Summary of the invention
The purpose of this invention is to provide a kind of soybean SCN rna helicase enzyme CGH-1 and encoding sox and application.
Protein provided by the invention available from soybean SCN (Heterodera glycines, Soybean cyst nematode), is (a) or (b) as follows:
(a) protein of forming by the aminoacid sequence shown in the sequence in the sequence table 1;
(b) with the aminoacid sequence of sequence 1 through the replacement of one or several amino-acid residue and/or disappearance and/or interpolation and grow relevant by sequence 1 deutero-protein with the soybean SCN.
In order to make the protein in (a) be convenient to purifying, proteinic N-terminal or C-terminal that can the aminoacid sequence shown in the sequence 1 is formed in by sequence table connect label as shown in table 1.
The sequence of table 1 label
Label |
Residue |
Sequence |
Poly-Arg |
5-6 (being generally 5) |
RRRRR |
Poly-His |
2-10 (being generally 6) |
HHHHHH |
FLAG |
8 |
DYKDDDDK |
Strep-tag?II |
8 |
WSHPQFEK |
c-myc |
10 |
EQKLISEEDL |
Above-mentioned (b) but in the protein synthetic, also can synthesize its encoding sox earlier, carry out biology again and express and to obtain.Proteinic encoding sox in above-mentioned (b) can be through the codon with one or several amino-acid residue of disappearance in the dna sequence dna shown in the sequence in the sequence table 2; And/or carry out the missense mutation of one or several base pair, and/or obtain at the encoding sequence that its 5 ' end and/or 3 ' end connects the label shown in the table 1.
The gene of encoding said proteins also belongs to protection scope of the present invention.
Said gene can be following 1) to 4) in arbitrary described dna molecular:
1) sequence 2 of sequence table is from the dna molecular shown in 5 ' terminal the 499th to 1839 Nucleotide;
2) dna molecular shown in the sequence 2 in the sequence table;
3) under stringent condition with 1) or 2) the dna sequence dna hybridization that limits and the dna molecular of coding soybean SCN development associated protein;
4) with 1) or 2) dna sequence dna that limits has 90% above homology and the dna molecular of the soybean SCN development associated protein of encoding.
Above-mentioned stringent condition can be 0.1 * SSPE (or 0.1 * SSC), in the solution of 0.1%SDS, hybridization and wash film under 65 ℃ of conditions.
The recombinant expression vector, expression cassette, transgenic cell line or the reorganization bacterium that contain said gene all belong to protection scope of the present invention.
The present invention also protects the recombinant plasmid (interference plasmid) that contains double chain DNA fragment A and double chain DNA fragment B; Said double chain DNA fragment B and said double chain DNA fragment A are reverse complementary sequence; Said double chain DNA fragment A like the sequence 2 of sequence 2 from shown in 5 ' terminal 523 to 1090 Nucleotide.Said recombinant plasmid also can comprise 3 ' end untranslated zone of foreign gene, promptly comprises the dna fragmentation of polyadenylic acid signal and any other participation mRNA processing or genetic expression.Said polyadenylic acid signal can guide polyadenylic acid to join 3 ' end of mRNA precursor.When making up said recombinant plasmid, before its transcription initiation Nucleotide, can add any enhancement type promotor or constitutive promoter, they can use separately or be used in combination with other promotor; When making up said recombinant plasmid; Also can use enhanser, comprise translational enhancer or transcriptional enhancer, these enhanser zones can be ATG initiator codon or neighboring region initiator codon etc.; But must be identical with the reading frame of encoding sequence, to guarantee the correct translation of whole sequence.The source of said translation wave and initiator codon is widely, can be natural, also can be synthetic.Translation initiation region can be from transcription initiation zone or structure gene.For the ease of transgenic plant being identified and screening; Can process used recombinant plasmid, can produce enzyme or the gene of luminophor, antibiotic marker thing or the anti-chemical reagent marker gene etc. of colour-change with resistance as adding the coding that in plant, to express.Also can not add any selected marker, directly with adverse circumstance screening transformed plant.Said recombinant plasmid can be different MCSs at carrier pZH01 and inserts the recombinant plasmid that said double chain DNA fragment A and said dna fragmentation B obtain respectively.Said recombinant plasmid specifically can be and is inserting the recombinant plasmid that the said double chain DNA fragment B of insertion obtains between said double chain DNA fragment A, Kpn I and the Sac I restriction enzyme site between the Xba of skeleton carrier pZH01 I and the Sal I restriction enzyme site.
