CN105367634A - Bt protein Cry1Ie5 and coding gene and application thereof - Google Patents

Abstract

The invention provides a Bt protein Cry1Ie5 and a coding gene thereof. The protein is of an amino acid sequence shown in the SEQIDNo.2 or of an amino acid sequence obtained by replacing, missing and/or adding one or more amino acids of the amino acid sequence shown in the SEQIDNo.2, wherein the amino acid sequence is the same as the amino acid sequence shown in the SEQIDNO.2 in activity. The protein can be used for preparing a Bt pesticide, the gene for coding the protein can convert cotton, corns, rice, vegetables and other crops, and the corresponding insect resistant activity is achieved, so that the pesticide using amount is lowered, environment pollution is reduced, and the important economic value and application prospects are achieved.

Description

A kind of Bt PROTEIN C ry1Ie5, its encoding gene and application

Technical field

The present invention relates to biological technical field, be specifically related to a kind of Bt albumen and encoding gene thereof and application.

Background technology

In human being's production process, insect pest causes agriculture production to lose and affects the important factor of human health.According to FAO statistics, the financial loss that whole world agriculture production causes because of insect pest is every year up to 14%, and disease loss reaches 12%, and crop smothering loss reaches 11%.The amount of loss, up to 1,260 hundred million dollars, is equivalent to the half of the Chinese agriculture gross output value, more than 4 times of Britain.In order to reduce these losses, for many years, chemical prevention means are generally adopted to prevent and treat to crop pests and mosquito, but due to chemical pesticide long-term, use in a large number, cause the pollution to environment, agricultural byproducts Pesticide Residues increases, and brings harm to the existence of the mankind and health.In addition, chemical pesticide, while kill pests, has has also killed and wounded natural enemy and other useful thing, has destroyed the eubiosis.Compared with chemical prevention, biological control has safe, effective, lasting feature.And avoid the series of problems that chemical prevention brings.Therefore, biological prevention has become the focus that people study.In biotic pesticide, bacillus thuringiensis is the quasi-microorganism sterilant that purposes is the widest in the world, output is maximum at present.

Bacillus thuringiensis ( bacillusthuringiensis, be called for short Bt) and be a kind of gram positive bacterium, its distribution is very extensive, the parasporal crystal be made up of protein with insecticidal activity can be formed while sporulation, have another name called insecticidal crystal protein (Insectididalcrystalproteins, be called for short ICPs), ICPs be by crygenes encoding, there is strong toxicity to sensitive insect, and to higher animal and people's nontoxicity.At present in the control of agricultural pests, injurious forest-insect and sanitary insect pest, Bt has become the strong substitute of chemical synthetic pesticide, Bt or the important gene source of transgenic pest-resistant engineered plant.

From Schnepf in 1981 cloned from strain HD-1 first can express the gene of insecticidal activity since, people are the separating clone gene of 500 Multi-encoding insecticidal crystal proteins, according to the amino acid sequence homology of encoding, they are determined respectively to be different groups, subgroup, class and subclass (CrickmoreN etal.microbiolMolBiolRev, 1998,62:807-813; Http:// www.biols.susx.ac.uk/Home/Neil_Crickmore/Bt/).Generally speaking, cry1, Cry2with cry9effective to lepidoptera pest Deng toxalbumin; What wherein study maximum is cry1with cry9proteinoid, the insecticidal crystal protein molecular weight of their codings is 130-140kD, and many genes have been widely used in the control of the lepidoptera pest of plant at present.Bacillus thuringiensissubsp.israelensis ( b.thuringiensissubsp. israelensis, being called for short Bti) and the toxin protein that produces has fine insecticidal activity to mosquito, is widely used in the control of mosquito.Meanwhile, cytalbumen has cytolytic, to some cryalbumen has synergism and delays the resistance of insect.

