TAE14532.1) 15 Cyanobacteria R85 V166 A168 V312 L334 F367 PSP16006.1 bacterium QS_8_64_29 16 Lyngbya aestuarii R93 V174 A176 V320 L342 Y375 WP_023067908.1 17 Tychonema R93 V174 A176 V319 L341 F374 WP_096831359.1 bourrellyi 18 Oscillatoriales R93 V174 A176 V319 L341 Y374 TAG91209.1 cyanobacterium (TAG91209.1) 19 Cyanobacteria R85 V160 A162 V308 L330 F363 PSO49761.1 bacterium SW_9_44_58 20 Trichodesmium R92 V173 A175 V319 L341 Y374 WP_011611816.1 erythraeum 21 Geitlerinema sp. R105 V180 A182 V332 L355 F388 WP_071516524.1 PCC 9228 22 Oscillatoriales R104 V185 A187 V334 L356 F389 TAD79992.1 cyanobacterium (TAD79992.1) 23 Oscillatoriales R93 V174 A176 V319 L341 Y374 TAD82603.1 cyanobacterium (TAD82603.1) 24 Oscillatoriales R93 V174 A176 V319 L341 Y374 TAD95528.1 cyanobacterium (TAD95528.1) 25 Limnothrix sp. R88 V169 A171 V318 L340 F373 WP_099534595.1 PR1529 26 Planktothricoides R102 V183 A185 V329 L352 F385 WP_054468037.1 sp. SR001 27 Limnothrix sp. R88 V169 A171 V318 L340 F373 RFP59749.1 CACIAM 69d 28 Okeania hirsuta R92 V172 A174 V318 L340 F373 WP_124155207.1 (WP_124155207.1) 29 Okeania hirsuta R92 V172 A174 V318 L340 F373 WP_124145785.1 (WP_124145785.1) 30 Desertifilum sp. R96 V177 A179 V324 L346 Y379 WP_069967861.1 IPPAS B-1220 31 Synechococcus sp. R105 V179 A181 V322 L344 F377 PIK93057.1 65AY6Li 32 Synechococcus sp. R105 V179 A181 V322 L344 F377 PIK88626.1 65AY6A5 33 Synechococcus sp. R105 V179 A181 V322 L344 F377 PIK94415.1 60AY4M2 34 Synechococcus sp. R105 V179 A181 V322 L344 F377 PIK96673.1 63AY4M1 35 Synechococcus sp. R105 V179 A181 V322 L344 F377 PIK85371.1 63AY4M2 36 Cyanobacteria R100 V177 A179 V323 L345 F378 RMH78328.1 bacterium J007 37 Spirulina major R85 V166 A168 V311 L333 F366 WP_072619201.1 38 Euhalothece sp. R85 V160 A162 V306 L328 F361 PNW65677.1 KZN 001 39 Dactylococcopsis R85 V160 A162 V306 L328 F361 WP_015230904.1 salina 40 Synechococcus sp. R89 V163 A165 V306 L328 Y361 WP_017328280.1 PCC 7336 41 Arthrospira sp. R93 V174 A176 V320 L342 Y375 WP_111891435.1 O9.13F 42 Arthrospira R93 V174 A176 V320 L342 Y375 WP_006622155.1 platensis (WP_006622155.1) 43 Arthrospira R93 V174 A176 V321 L343 Y376 WP_006617829.1 platensis (WP_006617829.1) 44 Pseudanabaena sp. R98 V172 A174 V318 L340 F373 WP_103669271.1 BC1403 45 Pseudanabaena sp. R97 V171 A173 V316 L338 F371 WP_055076288.1 ‘Roaring Creek’ 46 Pseudanabaena sp. R98 V172 A174 V319 L341 F374 HBC40803.1 (HBC40803.1) 47 Synechococcus sp. R106 V180 A182 V343 L365 F398 WP_049749573.1 JA-2-3B′a(2-13) 48 Pseudanabaena R97 V171 A173 V317 L339 F372 WP_009629673.1 biceps 49 Pseudanabaena sp. R98 V172 A174 V318 L340 F373 PZV12410.1 (PZV12410.1) 50 Pseudanabaena sp. R104 V178 A180 V336 L358 F391 WP_015165508.1 PCC 7367 51 Pseudanabaena sp. R98 V172 A174 V319 L341 F374 WP_094530677.1 SR411 52 Pseudanabaena R98 V172 A174 V318 L340 F373 PZO41121.1 frigida 53 Pseudanabaena sp. R99 V173 A175 V320 L342 F375 PZU98053 (PZU98053) 54 Oscillatoriales R106 