The present invention also protects a kind of method of cultivating transgenic plant, is said recombinant plasmid is imported in the purpose plant, obtains the transgenic plant that soybean SCN resistance is higher than said purpose plant.Conventional biological method transformed plant cells or tissues such as said recombinant plasmid can Ti-plasmids, Ri plasmid, plant viral vector, directly DNA conversion, microinjection, electricity be led through using, agriculture bacillus mediated (like Agrobacterium rhizogenes K599), particle gun, and the plant transformed tissue cultivating become plant.Said purpose plant both can be that monocotyledons also can be a dicotyledons.Said dicotyledons specifically can be soybean, like big pulse family rich No. 1.Said soybean SCN specifically can be No. 4 physiological strains of soybean SCN.
Said albumen, or said gene, or said recombinant expression vector, expression cassette, transgenic cell line or reorganization bacterium, or said recombinant plasmid all can be used for plant breeding, as cultivating Chinese People's Anti-Japanese Military and Political College beans SCN plant.Said purpose plant both can be that monocotyledons also can be a dicotyledons.Said dicotyledons specifically can be soybean, like big pulse family rich No. 1.Said soybean SCN specifically can be No. 4 physiological strains of soybean SCN.
The invention provides soybean SCN rna helicase enzyme CGH-1 and encoding sox thereof; And designed a kind of RNAi expression vector based on this encoding sox, and this RNAi expression vector is imported plant, can be at the dsRNA of gene described in the plant; After sick worm is being taken in transgenic plant; DsRNA gets into enteron aisle, and the siRNA of generation can further get in other the tissue and cell, causes the inactivation of said gene; Make the reproduction of disease worm or grow to produce serious hindrance, thereby suppress infecting and propagating of disease worm.Transgenic plant through method provided by the invention can obtain to have very strong anti-insect activity lay the foundation for further cultivating the new soybean varieties with wide spectrum pest-resistant property.
Embodiment
Following embodiment is convenient to understand better the present invention, but does not limit the present invention.Experimental technique among the following embodiment like no specified otherwise, is ordinary method.Used test materials among the following embodiment like no specified otherwise, is to buy from routine biochemistry reagent shop and obtains.Quantitative test in following examples all is provided with repeated experiments three times, results averaged.
X-Gluc solution (pH 7.0) solvent is a water; Solute and concentration thereof are following: 50mM Na
3PO
4, 10mM Na
2EDTA, 0.1% (volume ratio) Triton X-100,0.1M K
3[Fe (CN)
6], 0.1M K
4[Fe (CN)
6], 0.5g/L X-Gluc and 20% (volume ratio) methyl alcohol.
Soybean SCN (No. 4 physiological strains): the public can obtain with developmental biology institute from Chinese Academy of Sciences's heredity; Reference: Lu Weiguo, Gai Junyi, sample survey and the research of Li Weidong the Yellow River and Huai He River area soybean SCN physiological strain. Scientia Agricultura Sinica, 2006,39 (2): 306-312.
Rich No. 1 of big pulse family: the public can obtain with developmental biology institute from Chinese Academy of Sciences's heredity; Reference: Qi-Yun Zhou, Ai-Guo Tian, Hong-Feng Zou, Zong-Ming Xie; Gang Lei, Jian Huang, Chun-Mei Wang, Hui-Wen Wang; Jin-Song Zhang, and Shou-Yi Chen.Soybean WRKY-type transcription factor genes, GmWRKY13; GmWRKY21, and GmWRKY54, confer differential tolerance to abiotic stresses in transgenic Arabidopsis plants.Plant Biotechnology Journal; 2008,6,486-503.
Soybean susceptible variety Lee: the public can obtain with developmental biology institute from Chinese Academy of Sciences's heredity; Reference: Lu Weiguo, Yuan Daohua, Li Jinying, Li Haichao, Wen Zixiang opens brightness. the variation of the anti-SCN gene of soybean different generations heritability, Henan agricultural sciences, 2010, (2): 24-27.