Utilization of pesticides based on Bt insecticidal crystal protein has the history of more than 50 year, the resistance of insect to Bt never detected at first, but, mid-term 80 year last century starts, resistance problem is constantly confirmed (McGaughey in laboratory and field test, W.H.1985.Science.229:193-195), the application that reason mainly continues to use single variety and Asia to cause Bt and the Bt transgenic anti-insect plants of dosage causes insect population to be subject to the selective pressure of sterilant for a long time.1985, McGaughey report warehouse grain pest Indian meal moth ( plodiainterpunctella) at Dipel (Btsubsp. kurstaikthe commercial preparation of HD-1) selective pressure under, after breeding for 15 generations, resistance increases by 97 times; Under high dosage selective pressure, resistance can increase by 250 times.Nineteen ninety, confirm first in Hawaii the small cabbage moth of large Tanaka to Bt sterilant create obvious resistance (Tabashnik, B.E., etal.1994.Proc.Natl.Acad.Sci.USA.91:4120-4124); since the nineties in last century; on the ground such as Shenzhen and Guangzhou, Shanghai that China's application Bt pesticide time is longer; find that Bt sterilant obviously declines to small cabbage moth prevention effect; mean that resistance is formed (Feng Xia .1996. insect journal, 39 (3): 238-244; Hofte, H., 1988.Appl.Environ.Microbiol.54:2010-2017).Current discovery has at least tens kinds of insects to create resistance to Bt and insecticidal crystal protein thereof in laboratory and field, arrive with selective pressure mathematical model prediction, under the condition of Bt transgenic anti-insect plants selective pressure, insect will produce resistance (Schnepf, E., etal.1998.Mol.Biol.Rev.65 (3): 775-806).In addition, there are some researches prove that Bti not yet finds resistance problem in the use in land for growing field crops, but mosquito is constantly confirmed in the lab to its resistance problem, also (GeorghiouGP may be there is large Tanaka in this situation, 1997.AppliedandEnvironmentalMicrobiology, 63:1095-1101.).

The loss caused for avoiding resistant insects, finding new high virulence Bt genetic resources is the effective way addressed this problem, and this has very important meaning to the biological control of China.

Summary of the invention

First object of the present invention is to provide a kind of new Bt virulence protein resource for above-mentioned deficiency.

Second object of the present invention is the gene providing encoding said proteins.

3rd object of the present invention is the application providing above-mentioned albumen and gene.

The present invention is separated the bacillus thuringiensis new strains BN23-5 obtained from the Soils In The Region of Chengdu, Sichuan Province, this bacterial strain (was called for short CGMCC on 07 14th, 2014 at China Committee for Culture Collection of Microorganisms's common micro-organisms center, address: No. 3, Yard 1, BeiChen xi Road, Chaoyang District, Beijing City, Institute of Microorganism, Academia Sinica, postcode 100101) preservation, Classification And Nomenclature be bacillus thuringiensis ( bacillusthuringiensis), preserving number is CGMCCNo.9448.

By showing the virulence test of BN23-5, BN23-5 has high virulence to lepidoptera pest etc.According to cry1Igenoid conserved sequence designs a pair special primer, and increase its genomic dna, and result shows to exist in this bacterial strain cry1Igenoid, further its full-length gene primer of design, clone obtains cry1Ia-likegene, its nucleotide sequence is as shown in sequence table SEQ IDNo.1, and total length is 2160bp, and analysis shows, GC content is 36.81%, the albumen of 720 amino acid compositions of encoding.After measured, its aminoacid sequence is as shown in SEQIDNo.2.Adopt in softberry website bacterialsigma7.0promoter program to carry out prediction to complete sequence to show, contain the sequence in RNA polymerase activation site in upstream, gene coding region, by its called after Cry1Ie5.Cry1Ie5the amino acid composition of albumen is as table 1.

Should be appreciated that those skilled in the art can according to albumen disclosed by the invention cry1Ie5'saminoacid sequence (SEQIDNo.2), under the prerequisite not affecting its activity, replaces, lacks and/or increases one or several amino acid, obtains the mutant nucleotide sequence of described albumen.Such as at nonactive section, the Lys of the 44th is replaced with Arg, or the Leu of the 713rd is replaced with Ile, and do not affect its activity.Therefore, Bt albumen of the present invention cry1Ie5also comprise aminoacid sequence shown in SEQIDNo.2 and be substituted, replace and/or increase one or several amino acid, have and Bt albumen cry1Ie5with isoreactivity by cry1Ie5the derivative protein obtained.

