CN102351950A - Rice drought-tolerance related transcription factor gene OsWTF1, and coding protein and application thereof - Google Patents

Abstract

The invention discloses a rice drought-resistance-related transcription factor gene OsWTF1 and its encoded protein and its application. The rice drought-resistance-related protein is the protein of (a) or (b): (a) from SEQ ID No: 2 in the sequence table A protein composed of the amino acid sequence shown; (b) the amino acid sequence of SEQ ID No: 2 in the sequence table undergoes substitution and/or deletion and/or addition of one or several amino acid residues and is related to plant stress resistance Proteins derived from (a). The rice drought-resistant related protein and its coding gene can be used to breed drought-resistant rice.

Description

Rice drought resistance-related transcription factor gene OsWTF1 and its encoded protein and application

technical field

The invention relates to the field of plant biotechnology, in particular to the isolation, cloning, functional verification and application of a rice transcription factor family AP2/ERF superfamily ERF subfamily wax-related gene.

Background technique

Rice is the most important food crop in my country, and rice is also the largest household in agricultural water consumption. In recent years, due to the influence of the ecological environment and climate warming, the lack of water resources has seriously restricted the production of grain in my country, and has become the main reason for the reduction of rice production. In order to breed new drought-resistant rice strains, people try to understand the response mechanism of plants to drought through biotechnology, and use molecular biology methods to improve the drought resistance of plants. Studies have shown that plants can secrete wax on the surface of the cuticle or in the cuticle to limit the loss of non-stomatal water in plants, and have the effect of water retention and drought resistance. On the other hand, in-depth research on plant transcription factors has also found that ERF transcription factors containing 58-59 highly conserved amino acid domains can participate in the regulation of plant responses to biotic and abiotic stresses, and improve plant resistance to drought, pests, Tolerance to stress such as low temperature stress. In view of the increasingly serious water shortage problem that our country is facing, the discovery of ERF transcription factors that regulate the expression of rice waxy related genes will be of great significance to the cultivation of new drought-resistant rice varieties and the improvement of rice yield.

Contents of the invention

The object of the present invention is to provide a waxy transcription factor gene and its encoded protein related to rice drought resistance. The waxy transcription factor gene related to rice drought resistance provided by the present invention is called OsWTF1 (homologous to WIN1 in Arabidopsis thaliana), and the number of this gene in the rice genome database TIGR is Os02g0202000, encoding a gene containing "AP2" The ERF-type rice wax metabolism transcription factor of the structural domain, the CDS of the gene is 618bp in length, and encodes a protein of 205aa. So far, there is no research report on the function of OsWTF1. The gene described in the present invention is the gene numbered Os02g0202000 in the rice genome database TIGR, which is one of the following nucleotide sequences:

1) The DNA sequence of SEQ ID No: 1 in the sequence table;

2) A polynucleotide encoding the protein sequence of SEQ ID No: 2 in the sequence listing;

3) A DNA sequence that has more than 90% homology with the DNA sequence defined by SEQ ID No: 1 in the sequence listing and encodes the same functional protein.

The DNA sequence of SEQ ID No: 1 in the sequence listing consists of 912 bases and contains 2 exons, which are from the 154th to the 236th base at the 5' end and from the 357th to the 5' end at the 5' end. 892 bases. The sequence encodes the nucleotide residue sequence of SEQ ID No: 2.

The encoded protein OsWTF1 of the gene OsWTF1 related to rice drought tolerance is a protein with the amino acid residue sequence of SEQ ID No: 2 in the sequence table, or the amino acid sequence of SEQ ID No: 2 through one or several amino acid residues A protein derived from SEQ ID No: 2 that is substituted, deleted or added and has the same activity as the amino acid residue sequence of SEQ ID No: 2.

The amino acid residue sequence of SEQ ID No: 2 in the sequence listing is a protein consisting of 205 amino acid residues.

The expression vector, transgenic cell line and host bacterium containing the gene OsWTF1 of the present invention all belong to the protection scope of the present invention.