Carrier pZH01: the public can obtain with developmental biology institute from Chinese Academy of Sciences's heredity; Reference: Junhuang Zou, Shuying Zhang, Weiping Zhang; Gang Li, Zongxiang Chen, Wenxue Zhai; Xianfeng Zhao; Xuebiao Pan, Qi Xie and Lihuang Zhu.The rice HIGH-TILLERING DWARF1 encoding an ortholog of Arabidopsis MAX3 is required for negative regulation of the outgrowth of axillary buds.The Plant Journal, 2006; 48,687-696.
Agrobacterium rhizogenes K599: the public can obtain with developmental biology institute from Chinese Academy of Sciences's heredity; Reference: Attila Kereszt, Dongxue Li, Arief Indrasumunar; Cuc DT Nguyen; Sureeporn Nontachaiyapoom, Mark Kinkema & Peter M Gresshoff.Agrobacterium rhizogenes-mediated transformation of soybean to study root biology, NATURE PROTOCOLS; 2007,2 (4): 948-952.
The discovery of embodiment 1, soybean SCN SCN cgh-1 albumen and encoding sox thereof
One, the selection of soybean SCN SCN cgh-1 albumen and encoding sox thereof
In the DB of NCBI, by in May, 2009, the correlated series of soybean SCN has 108045, comprising 81873 nucleotide sequences, and 26172 est sequences, 183 mRNA and 252 protein sequences.Alkharouf et al handles 24438 est sequences and 231 genome sequences of soybean SCN; And find with the comparison of the gene order of beautiful nematode, have 8334 gene orders similar between the two, and this is wherein; There are 1508 genes that deadly phenotype is arranged in nematode; Have the gene of deadly phenotype to divide into groups according to the sequence similarity degree to these, be divided into 6 groups, wherein the most similar (E-values 0 and 1E-100) gene has 150.The contriver is than right 150 genes and human sibship, and factor such as considered amino acid sequence length selected 13 candidates' lethal gene to clone, and one of them gene is that the present invention finds and the gene of protection.
Two, the discovery of soybean SCN SCN cgh-1 albumen and encoding sox thereof
1, the TRIZOL method is extracted total RNA from the cyst of soybean SCN (No. 4 physiological strains).
2, be cDNA (with the RACE test kit of Clontech: SMART RACE cDNA Amplification Kit, Cat No.634923) with total RNA reverse transcription.
3, the acquisition of gene fragment
(1) design following primer to (target sequence 628bp) through comparison and beautiful nematode cgh-1 homologous soybean SCN est sequence in the DB of NCBI, and according to est sequence:
cgh-1HG?Nhe?I?NS:5’-CCGCTAGCGTTTCTTCTTCGCGTCCGAT-3’;
cgh-1HG?Xho?I?CAS:5’-GGCTCGAGTAGAAACTGAACAAGACGGTC-3’。
(2) cDNA with step 2 is a template, with step 3 designed primer to carrying out pcr amplification.
Pcr amplification system: cDNA 2ul, two each 2ul of primer, MgSO
4Solution 2ul, KOD Plus archaeal dna polymerase 1ul, KOD Plus dna polymerase buffer liquid 5ul, dNTP 5ul, DMSO 1ul, ddH
2O 30ul.
Pcr amplification program (BIO-RAD iCycler): 94 ℃ of 2min, 35 * (94 ℃ of 15s, 57 ℃ of 30s, 68 ℃ of 2min), 68 ℃ of 5min, 12 ℃ of preservations.
The agarose gel electrophoresis result of pcr amplification product sees Fig. 1.
(3) cut glue with OMEGA Gel Extraction Kit (D2500-01) and reclaim band, the agarose gel electrophoresis figure that reclaims band sees Fig. 2.
(4) the PCR fragment that reclaims with the NEB digestion with restriction enzyme.
Enzyme is cut system: glue reclaims product 43.5ul, Nhe I 1ul, Xho I 1ul, Buffer 25ul, BSA 0.5ul.37 ℃ of enzymes are cut and are spent the night, and use OMEGA Gel Extraction Kit (D2500-01) to cut glue then and reclaim.
(5) with NEB digestion with restriction enzyme carrier pPD129.36.
Enzyme is cut system: pPD129.365ul, Hind III 1ul, Xho I 1ul, Buffer 25ul, BSA 0.5ul.37 ℃ of enzymes are cut and are spent the night, and use OMEGA Gel Extraction Kit (D2500-01) to cut glue then and reclaim.