Gene of the present invention comprises encoding said proteins cry1Ie5'snucleotide sequence.

The invention provides the above-mentioned Bt albumen of coding cry1Ie5gene, its nucleotides sequence is classified as:

(1) nucleotide sequence shown in sequence table SEQ IDNO.1, or

(2) nucleotide sequence shown in SEQIDNo.1 is substituted, lacks and/or increases one or several Nucleotide.

In addition, should be understood that the preferences of degeneracy and the different plant species codon considering codon, the codon that those skilled in the art can use applicable specific species to express as required.

Gene of the present invention can be cloned or be separated from Bt bacterial strain BN23-5 with protein and be obtained, or is obtained by the method for DNA or peptide symthesis.

Gene of the present invention can be operably connected with expression vector, obtain the recombinant expression vector can expressing albumen of the present invention, and then by transgenic methods such as such as agrobacterium-mediated transformation, particle bombardment, pollen tube passage methods, described expression vector can be imported host, obtain turning cry1Ie5the transformant of gene, the such as plant such as farm crop or fruit tree, make it possess anti-insect activity.

In one embodiment of the invention, Bt albumen cry1Ie5the acquisition of recombinant expression vector is by inciting somebody to action cry1Ie5gene is inserted into the upper structure of expression vector pET-28a (+) and obtains recombinant expression vector pET-1I.

In addition, by fermentation bacterial strain BN23-5 of the present invention, can also be contained cry1Ie5the fermented liquid of albumen, is prepared into sterilant, for the control of crop pests.Those skilled in the art can also by said gene transform bacteria or fungi, by large scale fermentation production Bt albumen of the present invention.

Present invention also offers Bt albumen cry1Ie5improving the application in plant resistance to insect.

The invention provides Bt albumen cry1Ie5cultivating the application in transgenic plant.

Those skilled in the art can also according to disclosed by the invention cry1Ie5gene, by farm crop such as its converting cotton, corn, paddy rice, vegetables, makes it possess corresponding anti-insect activity.Such as: the degeneracy utilizing codon, will cry1Ie5gene design has the gene order of paddy rice preferred codons, then by synthesis cry1Ie5gene order is connected with carrier pCAMBIA1300, is transferred in rice genome by agriculture bacillus mediated, thus obtains the Transgenic Rice with anti-insect activity.

The invention provides cry1Ie5albumen is a kind of Bt albumen, has good insecticidal activity, uses it for preparation transgenic plant, can specific killing insect, and reduces the usage quantity of agricultural chemicals, reduces costs, reduces environmental pollution.In compliance test result process of the test of the present invention, do not find that insect produces the situation of resistance to this albumen yet.Therefore, Bt albumen of the present invention cry1Ie5there is important economic worth and application prospect, be applicable to large-scale application in the insect-resistance improving plant.

Accompanying drawing explanation

What Fig. 1 showed is the gel electrophoresis figure of cloning the Cry1Ie5 full-length gene obtained, wherein M, DNAmarker; 1, Cry1Ie5 gene;

Fig. 2 display be that the enzyme of recombinant plasmid pET-1I cuts qualification collection of illustrative plates, the wherein BamHI+HindIII double digestion product of 1, recombinant plasmid pET-1I; 2, carrier pET-28a; 3, recombinant plasmid pET-1I; 4, the DNA of insertion; M, DNAmarker;

What Fig. 3 showed is that the SDS-PAGE that Cry1Ie5 gene is expressed in E.coliBL21 (DE3) detects figure; Wherein 1, the E.coliBL21 (DE3) containing carrier pET-28a through IPTG induction after cellular lysate liquid supernatant liquor (negative control); 2, the E.coliBL21 (DE3) containing carrier pET-28a) cellular lysate liquid precipitate (negative control) after IPTG induction; 3, the E.coliBL21 (DE3) containing recombinant plasmid pET-1I through IPTG induction after cellular lysate liquid supernatant liquor; 4, the E.coliBL21 (DE3) containing recombinant plasmid pET-1I through IPTG induction after cellular lysate liquid precipitate; M, albumen marker.

