1050 results about "Point mutation" patented technology

The invention provides a carbonyl reductase mutant. The carbonyl reductase mutant is obtained by performing single-point mutation or multi-point combined mutation on the 17th site, the 40th site and the 64th site of an amino acid sequence as shown in SEQ ID NO.1. The invention also provides a coding gene, a recombinant vector containing the coding gene, a co-expression engineering bacterium and an application of the co-expression engineering bacterium. Compared with a wild type enzyme, the carbonyl reductase mutant has high activity and high stereoselectivity, the enzyme activity can reach more than two times that of the wild type enzyme, the catalytic efficiency on a substrate precursor ketone is remarkably improved, the yield of a statin drug intermediate and chiral alcohol synthesized by an enzyme method of the carbonyl reductase mutant is remarkably improved, and the yield of a rosuvastatin intermediate (3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R, 3R) is remarkably improved. The highest yields of the (3R, 5R)-6-chloro-3, 5-dihydroxyhexanoic acid tert-butyl ester and the atorvastatin intermediate (3R, 5R)-6-cyano-3, 5-dihydroxyhexanoic acid tert-butyl ester reach 99% and 97.6% respectively, e.e. Is larger than 99%, and the method has high industrial application value.

The invention discloses a carbonyl reductase, a mutant and an application of the carbonyl reductase in synthesis of a chiral alcohol compound. The carbonyl reductase mutant is obtained by performing single-site or multi-site mutation on the 96th site, the 145th site, the 202nd site or the 206th site of the amino acid sequence of the carbonyl reductase LbCR derived from lactobacillus brevis as shown in SEQ ID No.2. The activity and stability of the carbonyl reductase LbCR mutant are obviously improved, and the carbonyl reductase LbCR mutant has a wide substrate spectrum. Compared with a wild type, the mutant LbCRM4 has the advantages that the enzyme activity is improved by 86.3 times, the substrate conversion rate is greater than 99%, the e.e.p value of the product is always kept at 99.5% or above, the space time yield reaches 1288.9 g / L / d, and the half-life period at 40 DEG C is 101.4 h and is improved by 83.5 times. The LbCR mutant has an industrial application prospect.

The invention discloses polyketide synthase or a polyketide synthase mutant and application thereof, and belongs to the technical field of gene engineering. The polyketide synthase is AspiPKS4, AspiPKS5, AspiPKS6 and AspiPKS7 from cyathea spinulosa, FhPKS2, FhPKS3, FhPKS4, FhPKS5 and FhPKS6 from ficus himalayana, and CrPKS from floating fern. The mutant is obtained by carrying out single point mutation on the second amino acid of AspiPKS7 or deleting an N-terminal redundant sequence. The polyketide synthase or the mutant is used for replacing NnHisspS in an original FBP luminescence system, and the biological self-luminescence level can be remarkably improved. The invention further provides a simplified and improved FBP system which comprises the polyketide synthase or the polyketide synthase mutant, CPH, H3H and Luz, and the application convenience and the application luminescence capacity of the FBP system are improved.

The invention relates to the technical field of bioengineering, and discloses a mutant of Burkholderia lipase as well as a recombinant expression vector and application of the mutant, the mutant comprises P131S, T132A, T251A, T251S, P131A, P131Q, T132G, Q88S and P113A single processes; and a Q88S double process and a P113A double process; and a multi-site mutation combination: a combination I: Q88S, P113A, T132G and L287S, and a combination II: Q88S, P113A, T132G and L287S; a combination II: Q88S, P113A, P131S and L287S; and a combination III: Q88S, P113A, P131S and T251A. Based on experiments, the invention finds that each mutant can not only improve the protein yield, but also improve the enzyme activity by 57% at most; ePA enrichment experiments find that the EPA content of the mutant can be increased by 33% at most, and the mutant has excellent EPA purification and enrichment effects.

The invention discloses a glycosyl transferase mutant and an application of the glycosyl transferase mutant in synthesis of rebaudioside. According to the invention, single-point mutation and multi-point mutation are carried out on the basis of a glycosyl transferase amino acid sequence as shown in SEQ ID NO: 1, and a mutant with improved catalytic activity is obtained. The catalytic activity, the substrate specificity and / or the substrate specificity of the glycosyl transferase mutant are / is changed, and the catalytic activity of enzyme to a specific substrate can be remarkably improved by mutation at a specific site. And carrying out induced expression and protein purification on the obtained mutation sequence to obtain the mutant enzyme. The mutant enzyme is used as a catalyst, and UDPG is used as a glycosyl donor, so that the catalytic reaction efficiency of substrates such as stevioside ST, rebaudioside A (RebA) and rebaudioside D (RebD) can be obviously improved. According to the glycosyl transferase UGT76G1 mutant constructed by the research, the catalytic activity of the glycosyl transferase UGT76G1 mutant is improved, and efficient production of rebaudioside M is realized by optimizing a reaction system.