(6) step (4) is connected with NEB T4 Ligase with the fragment that step (5) reclaims.
Linked system: pPD129.36 (enzyme is cut the back) 1ul, gene fragment (enzyme is cut the back) 12ul, T4 Ligase Buffer1.5ul, T4 Ligase 1ul.
(7) connect product heat shock method and transform DH5 α competent cell, be coated with LB flat board (Amp+), 37 ℃ of overnight cultures; After waiting to grow the clone; Choose mono-clonal and identify, obtain positive colony (8) (11), send the order-checking of the English Weihe River prompt base (Shanghai) trade Co., Ltd with the Cloning PCR method.Sequencing result is seen the sequence 3 of sequence table.
4, the segmental acquisition of 5 '-RACE fragment and 3 '-RACE
(1) the PCR Master Mix in the preparation table 2, and gentle vortex mixing avoids producing bubble in the process.
Table 2PCR Master Mix forms
Composition |
Each reaction (ul) |
9 reactions (ul) |
PCR-Grade?Water |
34.5 |
?310.5 |
10X?Advantage?2PCR?Buffer |
5.0 |
?45.0 |
dNTP?Mix(10mM) |
1.0 |
?9.0 |
50X?Advantage?2Polymerase?Mix |
1.0 |
?9.0 |
Total?Volume |
41.5 |
?373.5 |
(2) on the basis of step (1), the reacted constituent of 5 '-RACE PCR and 3 '-RACE PCR is seen table 3 and table 4.
The reactive component of table 35 '-RACE PCR
Composition |
Each reaction (ul) |
5’-RACE-Ready?cDNA |
2.5 |
UPM(10X) |
5 |
GSP1 |
1 |
Master?Mix |
41.5 |
Total?Volume |
50.0 |
The reactive component of table 43 '-RACE PCR
Composition |
Each reaction (ul) |
5’-RACE-Ready?cDNA |
2.5 |
UPM(10X) |
5 |
GSP2 |
1 |
Master?Mix |
41.5 |
Total?Volume |
50.0 |
(3) use BioRad iCycler PCR appearance working procedure (Touchdown PCR), condition is: 5 * (94 ℃ of 30s, 72 ℃ of 3min), 5 * (94 ℃ of 30s, 70 ℃ of 30s, 72 ℃ of 3min), 27 * (94 ℃ of 30s, 68 ℃ of 30s, 72 ℃ of 3min), and 4 ℃ of for ever.Amplification is seen Fig. 3.
(4) behind the agarose gel electrophoresis, cut glue with OMEGA Gel Extraction Kit (D2500-01) and reclaim.
(5) the pEASY-Blunt Simple Cloning Kit with full formula King Company makes up the clone; Obtain positive colony; And send Invitrogen Corp. (INVITROGEN) order-checking, and the sequencing result of 3 '-RACE is seen the sequence 4 of sequence table, the sequencing result of 5 '-RACE is seen the sequence 5 of sequence table.
With the cgh-1 of albumen called after SCN shown in the sequence 1 of sequence table albumen (forming), be a kind of rna helicase enzyme of ATP dependent form by 446 amino-acid residues.With the proteic encoding sox called after of SCN cgh-1 SCN cgh-1 gene; Its cDNA shown in the sequence 2 of sequence table (2128bp), the long 498bp of 5 ' UTP, coding head of district 1341bp (sequence 2 of sequence table is from 5 ' terminal 499-1839 position Nucleotide), the long 289bp of 3 ' UTR.
Embodiment 2, the proteic functional verification of SCN cgh-1
One, the structure of SCN cgh-1RNAi expression vector
1, from the cyst of soybean SCN (No. 4 physiological strains), extract total RNA, and reverse transcription is cDNA.
2, with cDNA be template, the primer of forming with Primer-F and Primer-R carries out pcr amplification to (target sequence is that the sequence 2 of sequence table is from 5 ' terminal 523-1090 position Nucleotide, i.e. SCN cgh-1 gene fragment), obtains pcr amplification product.