V180 A182 V327 L349 F382 OIP76421.1 cyanobacterium CG2_30_44_21 55 Chlamydomonas R167 V241 A243 V389 L418 Y451 AF068635.1 reinhardtii 56 Volvox carteri f. R168 V242 A244 V389 L418 Y451 XM_002955148.1 nagariensis 57 Chondrus crispus R106 V181 A183 V328 L350 Y383 XM_005718155.1 (CHC_T00000813001) 58 Galdieria R167 V242 A244 V399 L421 Y454 XM_005708373.1 sulphuraria 59 Pseudanabaena sp. R98 V172 A174 V319 L341 F374 WP_126386150.1 ABRG5-3 60 Arthrospira R93 V174 A176 V321 L343 Y376 WP_014277531.1 platensis YZ 61 Gloeobacter R94 V167 A169 V301 L323 F356 WP_023175091 kilaueensis JS1 62 Gloeobacter R91 M164 A166 V298 L320 F353 WP_011140945 violaceus PCC 7421 63 Panicum hallii var. R145 V219 A221 V366 L394 Y427 PUZ57154.1 hallii 64 Porphyra R157 V232 A234 V381 L403 Y436 OSX75961.1 umbilicalis 65 Ostreococcus tauri R124 V198 A200 V349 L380 Y415 XP_003079975.1 66 Ectocarpus R144 V220 A222 V374 L396 Y429 CBJ31610.1 siliculosus 67 Nannochloropsis R87 V162 A164 V311 L333 Y365 XM_005854685.1 gaditana CCMP526 68 Ostreococcus R67 V141 A143 V288 L319 Y354 XM_001418241.1 lucimarinus CCE9901 69 Guillardia theta R159 V233 A235 V381 L414 Y447 XM_005821253.1 CCMP2712 70 Cyanidioschyzon R168 V259 A261 V413 L435 Y468 XM_005535077.1 merolae strain 10D 71 Bathycoccus R152 V227 A229 V378 L409 Y444 XM_007513261.1 prasinos 72 Myxococcus R94 I168 A170 I311 L332 M365 AY916795.1 Xanthus Synthetic construct 73 Myxococcus R94 I168 A170 I310 L331 M364 WP_090484749.1 virescens 74 Myxococcus R86 I159 A161 I304 L325 M358 ATB45699.1 macrosporus DSM 14697 75 Myxococcus R94 I168 A170 I310 L331 M364 WP_044889345.1 hansupus 76 Myxococcus R85 I159 A161 I305 L326 M359 WP_046711394.1 fulvus 77 Myxococcus R85 I159 A161 I305 L326 M359 WP_074949681.1 fulvus 78 Myxococcus R85 I159 A161 I303 L324 M357 WP_015346914.1 stipitatus 79 Hyalangium A86 I160 A162 I305 L326 M359 WP_044193071.1 minutum
Example 6. Generation of Arabidopsis thaliana Transformants Using CyPPOs and Variants, and PPO-Inhibiting Herbicide Tolerance Test
[0248] 6-1. Construction of A. thaliana Transformation Vectors and Generation of A. thaliana Transformants
[0249] A. thaliana was transformed with a binary vector having ORF of a selectable marker, Bar gene (glufosinate-tolerant gene), and ORF of each variant gene of CyPPO19 and CyPPO18. The transgenic plant was examined for cross-tolerance towards glufosinate and PPO-inhibiting herbicides. The bar gene was also used to examine whether the transgene was stably inherited during generations. NOS promoter and E9 terminator were used for bar gene expression.
[0250] In order to express proteins of CyPPO19, CyPPO19 variants, CyPPO18, and CyPPO18 variants in plants, a CaMV35S promoter and a NOS terminator were used. Encoding genes of CyPPO19, CyPPO19 variants, CyPPO18, and CyPPO18 variants were amplified by using PCR with primer pairs in Table 14, and then introduced into binary vector using XhoI and BamHI restriction enzymes.