The invention discloses a hemoglobin-resistant Taq DNA polymerase mutant and a construction method thereof, and relates to the field of biology, and the hemoglobin-resistant Taq DNA polymerase mutant is characterized in that a nucleotide sequence for coding the Taq DNA polymerase is shown as SEQ ID NO.1, and the mutant comprises at least one mutation or all mutations selected from S623D and E721A sites. On the basis of natural Taq DNA polymerase, the molecular structure of the Taq DNA polymerase is modified through rational design and combination with a site-specific mutagenesis biotechnology, so that the Taq DNA polymerase mutant is more suitable for PCR amplification of samples containing hemoglobin and the like than a wild type, and the result judgment accuracy of a sample containing a hemoglobin inhibitor is more facilitated.

The invention discloses a thermostable conjugated polyketoreductase mutant, which is obtained by performing single-point mutation or multi-point combined mutation on the 25th site, the 92th site, the 214th site or the 256th site of an amino acid sequence as shown in SEQ ID NO.1. The invention further discloses a preparation method of the thermostable conjugated polyketoreductase mutant. The initial enzyme activity of the mutant is high, and the residual enzyme activity is gt after incubation at 50 DEG C; the Tm value can be increased by more than 9 DEG C compared with that of an original strain, the 50 DEG C half-life period t1 / 2 is increased by more than 377.8 times, and the thermal stability is obviously improved. The invention also provides a coding gene, a recombinant vector containing the coding gene and a co-expression engineering bacterium. The thermostable conjugated polyketoreductase mutant, glucose dehydrogenase and L-pantolactone dehydrogenase are used for constructing a three-enzyme co-expression engineering bacterium as a biocatalyst, racemization pantolactone is catalyzed to synthesize DPL, for a 1M substrate, the yield of the DPL reaches 97.5% within 36 hours, KPL hydrolysis is avoided, the reaction time is shorter, the product concentration is higher, and the thermostable conjugated polyketoreductase mutant has great market application value.

The invention relates to the technical field of gene engineering and enzyme engineering, in particular to an esterase mutant for degrading ethyl carbamate and application of the esterase mutant, the esterase mutant has an amino acid sequence as shown in SEQ ID NO.1 which is subjected to site mutation, the site mutation is any one or more site combined mutation of V129S, V161L or I229M, and the amino acid sequence of the esterase mutant is shown in SEQ ID NO.1. The V129S site mutation is that valine at the 129 site is mutated into serine, the V161L site mutation is that valine at the 161 site is mutated into leucine, and the I229M site mutation is that isoleucine at the 229 site is mutated into methionine. Mutation is carried out through a site-directed mutagenesis method, so that the amino acid sequence of the esterase mutant V129S / I229M is changed, the autoplasmic structure and function of eggs are changed, the esterase mutant V129S / I229M with the ethyl carbamate hydrolysis rate increased to 6.55 times in an acid environment is finally obtained, and the esterase mutant V129S / I229M has high industrial application value.

The invention relates to the technical field of synthetic biology and microbial fermentation, in particular to a 5-aminolevulinic acid synthetase mutant and application thereof. According to the invention, 5-aminolevulinic acid synthetase derived from rhodobacter capsulatus is expressed in recombinant Escherichia coli, point mutation is carried out on non-conservative amino acid of wild-type ALAS to obtain I86C mutants, the enzymatic activity of the 5-aminolevulinic acid synthetase is improved, and the ability of the 5-aminolevulinic acid synthetase in synthesis of 5-aminolevulinic acid is improved. The method can be used for solving the problems that the enzyme activity of the ALAS is low and the activity of the ALAS is easily inhibited by high-concentration substrate glycine and the like at present, and the yield of the 5-ALA is increased.