Primer-F:5 '-CGC
TCT AGA GAG CTCCGT CCG ATG GAA GAT TG-3 ' (underscore mark Xba I enzyme cuts recognition site and Sac I enzyme is cut recognition site);
Primer-R:5 '-ACG C
GT CGA CGG TAC CGG AAG TCC TGG GAA AGG-3 ' (underscore mark Sal I enzyme cuts recognition site and Kpn I enzyme is cut recognition site);
Pcr amplification system (50 μ l): cDNA 1 μ l, 10 * buffer, 5 μ l, dNTP (10mM) 1 μ l, Primer-F1 μ l, Primer-R 1 μ l, Pfu DNA Polymerase (TaKaRa) 1 μ l, ddH
2O 40 μ l.
Pcr amplification condition: 94 ℃ of 3min; 94 ℃ of 30s, 50 ℃ of 30s, 72 ℃ of 30s, 30 circulations; 72 ℃ of 10m.
Pcr amplification product carries out 1% agarose gel electrophoresis, reclaims test kit with gel and reclaims the purpose fragment about 500bp.
3, the structure of SCN cgh-1RNAi expression vector
1. use the purpose fragment of restriction enzyme Sac I and Kpn I double digestion step 2, reclaim enzyme and cut product.
2. use restriction enzyme Sac I and Kpn I double digestion carrier pZH01, reclaim carrier framework (about 11.5Kp).
3. step enzyme is 1. cut product and be connected, obtain the recombinant plasmid first with step carrier framework 2..
4. use the purpose fragment of restriction enzyme XbaI and Sal I double digestion step 2, reclaim enzyme and cut product.
5. use restriction enzyme Xba I and Sal I double digestion step recombinant plasmid first 3., reclaim carrier framework (about 12Kp).
6. step enzyme is 4. cut product and be connected, obtain recombinant plasmid second, i.e. the SCNcgh-1RNAi expression vector with step carrier framework 5..According to sequencing result; It is following that SCN cgh-1RNAi expression vector is carried out structrual description: skeleton carrier is pZH01; Between the Xba of skeleton carrier I and Sal I restriction enzyme site, insert double chain DNA fragment A (like sequence 2 from shown in 5 ' the terminal 523-1090 position Nucleotide), between the KpnI of skeleton carrier and Sac I restriction enzyme site, inserted double chain DNA fragment B; Double chain DNA fragment B and double chain DNA fragment A are reverse complementary sequence.The structural representation of SCN cgh-1RNAi expression vector is seen Fig. 4.
Two, the conversion of soybean root system is identified with expression
1, with SCN cgh-1RNAi expression vector transforming agrobacterium rhizogenes K599, obtains the Agrobacterium of recombinating.The PCR of reorganization Agrobacterium bacterium liquid identifies that the primer of Primer-F and Primer-R composition (adopt to) electrophorogram sees Fig. 5.Reorganization Agrobacterium bacterium liquid has increased and target fragment band of the same size, explains that SCN cgh-1RNAi expression vector has been integrated into Agrobacterium rhizogenes K599.
With carrier pZH01 transforming agrobacterium rhizogenes K599, obtain contrasting Agrobacterium.
2, soybean root system transforms
(1) conversion of experimental group soybean
HSBC Branch No. 1 soybean seed disinfection, disinfection Zhi sown in stone; 5 days, seedling germination; recombinant Agrobacterium was inoculated seedlings cotyledon node, and then transplant the seedlings, moisturizing growth; 2-3 weeks, the hair root appear; when the hair root 5-10 cm, cut the original root, transplanted into the soil (d6cm × h12cm plastic cup) growth of each plant a plastic cup.
(2) conversion of control group first soybean
To contrast Agrobacterium replaces the reorganization Agrobacterium to carry out step (1) operation.
(3) conversion of control group second soybean
Carry out the operation of step (1), but do not inoculate reorganization Agrobacterium bacterium liquid.
3, identify the expression of hairly root gus gene
In the step 2, after Agrobacterium infected for 4 weeks, the root system of getting experimental group soybean and control group second soybean respectively carried out histochemical stain, identified the expression of gus gene.Concrete steps are following: root system is put into 37 ℃ of dark overnight cultures of X-Gluc solution; At room temperature use 70% (volume ratio) aqueous ethanolic solution to clean 30min then; Then root system is put into water, the blueness under the white background is GUS and expresses the site.