Primer pairs for amplifying any fragment of OsWTF1 are also within the protection scope of the present invention.

Another object of the present invention is to provide a method for improving drought resistance of plants.

The method for improving plant drought resistance provided by the present invention is to construct an overexpression vector of the gene OsWTF1 related to drought resistance and introduce it into plant tissues or cells to improve the drought resistance of plants.

The starting vectors used to construct the plant expression vectors include binary Agrobacterium vectors and vectors that can be used for plant microprojectile bombardment and the like. Utilizing any carrier capable of directing the expression of peripheral genes in plants, overexpressing the OsWTF1 gene of the present invention in plants exhibits drought tolerance characteristics.

When the gene of the present invention is constructed on a plant expression vector, any strong promoter or inducible promoter can be added before its transcription start nucleotide, and an enhancer can also be used.

The expression vector carrying the OsWTF1 gene of the present invention can be transferred into plant cells by conventional biotechnology methods such as Ti plasmid, Ri plasmid, plant virus vector, direct DNA transformation, microinjection and electroporation, and cultivate plants with improved drought resistance . The transformed plant host can be monocotyledonous plants such as rice, corn, wheat, etc., and is also suitable for dicotyledonous plants such as tobacco and soybean, and cultivates drought-resistant plant varieties.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the result of homology comparison between rice OsWTF1 protein and its homologous protein in Arabidopsis thaliana using ClustalW software (open access software).

Among them: black indicates highly conserved amino acids.

Fig. 2 is an analysis diagram of the conserved domain of the protein encoded by the OsWTF1 gene.

Figure 3 is the full-length cDNA clone of OsWTF1

From left to right in the figure: M, molecular weight marker; 1, 5'RACE amplification product; 2, 5'RACE amplification negative control; 3, 3'RACE amplification product; 4, 3'RACE amplification product Added negative control. 5'RACE amplified to obtain a fragment of about 750bp, 3'RACE amplified to obtain a fragment of about 300bp, the 5'RACE and 3'RACE products were gel-cut and recovered, and transferred to pGEM-T Easy Vector, obtained by sequencing and splicing The full-length cDNA is 791bp, the length of the coding region is 618bp, and the predicted encoded protein is 205aa. The cloned full-length cDNA was registered in Genbank (DQ468387, ABE98440).

Fig. 4 is a graph showing the gene expression analysis of OsWTF1 under drought and ultraviolet radiation conditions.

Among them: CK represents the expression of OsWTF1 gene in untreated Nipponbare leaves, 1 represents the expression of OsWTF1 gene in rice leaves after drought treatment, and 2 represents the expression of OsWTF1 gene in rice leaves under UV treatment. The expression of OsActin gene was used as an internal reference (one round of expression of OsActin, 28cycles).

Fig. 5 is a diagram showing the results of PCR and RT-PCR detection of OsWTF1 overexpression transgenic plants.

Among them: A: PCR detection of OsWTF1 overexpression transgenic plants. P indicates that the plasmid containing the OsWTF1 gene fragment is used as a positive control; 1 and 2 are non-transgenic plants used as a recessive control; 3-16 are independent transgenic plant lines.

B: RT-PCR detection of OsWTF1 overexpression transgenic plants. P represents a plasmid containing the OsWTF1 gene fragment; CK1 and CK2 are non-transgenic control plants, and the rest are independent transgenic lines, and the OsActin gene is used as an internal reference.

Fig. 6 is a scanning electron microscope observation result of waxy crystals in the leaf epidermis of rice plants with OsWTF1 overexpression.

Among them: a ₁ is the ventral surface of the leaf of the wild-type control plant; a ₂ is the back of the leaf of the wild-type control plant; b ₁ is the ventral surface of the leaf of the OsWTF1-overexpressed transgenic rice; b ₂ is the back of the leaf of the OsWTF1-overexpressed transgenic rice.

Fig. 7 is an analysis diagram of the chlorophyll extraction rate of leaves of transgenic plants overexpressing OsWTF1.