The invention provides a molecular marker related to immune traits of elephant male semi-fine wool sheep and a detection primer and application thereof, and belongs to the technical field of molecular assisted breeding. The nucleotide sequence of the molecular marker is shown as SEQ ID NO.1; the molecular marker comprises an SNP site, the SNP site is located at the 117th site of the molecular marker, the mutation basic group of the SNP site is A or G, and the immune globulin content of an individual male semi-fine wool sheep with the genotype of AG or GG at the SNP site is remarkably higher than that of an individual with the genotype of AA. The content of immune globulins IgA, IgG and IgM of an individual elephant male semi-fine-wool sheep can be judged according to the genotype of the molecular marker, the immune traits of the elephant male semi-fine-wool sheep can be rapidly and accurately evaluated, the high-immunity elephant male semi-fine-wool sheep can be screened, the molecular marker has important significance on early-stage auxiliary breeding of the elephant male semi-fine-wool sheep, the breeding period is remarkably shortened, and the breeding cost is reduced. The breeding efficiency is improved.

The invention discloses a high-efficiency lysine decarboxylase mutant and an application of the high-efficiency lysine decarboxylase mutant in synthesis of pentamethylene diamine. A series of mutants including a single mutant (such as N218G, T222V, C244P and the like), a double mutant and a three mutant are obtained by carrying out multi-site mutation on wild type lysine decarboxylase (SEQ ID NO.2) from Klebsiella grimontii. The catalytic efficiency of the mutant is remarkably improved, and the activity of the mutant is improved by 5.0-10.2 times compared with that of a wild type enzyme. According to the method disclosed by the invention, the substrate conversion rate of 99% or above can be realized within 2 hours through an optimized process of constructing an expression vector and a genetically engineered bacterium, inducing expression of lysine decarboxylase and synthesizing 1, 5-pentanediamine by utilizing a whole-cell catalysis technology. Compared with a traditional chemical method and a natural enzyme method, the method disclosed by the invention has the advantages of simplified process, high catalytic efficiency, low production cost and the like, and is suitable for producing bio-based 1, 5-pentamethylene diamine and nylon 56 salt.

The invention discloses a grass carp gamma interferon fusion protein as well as a mutant, a coding gene and application thereof. In order to improve the expression quantity or expression efficiency of the grass carp gamma interferon, codon optimization and mutation are carried out on the coding gene of the grass carp gamma interferon to obtain the grass carp gamma interferon mutant. The fusion protein is further obtained by connecting the grass carp gamma interferon mutant with the C end of the grass carp ferritin heavy chain subunit of which the last 17 amino acids are removed through a connecting peptide. In order to further improve the antiviral activity of the fusion protein, the obtained fusion protein is subjected to single-point mutation, and the titer of the fusion protein is remarkably improved. The fusion protein is expressed by a silkworm cell eukaryotic expression system, and the fusion protein shows a conformation suitable for the interferon to play functions based on the ferritin self-assembly characteristic, so that the titer of the interferon in a host is effectively improved, and the in-vivo and in-vitro half-life period of the interferon is prolonged. The invention has application prospects in preparation of drugs or reagents for preventing or treating viral diseases of grass carp and the like.

The invention relates to the technical field of high-throughput sequencing, and discloses a kit and a library construction method and a target variation detection and analysis method thereof, the kit comprises a pre-library construction reagent and a target region liquid phase hybridization capture reagent; wherein the pre-library construction reagent comprises a repair reagent, a joint, a connection reagent, an amplification reagent and purified magnetic beads; the target area liquid phase hybridization capture reagent comprises a hybridization reagent, a cleaning reagent, an amplification reagent, a purification magnetic bead, a target gene probe and a CNV / LOH probe. The invention provides a rapid, accurate and low-cost construction method of a library containing a targeting gene probe and a CNV / LOH probe and application of the library, through one-time library construction and sequencing, the advantages of a high-throughput targeting sequencing technology and a CNV-Seq technology are integrated; multi-gene point mutation, insertion and deletion, gene copy number variation, large-fragment copy number variation and heterozygosity deletion can be detected at the same time.

The invention discloses a fusion protein of Bst DNA polymerase and ferritin as well as a mutant and application of the fusion protein. The invention firstly provides a Bst DNA polymerase fusion protein obtained by connecting a C end of a monomer ferritin subunit with an N end of a wild type Bst DNA polymerase through a connecting peptide, and large fragments of the wild type Bst DNA polymerase are repeatedly and orderly displayed on the surface of intense pyrococcus ferritin with strong heat resistance, so that the enzyme activity and the heat stability of the fusion protein are improved; the fusion protein is further subjected to single-site and double-site mutation, compared with a wild type Bst DNA polymerase and the fusion protein, the enzymatic activity, specific activity and thermal stability of the obtained mutant are remarkably improved or improved, LAMP specific amplification reaction can still be carried out at the highest temperature of 85 DEG C, and the application prospect is wide. The reaction preciseness is improved, the use cost of the enzyme is reduced, and the method can be applied to a loop-mediated isothermal amplification technology in a more complex scene.