The result sees Fig. 6.It is blue that the root system of control group second soybean does not become, and it is blue that the root of experimental group soybean all becomes, transformation efficiency about 100%.The GUS coloration result shows, adopts the rich technology of recombinant plasmid importing Agrobacterium rhizogenes soybean transformation section effective.
4, RT-PCR analyzes the expression of SCN cgh-1 fragment at soybean root
In the step 2, after Agrobacterium infected for 4 weeks, get the root system of 1 strain control group first soybean and 5 strain experimental group soybean; Extract total RNA (see figure 7); Reverse transcription becomes cDNA, and the cDNA template is all diluted 5 times, carries out the cgh-1 Gene RT-PCR amplification primer of Primer-F and Primer-R composition (adopt to).With tubulin gene adjustment template consumption, when the brightness basically identical of amplified production, can confirm that template concentrations is consistent.
Trizol Reagent is available from Invitrogen company, and the reverse transcription test kit is available from precious biotechnology (Dalian) ltd, TaKaRa Code:D6210A.PCR reaction system (25 μ l): cDNA 2 μ l, Primer-F 1 μ l, Primer-R 1 μ l, 2 * TagPCR Master Mix, 12.5 μ l, ddH
2O 8.5 μ l.Pcr amplification program: 94 ℃ of 4min; 94 ℃ of 40s; 52 ℃ of 40s; 72 ℃ of 50s (30cycles); 72 ℃ of 5min; 10 ℃ of 1h.
Among Fig. 7, the banding pattern of the RNA 28S ribosome-RNA(rRNA) of carrying and 18S ribosome-RNA(rRNA) more clear, no conditions of streaking explains that the RNA that extracts has integrity preferably.
Amplification is as shown in Figure 8, and control group first soybean does not amplify the purpose band, and 5 strain experimental group soybean root systems all amplify the target stripe of 568bp.Show that SCN cgh-1 gene fragment has obtained correctly transcribing in the soybean root system genome.
5, the resistance of soybean SCN is identified
In the step 2, after Agrobacterium infected for 4 weeks, in each plastic cup, add the pathogenic liquid (every milliliter of ovum that contains No. 4 physiological strains of 400 soybean SCNs of having an appointment) of 5ml.Keep the soil moisture at 24-30 ℃ behind the pathogenic liquid of inoculation, calculate the cyst number after 30 days.Experiment is carried out three times and is repeated results averaged.Soybean strain system to the resistance level of soybean SCN generally with parasitic exponential representation.Parasitic index be high anti-kind between 0-9, resists between the 10-30 being, and between the 31-60 middle sense, be susceptible variety greater than 60.
Parasitic index=(on the every gram root of test plant on the every gram root of cyst number/soybean susceptible variety Lee of giving birth to the cyst number of giving birth to) * 100.
Each is organized parasitic exponential statistics and sees table 5.
Table 5 is respectively organized parasitic exponential statistics
|
The experimental group soybean |
Control group first soybean |
Control group second soybean |
Soybean susceptible variety Lee |
Inoculation strain number |
32 |
37 |
5 |
22 |
Average cyst number/g root |
65 |
111 |
109 |
276 |
The P value |
0.0002 |
|
|
|
Parasitic index |
23 |
40 |
39 |
100 |
The IP qualification result |
In anti- |
Middle sense |
Middle sense |
|
Worm's ovum number/g root |
8798 |
18811 |
|
|
The P value |
<0.0001 |
|
|
|
Single cyst worm contains the number of ovum |
128 |
194 |
|
|
The P value |
0.122 |
|
|
|
The result of table 5 shows; The number that imports cyst on the every gram root of plant of SCN cgh-1RNAi expression vector significantly reduces, the number that the worm's ovum number significantly lowers, single cyst contains ovum on every gram root also reduces greatly, and promptly the SCNcgh-1RNAi expression vector has suppressed the ability of growing and the prolificacy of SCN.According to parasitic index judgement criteria; Can know by table 5; The parasitic index that contains the experimental group soybean is 23; Parasitic index standard of perfection is anti-in being, because the big rich No. 1 long-term qualification result of pulse family proves the kind (parasitic index about 40) of No. 4 physiological strains of sense soybean SCN in, so changing over to of SCN cgh-1RNAi expression vector significantly improved the resistance of soybean root system to SCN.