TABLE-US-00015 TABLE 14 Primer sequence SEQ ID Primer Sequence (5′.fwdarw.3′) NO CyPPO19_XhoI_F CTCGAGATGTCTGAGGTGGACGTT 297 GCC CyPPO19_BamHI_R GGATCCAGGTTGGCCCCCGGAAAG 298 ATA CyPPO18_XhoI_F CTCGAGATGATTGAAGTGGATGTG 299 GCT CyPPO18_BamHI_R GGATCCTGATTGTCCACCAGCGAG 300
[0251] Furthermore, for confirmation of the protein expression, hemagglutinin (HA) tag was fused to the 3′-terminal region of PPO protein coding gene using BamHI and Sad restriction enzymes. A NOS terminator was inserted to 3′-terminus of HA tag, to induce transcription termination of PPO gene. In addition, in order to transit protein to chloroplast, transit peptide (TP) gene (SEQ ID NO: 301) of AtPPO1 gene (SEQ ID NO: 302) was fused to 5′-terminal region of PPO protein coding gene using XbaI and XhoI restriction enzymes.
[0252] Each constructed vector was transformed to Agrobacterium tumefaciens GV3101 competent cell by freeze-thaw method. Agrobacterium GV3101 competent cells were prepared by following procedures, Agrobacterium GV3101 strain was cultured in 5 ml LB media at 30° C., 200 rpm for 12 hrs. The cells were subcultured in 200 ml of LB media at 30° C., 200 rpm for 3 to 4 hrs, and centrifuged at 3,000×g at 4° C. for 20 minutes. The cell pellet was washed with sterile distilled water, and then resuspended in 20 ml of LB media. Snap frozen 200 μl aliquots with liquid nitrogen were stored in a deep freezer.
[0253] Each transformed Agrobacterium was screened in spectinomycin-containing LB media. The screened colony was cultured in LB broth. After Agrobacterium cell was harvested from the culture media, it was resuspended in the solution containing 5% sucrose (w/v) and 0.05% Silwet L-77 (v/v) (Momentive Performance Materials Co., Ltd.) at an absorbance (OD.sub.600) of 0.8. By floral dipping method, A. thaliana wild type (Col-0) was transformed, and then the seeds (T.sub.1) were harvested after 1 to 2 months.
[0254] Transgenic plants were screened with glufosinate tolerance which was conferred by Bar gene expression in the binary vector. The obtained T.sub.1 seeds were shown in ½ MS media (2.25 g/l MS salt, 10 g/l sucrose, 7 g/l Agar) supplemented with 50 μM glufosinate, and the surviving plants were selected 7 days after sowing. They were, then, transplanted into soil and grown to obtain T.sub.1 plants.
[0255] In order to examine PPO-inhibiting herbicide tolerance of the transgenic plants, 3 to 4-week-old plants were evenly sprayed with herbicide (100 ml of 1 μM tiafenacil and 0.05% Silwet L-77 (v/v)) in 40×60 cm area (0.24 m.sup.2). While wild type A. thaliana (Col-0) completely died within 7 days after treatment of tiafenacil at the same concentration, each transgenic plant showed to PPO-inhibiting herbicide treatment and survived.
[0256] The T.sub.2 seeds were harvested from tolerant and surviving T.sub.1 transgenic plants and were shown to ½ MS media (2.25 g/l MS salt, 10 g/l sucrose, 7 g/l Agar) supplemented with 50 μM glufosinate. One week later, surviving plants were transplanted to soil.
[0257] 6-2. Verification of Herbicide Tolerance of Transformed Arabidopsis Plants (T.sub.2)
[0258] Arabidopsis plants (T.sub.2) transformed with genes including CyPPO19, CyPPO19 variants (F360M, F360V, F360L, V165C+F360M, V165S+F360V), CyPPO18, or CyPPO18 variant (L327T+F360M) were tested for their tolerance against herbicides.
[0259] In order to examine PPO-inhibiting herbicide tolerance of the transgenic plants, transgenic plants of CyPPO19 WT and its variants (F360M, F360V, F360L, V165C+F360M, V165S+F360V) were evenly sprayed with herbicide (100 ml of 1 μM tiafenacil and 0.05% Silwet L-77 (v/v))/(100 ml of 1 μM flumioxazin and 0.05% Silwet L-77 (v/v)) in 40×60 cm area (0.24 m.sup.2). Herbicide tolerance was evaluated 7 days after treatment. Wild type Arabidopsis plant (Col-0) was used as a control.