The invention belongs to the field of biological pharmacy and biological conversion, and particularly relates to a lipase mutant and application thereof. The lipase CALB mutant disclosed by the invention is obtained by carrying out single-point mutation or combined mutation on the 40th site, the 134 site, the 154 site, the 189th site, the 278th site and the 281 site of an amino acid sequence as shown in SEQ ID NO.1. Compared with a wild type, the mutant has the advantage that the stereoselectivity is greatly improved when the mutant is used for catalyzing racemization 3-cyclohexene-1-methyl formate to produce (S)-3-cyclohexene-1-formic acid. Compared with a traditional chemical method for preparing (S)-3-cyclohexene-1-formic acid, the lipase CALB mutant provided by the invention is high in stereoselectivity, mild in reaction condition, environment-friendly, low in equipment requirement, capable of greatly reducing the production cost and wide in application prospect in industrial application.

The present disclosure relates in some aspects to methods for analyzing target nucleic acids and their spatial locations in a biological sample. In some aspects, the presence / absence, amount, and / or identity of variant sequences (e.g., single nucleotide variations such as SNPs or point mutations) in a plurality of target nucleic acids in a cell or tissue sample are analyzed in situ in the sample. Also provided are compositions and kits for use in accordance with the methods.

The invention belongs to the technical field of microbial genetic engineering, and particularly relates to an alpha-2, 3-sialyltransferase mutant and application thereof. The a-2, 3-sialyltransferase mutants V175N, P198A, G173D, D174Q, F196K and A315H are obtained by performing site-specific mutagenesis on six amino acids in an a-2, 3-sialyltransferase amino acid sequence coded by a gene derived from Campylobacter jejuni (OH4384), the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3'-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the P198A, the G173D, the D174Q, the F196K and the A315H, the optimal recombinant microbial strain 3 '-SL-09 (V175N / P198A / D174Q) is obtained through combination of multiple mutation sites, the yield can reach 5.91 g / L, the bottleneck problem of low catalytic efficiency of sialyltransferase is effectively solved, and an enzyme element with excellent performance is provided for high-efficiency and low-cost biological manufacturing of 3'-SL.

The invention relates to the technical field of biological medicines, in particular to a rabies virus G protein mutant as well as a preparation method and application thereof. The rabies virus G protein mutant is obtained by carrying out point mutation on an extracellular domain of G protein, the mutant realizes soluble expression of the extracellular domain of the G protein, can induce generation of a high-titer neutralizing antibody, and has more excellent cellular immunity and antibody immune response compared with commercial human rabies vaccines and canine rabies vaccines; the inoculation frequency is expected to be reduced, the immune procedure is shortened, and the immune dosage is reduced.

The invention discloses a 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant and an application of the 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant. Compared with a wild enzyme amino acid sequence as shown in SEQ ID NO.1, the amino acid sequence of the 3 '-adenosine-5'-phosphoryl sulfate synthetase mutant has one or two mutations in the 101 site, the 207 site and the 560 site; preferably, phenylalanine at the 101 site is mutated into tryptophan; cysteine at the 207th site is mutated into glycine; phenylalanine at the 560th site is mutated into tryptophan. The invention also provides a synthesis method and application of the 3 '-adenosine-5'-phosphoryl sulfuric acid. The APS intermediate product inhibition effect of hPAPSS1 is relieved through a point mutation technology, the substrate affinity of hPAPSS1 to ATP is improved, and a mutant enzyme with a high PAPS conversion rate is obtained; and the bifunctional enzyme hPAPSS1 is synthesized by heterologous expression of PAPS in escherichia coli, so that the acquisition of the enzyme is simplified, and the synthesis efficiency of PAPS is improved.

The present invention provides an ATP phosphoribosyltransferase mutant and its application in histidine production. The mutant is obtained by performing point mutations at positions 84 and / or 205 on the amino acid sequence of the wild-type ATP phosphoribosyltransferase derived from Acinetobacter baumannii. The mutant, the nucleic acid molecule encoding the mutant, the expression cassette containing the nucleic acid molecule, the recombinant vector or the recombinant microorganism are used for the production of L-histidine, and the yield of L-histidine is significantly increased, laying a good foundation for the large-scale industrial production of L-histidine.