Embodiment

Following examples further illustrate content of the present invention, but should not be construed as limitation of the present invention.Without departing from the spirit and substance of the case in the present invention, the amendment do the inventive method, step or condition or replacement, all belong to scope of the present invention.

If do not specialize, biochemical reagents used in embodiment are commercial reagent, the conventional means that technique means used in embodiment is well known to those skilled in the art.

Embodiment 1 cry1Ie5the clone of gene

The present invention be separated from the Soils In The Region of Chengdu, Sichuan Province obtain bacillus thuringiensis ( bacillusthuringiensis) new strains BN23-5, this bacterial strain on 07 14th, 2014 in (address: No. 3, Yard 1, BeiChen xi Road, Chaoyang District, Beijing City, China Committee for Culture Collection of Microorganisms's common micro-organisms center, Institute of Microorganism, Academia Sinica, postcode 100101) preservation, Classification And Nomenclature be bacillus thuringiensis ( bacillusthuringiensis), preserving number is CGMCCNo.9448.

This example is cloned by the following method and is obtained cry1Ie5the full length sequence of gene.

Genomic DNA purification kit (purchased from match Parkson company) is adopted to extract the STb gene of bacterial strain BN23-5 as amplification cry1Ie5the template of gene, design primer sequence is as follows:

P1（SEQIDNo.3）：5’-ATGAAACTAAAGAATCAAGATAAG-3;

P2（SEQIDNo.4）：5’-CTACATGTCACGCTCAATAT-3’

25 μ lPCR reaction systems:

10×buffer2.5μl

MgCl ₂(25mM)1.5μl

Taq enzyme 0.2 μ l

dNTPs(2.5mM)2μl

Primer P11 μ l

Primer P21 μ l

Template 5 μ l

Distilled water 11.8 μ l

Thermal cycle reaction: 94 DEG C of denaturation 5min; 94 DEG C of sex change 50s, 54 DEG C of 50s, 72 DEG C extend 2min, 30 circulations; 72 DEG C extend 10min; 4 DEG C of stopped reaction.Amplified reaction product is electrophoresis on 1% sepharose, puts in gel imaging system and observes pcr amplification result.As shown in Figure 1, obtain by amplification the sequence being about 2160bp, this sequence checked order, its nucleotide sequence is as shown in SEQIDNo.1, consistent with aim sequence for result.

Embodiment 2 cry1Ie5the acquisition of albumen

According to cry1Ie5gene open reading frame two terminal sequence, designs and synthesizes a pair special primer 1ITF(SEQIDNo.5): 5'-GCC gGATCCaTGAAACTAAAGAATCAAGATAAG-3', 1ITR(SEQIDNo.6): 5'-CCCA aAGCTTcTACATGTCACGCTCAATAT-3', 5 ' end primer underscore number of base is respectively bamHIwith hindIIIrestriction enzyme site.With BN23-5 STb gene for template increases, digestion products carries out the carrier pET-28a (+) after double digestion connect with same, transforms e.colidH5 α competent cell, extracts its plasmid enzyme restriction electrophoresis and demonstrates and insert segment size and meet (Fig. 2) after expection object fragment, then proceed to recipient bacterium e.coli.BL21 (DE3) (buying in Beijing Quanshijin Biotechnology Co., Ltd).By recombinant plasmid called after pET-1I, containing the recon called after of recombinant plasmid e.coli.BL21 (2L).By positive transformant in LB substratum, in 200r/min, 37 DEG C of incubated overnight, again nutrient solution is transferred in the 1L triangular flask containing 400mLLB nutrient solution according to the ratio of 1:100,200r/min, 37 DEG C of cultivations, when the OD=600 value of nutrient solution reaches 0.6-0.8, add 0.6mmol/LIPTG and carry out abduction delivering 12h, centrifugation medium collects thalline, abandon supernatant, add 30mL10mmol/LTris-HCl (pH8.0) ultrasonic disruption, with SDS-PAGE, expressing protein is detected.