Fig. 8 is a diagram showing the resistance response of OsWTF1 transgenic plants to drought. It is a drought-resistant treatment experiment on rice plants at the tillering stage cultivated in the greenhouse.

Among them: a is the wild type (WT) Nipponbare plant, b is the OsWTF1 transgenic plant.

The figures are: before drought treatment, the comparison between OsWTF1 overexpression transgenic rice b ₁ and wild type a ₁ ;

Comparison of OsWTF1 overexpression transgenic rice b ₂ and wild type a ₂ after one week of drought treatment;

Comparison of OsWTF1 overexpression transgenic rice b ₃ and wild type a ₃ after one week of drought treatment followed by one week of rewatering.

Detailed ways

The experimental methods in the following examples are conventional methods unless otherwise specified.

Example 1. Acquisition of plant stress resistance-related protein OsWTF1 and its encoding gene

The results of Microarray analysis showed that the rice Os02g0202000 gene is an AP2-type transcription factor gene, encoding an ERF-type rice wax metabolism transcription factor containing "AP2" domain. Using the BLAST program, it was found that it is highly homologous to WIN1 in Arabidopsis. The study of WIN1 showed that it is a transcription factor involved in the wax metabolism pathway. So we named the Os02g0202000 gene OsWTF1. The 5'RACE amplification primers: WTF1R1 and WTF1XbaR, and the 3'RACE amplification primers: WTF1F1 and WTF1BamF were designed according to the published sequence of the rice BAC library AP004869 to amplify the full-length cDNA of the OsWTF1 gene.

The amplification conditions were operated according to the instructions of SMART ^TM RACE cDNA Amplification Kit.

5'RACE: Under the action of Superscript III reverse transcriptase, 4 μL of rice young panicle total RNA was used as a template, and 5'CDS primer and SMARTII A oligo were used as primers to synthesize single-stranded cDNA of 5'RACE.

3'RACE: Under the action of Superscript III reverse transcriptase, 4 μL of rice young panicle total RNA was used as a template, and 3'CDS primer A, DTT, dNTP and First-strand Buffer were added, and added at 42°C for 1.5h to synthesize 3'RACE single-stranded cDNA.

After 5'RACE single-stranded cDNA and 3'RACE single-stranded cDNA were synthesized, the reverse transcription product was diluted 100 times. 5'RACE used 5'RACE single-stranded cDNA as a template, UPM and WTF1R1 as primers; 3'RACE used 3' RACE single-stranded cDNA was used as a template, and UPM and WTF1F1 were used as primers for landing PCR. The reaction conditions were: 94°C for 5s, 72°C for 3min, 5 cycles; 4°C for 5s, 70°C for 10s, 72°C for 3min, 5 cycles; 94°C for 5s, 68°C for 10s, 72°C for 3min, 25 cycles; store at 4°C. The first-round PCR products were subjected to PCR reactions with UPM, WTF1XbaR and UPM, WTF1BamF respectively. The amplification conditions were 94°C for 3 min; 94°C for 30 s, 60°C for 30 s, 72°C for 1 min, and 35 cycles; 72°C for 5 min; and stored at 4°C.

The PCR product was detected by agarose gel electrophoresis, the 5'RACE and 3'RACE fragments were recovered with an agarose gel recovery kit, the recovered fragments were ligated with the vector pGEM-T Easy, and the ligated products were transformed into Escherichia coli DH5α competent cells According to the carbenicillin resistance marker on the pGEM-T Easy vector, positive clones were screened to obtain recombinant plasmids containing recovered fragments. Using the T7 and SP6 promoter sequences on the recombinant plasmid vector as primers to determine its nucleotide sequence, combined with Figure 3, the sequencing results showed that the protein coding region fragments at the 5' and 3' ends of the OsWTF1 gene were amplified, and then The full-length cDNA of the full-length OsWTF1 gene was obtained from two 3'-RACE and 5'-RACE products with overlapping sequences. The sequence of the protein coding region of the OsWTF1 gene is shown in SEQ No: 3, which consists of 618 deoxyribonucleotides and encodes the protein shown in SEQ No: 2.