The invention discloses an L-aspartic acid transaminase mutant and application thereof. The L-aspartic acid transaminase mutant is obtained by performing single mutation on the 104th amino acid of the amino acid sequence of L-aspartic acid transaminase. The L-aspartic acid transaminase mutant is used for synthesizing an L-phenylglycine derivative. The L-aspartic acid transaminase mutant is from escherichia coli, homologous sequence analysis and molecular docking simulation are carried out, site-specific mutagenesis verification is combined, and single-point mutation is carried out on the 104 amino acid to obtain the T104S mutant. The L-aspartic acid transaminase mutant disclosed by the invention can be used for efficiently catalyzing to generate an L-phenylglycine derivative, and compared with a wild type, the specific activity of the T104S mutant to o-chlorophenoxyacetic acid is 3.2 times that of the wild type.

The present invention provides a 4-vinylguaiacol oxygenase mutant for synthesizing vanillin, and an engineered bacterium thereof. The 4-vinylguaiacol oxygenase mutant is an enzyme having the sequence as shown in SEQ ID NO. 1, which exhibits a double-site mutation of D27P / T216M, D27P / M351F, D27P / Y156D, M351F / Y156D, T216M / Y156D or T216M / M351F, or a single-site mutation of T216M, T216L, S280M, G307P or M351F, and can be used for catalyzing 4-vinylguaiacol to generate vanillin.

The invention belongs to the technical field of biological pharmacy, and particularly relates to influenza virus-like particles for chimeric expression of new coronavirus RBD protein as well as a preparation method and application of the influenza virus-like particles. The virus-like particle is prepared by embedding fusion protein on the surface of influenza virus M1, and the fusion protein comprises an HA2 segment of HA protein of influenza virus, an extracellular functional region of M2e matrix protein, a conserved region short peptide of nucleoprotein, and RBD tandem protein with mutated five sites of 417, 452, 478, 484 and 501 of new coronavirus; the virus-like particles can be used for preventing specific influenza and new crowns; the preparation method of the virus-like particles is simple and low in cost, the virus-like particles are good in immunogenicity and cross protectiveness, the preparation requirements of large-scale influenza vaccines can be met, the biological safety is high, and the immunity of an organism to various influenza viruses and new coronal viruses can be stimulated.

Disclosed is a Taq DNA polymerase mutant. Compared to a wild-type Taq DNA polymerase, the Taq DNA polymerase mutant has a mutation at one or more of amino acid positions 116, 439, and 468, wherein the amino acid sequence of the wild-type Taq DNA polymerase is set forth in SEQ ID NO: 1. Compared to the wild-type Taq DNA polymerase, the Taq DNA polymerase mutant of the present invention has higher enzyme activity than the wild-type enzyme; both single-site mutants and multi-site mutants show improved tolerance to corn leaf supernatant, mouse serum, and / or heparin sodium, and thus can be used for direct rapid amplification of samples.

The invention belongs to the technical field of bioengineering, and particularly relates to a polyphosphate kinase mutant and application thereof in synthesis of beta-nicotinamide mononucleotide, and the polyphosphate kinase mutant is obtained by single-point or multi-point mutation of 99th, 186th, 190th and 204th amino acids of polyphosphatase with an amino acid sequence shown as SEQ ID NO.1. The invention also relates to a preparation method of the polyphosphate kinase mutant, and the application of the polyphosphate kinase mutant in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide. Polyphosphokinase derived from Lampropedia Hyalina DSM 16112 is subjected to molecular modification to obtain multiple mutants, the enzyme activity of the mutants is improved by 1.5-14 times compared with that of wild type polyphosphokinase, the preference of the mutants to AMP is improved by 1.08-4.88 times compared with that of the wild type polyphosphokinase, and an ATP regeneration system constructed by the mutants can remarkably reduce the use amount of enzyme and reduce the fermentation capacity and cost; the reaction time can be greatly shortened, the influence of AMP on the enzyme activity is reduced, the requirements of large-scale industrial production of NMN prepared by adopting a biological enzyme method can be met, and the method has a wide application prospect.