[0260] The tolerance evaluation of transgenic Arabidopsis (T.sub.2) plants after 1 μM tiafenacil or 1 μM flumioxazin treatment was shown in
[0261] In order to examine PPO-inhibiting herbicide tolerance of the transgenic plants, transgenic plants of CyPPO19 variants (F360M, F360V, F360L, V165C+F360M, V165S+F360V) were evenly sprayed with herbicide (100 ml of 5 μM tiafenacil and 0.05% Silwet L-77 (v/v))/(100 ml of 5 μM flumioxazin and 0.05% Silwet L-77 (v/v)) in 40×60 cm area (0.24 m.sup.2). Herbicide tolerance was evaluated 7 days after treatment. Wild type Arabidopsis plant (Col-0) was used as a control.
[0262] The tolerance evaluation of transgenic Arabidopsis (T.sub.2) plants after 5 μM tiafenacil or 5 μM flumioxazin treatment was shown in
[0263] In order to examine PPO-inhibiting herbicide tolerance of the transgenic plants, transgenic plants of CyPPO18 wild type were evenly sprayed with herbicide (100 ml of 1 μM tiafenacil and 0.05% Silwet L-77 (v/v)) in 40×60 cm area (0.24 m.sup.2). Herbicide tolerance was evaluated 7 days after treatment. Wild type Arabidopsis plant (Col-0) was used as a control.
[0264] The tolerance evaluation of transgenic Arabidopsis (T.sub.2) plants after 1 μM tiafenacil treatment was shown in
[0265] In order to examine PPO-inhibiting herbicide tolerance of the transgenic plants, transgenic plants of CyPPO18 variant (L327T+F360M) were evenly sprayed with herbicide (100 ml of 1 μM tiafenacil and 0.05% Silwet L-77 (v/v)) in 40×60 cm area (0.24 m.sup.2). Herbicide tolerance was evaluated 7 days after treatment. Wild type Arabidopsis plant (Col-0) was used as a control.
[0266] The tolerance evaluation of transgenic Arabidopsis (T.sub.2) plants after 1 μM tiafenacil treatment was shown in
[0267] Based on the results shown in
TABLE-US-00016 TABLE 15 Injury index definition Injury index Symptom 1 1 0 No damage 1 Dried leaf tip 2 Over 20% and less than 30% of the plant was scorched 2.5 Over 30% and less than 50% of the plant was scorched 3 Over 50% and less than 70% of the plant was scorched 4 Over 70% of the plant was scorched 5 The whole plant was dried and died
[0268] The tolerance levels of transgenic plants were evaluated according to the injury index definition and were shown in Tables 16 to 19.
TABLE-US-00017 TABLE 16 Injury index of transgenic plants of CyPPO19 WT and its variants (F360M, F360V, F360L, V165C + F360M, V165S + F360V) after 1 μM tiafenacil or 1 μM flumioxazin treatment Injury index 1 μM tiafenacil 1 μM flumioxazin Col-0 5 5 CyPPO19 WT 3 2 CyPPO19 F360M 0-1 0-1 CyPPO19 F360V 0-1 0-1 CyPPO19 F360L 1 1 CyPPO19 0-1 0-1 V165C + F360M CyPPO19 V165S + F360V 0-1 0-1
TABLE-US-00018 TABLE 17 Injury index of transgenic plants of CyPPO19 variants (F360M, F360V, F360L, V165C + F360M, V165S + F360V) after 5 μM tiafenacil or 5 μM flumioxazin treatment Injury index 5 μM tiafenacil 5 μM flumioxazin Col-0 5 5 CyPPO19 F360M 1 1 CyPPO19 F360V 0-1 0-1 CyPPO19 F360L 1 1 CyPPO19 V165C + F360M 0-1 0-1 CyPPO19 V165S + F360V 0-1 0-1
TABLE-US-00019 TABLE 18 Injury index of transgenic plants of CyPPO18 WT after 1 μM tiafenacil treatment Injury index 1 μM tiafenacil Col-0 5 CyPPO18 WT 3-4
TABLE-US-00020 TABLE 19 Injury index of transgenic plants of CyPPO18 variant (L327T + F360M) after 1 μM tiafenacil treatment Injury index 1 μM tiafenacil Col-0 5 CyPPO18 L327T + F360M 0-1
[0269] As demonstrated by the above results, transgenic plants transformed with CyPPO19 WT or CyPPO18 WT exhibit increased herbicide tolerance compared to non-transgenic plants. In addition, transgenic plants transformed with CyPPO19 variants or CyPPO18 variant exhibit significantly increased herbicide tolerance compared to non-transgenic plants.