Specific primer information is as follows:

Upstream primer WTF1BamF 5'-AT ATCTCTGCCTCCCCTGTCCTTC-3', the bold underlined base is the BamHI restriction site,

Downstream primer WTF1XbaR 5'-AT CGTCGTTTCATCCAAAGCCTTTC-3', the bold underlined base is the XbaI restriction site;

Upstream primer WTF1F1: 5'-GACTCCAACTGGGTGATGACGGTG-3',

Downstream primer WTF1R1: 5'-TTGCTACGGGCGTCCTGGTCTGC-3'.

Example 2, Blast comparison of OsWTF1 gene, subcellular localization and conserved domain analysis of encoded protein

Referring to Figure 1 and Figure 2, the homology analysis was performed by the CLUSTAL W and DNAMAN software of the http://www.ncbi.nlm.nih.gov/BLAST/ website. The homology between rice OsWTF1 gene and Arabidopsis thaliana wax metabolism transcription factor gene WIN1 (SHN1) is high, the amino acid homology between OsWTF1 and Arabidopsis gene WIN1 (at1g15360) is 61%, and the amino acid homology with At5g25390 is 54%, and the amino acid homology with At5g11190 is 55%. The Arabidopsis genes WIN1(SHN1, at1g15360), At5g11190, and At5g25390 genes are genes related to the regulation of wax metabolism. It is speculated that OsWTF1 gene may be related to rice wax metabolism. Through the analysis of the subcellular localization analysis software on the http://wolfpsort.org/ website, it was found that 11 known genes with high homology to OsWTF1 were located in the nucleus, and 2 were located in the chloroplast. It was preliminarily determined that the protein encoded by the OsWTF1 gene was localized in the nucleus. According to the sequence conserved region of rice OsWTF1 gene encoded protein, use the software provided by http://www.ncbi.nlm.nih.gov/Structure/cdd/wrpsb.cgi for functional analysis, and use http://swissmodel.expasy.org/ The software predicts the protein structure and finds that OsWTF1 has an AP2 domain at 6-66aa, which belongs to the EREF transcription factor.

Example 3, Analysis of OsWTF1 Gene Expression Differences under Stress Conditions

In order to test the response of OsWTF1 gene under stress conditions, rice leaves were treated with drought and ultraviolet radiation, and the expression of OsWTF1 gene in the treated plants was detected.

Conventionally cultivated rice was divided into three groups at the end of tillering stage. One group was the control group, which was grown under natural light; the ultraviolet treatment group was provided with UVB radiation (15W, Shanghai Gucun Optoelectronic Instrument Factory) under natural light conditions with an additional UVB tube. The ultraviolet lamp tube is positioned at 20-30cm above the plant, and the UVB radiation photoperiod is 8h/d (the treatment time is 9:00-17:00 every day), and the treatment lasts for one week. The drought treatment group was grown under natural light plus 6 days of drought treatment. After the treatment, the leaves were taken and the total RNA was extracted with Trizol extract from Invitrogen Company, and the expression of OsWTF1 gene in the leaves after stress treatment was analyzed by RT-PCR using the total RNA as a template. Reverse transcription system: 2μL 50ng/μL Olig(dt), 4.0μL 5X first strand buffer, 0.4μL 100mmol/L DDT, 2.0μL 10mmol/L dNTP, 1.0μL M-MLV 200U/μL, then add DEPC-treated H2O to 20 μL. Water bath at 37°C for 1h. Place at 95°C for 5 minutes to inactivate M-MLV, add 2 μL TE (pH=8.0) to synthesize single-stranded cDNA. Using the synthesized first-strand cDNA as a template, the expression of OsWTF1 gene was detected by WTF1BamF and WTF1XbaR. It was found that under normal cultivation conditions, the expression of OsWTF1 gene in rice leaves was low, and the reverse-transcribed cDNA underwent two rounds of PCR (the first round was 28 cycles and the second round was 30 cycles).