The invention discloses a dihydrodaidzein reductase mutant and application of the dihydrodaidzein reductase mutant in synthesis of (3S, 4R)-tetrahydrodaidzein, and belongs to the technical field of biology. According to the mutant, wild-type dihydrodaidzein reductase DHDR is taken as a parent, single-point mutation or combined mutation is carried out, and a DHDR mutant is obtained; the parent site of the single point mutation is one of the 120th site, the 122nd site, the 170th site, the 178th site, the 214th site, the 219th site, the 220th site or the 220th site; the combined mutation adopts two modes: one mode is that a single-point mutation DHDR mutant is taken as a parent, mutation is carried out, and a combined mutation mutant I is obtained; and 2, taking the DHDR combined mutation mutant I as a parent, and performing mutation to obtain a combined mutation mutant II. The DHDR mutant disclosed by the invention is used for synthesizing (3S, 4R)-tetrahydrodaidzein by reducing dihydrodaidzein, and asymmetric reduction with high activity and high stereoselectivity can be realized.

The invention discloses a fungal virus mutant as well as a construction method and application thereof, and belongs to the technical field of fungal virus modification. The fungal virus mutant is obtained by point mutation of an initiation codon ATG for coding a protein p18 in an infectious clone pSK-ABC into ACG, a coding gene of the protein p18 is located in an open reading frame of a component C at the 3533rd-5463rd sites of a complete sequence of the infectious clone pSK-ABC, and a nucleotide sequence of the infectious clone of the mutant is shown as SEQ ID NO: 1. The phenotype of the mutant virus infected strain is observed to find that the Mp18 mutant virus can reduce the growth speed of host fungi, and causes the characteristics of abnormal host colonial morphology, conidium yield and pathogenicity reduction and the like; besides, when the attenuated strain induced by the Mp18 mutant and the virulent strain are co-inoculated, scab extension on wheat leaves can be effectively inhibited, so that the effect of preventing and controlling the fusarium graminearum virulent strain is achieved.

The invention discloses a beta-galactosidase mutant with improved thermal stability and application of the beta-galactosidase mutant. The amino acid sequence of wild type beta-galactosidase Bgal1-3 is used as a parent, and the beta-galactosidase mutant with improved thermal stability is obtained by performing single-point mutation and combined mutation on amino acid at a specific site of the amino acid sequence of the wild type beta-galactosidase Bgal1-3. The thermal stability is improved, the lactase activity of part of mutants is also improved, and lactose in milk can be rapidly hydrolyzed under the high-temperature condition. The beta-galactosidase mutant disclosed by the invention can be used for degrading lactose and producing low / no-lactose dairy products, and has a promoting effect on the development of the low / no-lactose dairy product industry.

The invention belongs to the technical field of genetic engineering, and particularly relates to a method for creating a corn dwarfing material and application of the corn dwarfing material. The invention discloses a method for creating a corn dwarfing material, which specifically comprises the following steps: carrying out specific key site editing on a target gene ZmGA20ox3 and / or ZmGA20ox5 in corn by using a genetic engineering means, and carrying out specific amino acid site mutation on a protein coded by the target gene ZmGA20ox3 and / or ZmGA20ox5 subjected to specific key site editing, and further cultivating and screening to obtain the corn dwarfing material. The method provided by the invention can be used for cultivating transgenic corn plants with different plant heights and other agronomic traits, and meanwhile, a new breeding technical scheme is provided for creating dwarf corn, reducing the height of a corn ear, reducing the included angle of corn plant leaves and increasing the corn yield; crops can be more densely planted in agriculture, so that the yield of the crops in unit area is improved, and the method has important breeding significance.

The invention provides p-hydroxymandelic acid synthetase, a gene, a mutant of the p-hydroxymandelic acid synthetase and application of the p-hydroxymandelic acid synthetase in asymmetric synthesis of (S)-mandelic acid. The p-hydroxymandelic acid synthetase disclosed by the invention is derived from actinomycetes Actinokineospora auranticola, the amino acid sequence of the p-hydroxymandelic acid synthetase is as shown in SEQ ID NO.1, and a mutant of the p-hydroxymandelic acid synthetase is obtained by performing single-point mutation or multi-point combined mutation on glutamic acid at the 187th site, isoleucine at the 189th site and threonine at the 211th site of the amino acid sequence as shown in SEQ ID NO.1. The p-hydroxymandelic acid synthetase and the mutant thereof can convert phenylpyruvic acid into (S)-mandelic acid with high optical purity, have the advantages of mild reaction conditions, simplicity and convenience in operation, safety, environment friendliness and the like, and have a very good industrial application prospect.