SDS-PAGE analytical table Benq because of the precipitation of expression product after thalline ultrasonication and supernatant liquor in (Fig. 3), cry1Ie5molecular weight is about about 81.3kDa, conforms to the molecular weight of albumen of prediction.

Embodiment 3 cry1Ie5albumen insecticidal activity assay

Embodiment 2 is obtained cry1Ie5albumen carries out insecticidal activity assay to small cabbage moth and Pyrausta nubilalis (Hubern)..The raw of small cabbage moth is surveyed: will cry1Ie5albumen is mixed with the different concentration gradient of 4,2,1,0.5,0.25,0.01ug/mL etc. 6; Select old tender moderate Cabbage leaf to clean, dry; Irradiate 15min under ultraviolet lamp, be cut into 2 × 2cm ²size, divides and is placed in different concns bacterium liquid, soaks 5min; Take out and drain unnecessary liquid, be placed in the culture dish of sterilization and dry, e.coli.bL21 (DE3) is as negative control, and clear water is blank, and each culture dish puts 4 blades; Healthy 2-3 small cabbage moth in age 20 is put in choosing; Often process repetition 3 times, put indoor, in 3d " Invest, Then Investigate " dead larvae situation.The raw of Pyrausta nubilalis (Hubern). is surveyed: will cry1Ie5albumen is mixed with the different concentration gradient of 200,100,50,25,12.5,0.1ug/mL etc. 6, is added by albumen in the feed of raising Pyrausta nubilalis (Hubern). and mixes, e.coli.bL21 (DE3) is as negative control, and clear water is blank, then often processes input 20 2-3 Pyrausta nubilalis (Hubern).s in age, often processes 3 times and repeats, statistics after 7d.Use SPSS10.0 computed in software lC ₅₀ .

Result shows (table 2): the insecticidal activity that expression product is high to small cabbage moth tool, lC ₅₀ it is for 0.43ug/mL, also very high to Pyrausta nubilalis (Hubern). insecticidal activity, lC ₅₀ for 48.39ug/mL; Raw result of surveying shows, e.coli.bL21 (DE3) and blank do not have an insecticidal activity to small cabbage moth and Pyrausta nubilalis (Hubern)..

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Although above the present invention is described in detail with a general description of the specific embodiments, on basis of the present invention, can make some modifications or improvements it, this will be apparent to those skilled in the art.Therefore, these modifications or improvements without departing from theon the basis of the spirit of the present invention, all belong to the scope of protection of present invention.

Claims (10)

1. a Bt albumen cry1Ie5, it is characterized in that, its aminoacid sequence is:

1) aminoacid sequence shown in SEQIDNo.2; Or

2) aminoacid sequence shown in SEQIDNo.2 is substituted, lacks and/or increases one or more amino acid and has the aminoacid sequence of same isoreactivity.

2. the gene of albumen described in coding claim 1.

3. gene as claimed in claim 2, it is characterized in that, its nucleotides sequence is classified as:

As shown in SEQ ID No .1; Or

One or several Nucleotide is substituted, the nucleotide sequence obtained by nucleotide sequence shown in SEQIDNo.1.

4. the recombinant expression vector containing gene described in Claims 2 or 3.

5. the host cell transformed by expression vector described in claim 4.

6. host cell as claimed in claim 5, it is plant host cell.

7. the sterilant containing albumen described in claim 1.

8. albumen according to claim 1 or its encoding gene are preparing the application in sterilant.

9. albumen according to claim 1 or its encoding gene are cultivating the application in transgenic plant.

10. albumen according to claim 1 or its encoding gene are improving the application in plant resistance to insect.