The OsActin gene was used as an internal reference, and the reaction conditions were: pre-denaturation at 94°C for 3 min; 94°C for 30 sec, 60°C for 30 sec; 72°C for 35 sec, 28 cycles; 72°C for 10 min. Its specific primers are as follows:

ActinBamF: 5'-ATGGATCCAGGTAATAAGATTCTTCAACAC-3'

ActinSpeR: 5'-ATACTAGTACCTGGAAACACACAAGACA-3'

As shown in Figure 4, after a period of ultraviolet and drought treatment, the expression of OsWTF1 gene in rice leaves was significantly increased compared with the control, and the increase of OsWTF1 expression was more significant in drought treatment than in ultraviolet treatment.

Embodiment 4, construction and transformation of OsWTF1 gene overexpression vector

In order to better clarify the function of the OsWTF1 gene, the applicant overexpressed it in rice, and verified the function of the OsWTF1 gene from the phenotype of the transgenic plant.

The overexpression vector construction method is as follows: the full-length OsWTF1 full-length cDNA (SEQ ID No: 3) was directional cloned into the downstream of the 35S promoter of the pCambia1300M vector, and used to construct a plant binary expression vector for the overexpression of rice 35S-OsWTF1. After being transformed into Agrobacterium EHA105 by the freeze-thaw method, it was introduced into the rice variety "Nipponbare" through the Agrobacterium-mediated genetic transformation method, and after pre-cultivation, infection, co-cultivation, and screening, it has hygromycin resistance callus, differentiation, rooting, seedling hardening and transplanting to obtain transgenic plants. The Agrobacterium-mediated rice genetic transformation method used the method reported by Qu et al. (Qu et al., 2006).

Example 5, Molecular detection of OsWTF1 gene overexpression transgenic plants

The OsWTF1 gene overexpression transgene molecular detection of the present invention adopts PCR and RT-PCR method to carry out.

5.1 PCR molecular detection at the DNA level of transgenic plants with overexpression of OsWTF1 gene

Extract rice genomic DNA by CTAB method: Cut about 100mg of rice leaves, grind them into powder with liquid nitrogen in a mortar, add 600μL DNA extraction buffer preheated at 60°C, keep warm in a 60°C water bath for 30-60min, and shake gently from time to time . Add 600 μL equal volume of chloroform/isoamyl alcohol, invert and mix well, and let stand at room temperature for 5-10 min to separate the aqueous phase and the organic phase. Centrifuge at 10000r/min for 30min at room temperature. Take the supernatant to another 1.5mL eppendorf tube, add one volume of isopropanol, mix well, place at -20°C for 30min, then centrifuge at 10000r/min for 10min; wash twice with 70% alcohol, dry in the air, add 100μL TE solution to dissolve .

PCR identification of OsWTF1 gene overexpression transgenic plants:

Take 100ng of hygromycin-resistant transgenic OsWTF1 rice plant genomic DNA, use HygF and HygR primers for PCR amplification to identify the hygromycin-encoding gene, use primers WTF1BamF and WTF1XbaR for PCR amplification identification, and set the overexpression plasmid as a positive control , Genomic DNA from non-transgenic plants was used as a negative control. As a result, as shown in A in Figure 5, all transgenic positive plants can amplify the DNA fragment of about 820bp with introns in the rice genome itself and the cDNA fragment of OsWTF1 full-length about 700bp inserted in the rice genome, but not Both the transgenic negative control plants and the transgenic negative plants could only amplify the DNA fragment of about 820 bp with intron in the rice genome itself, and the plasmid control could also amplify the OsWTF1 full-length cDNA fragment of about 700 bp. PCR detection obtained 22 positive plants transfected with OsWTF1 full-length cDNA.

5.2 RT-PCR molecular detection at the RNA level of transgenic plants with overexpression of OsWTF1 gene

Extract the total RNA of the young panicles of the positive plants detected at the DNA level and the total RNA of the non-transgenic Nipponbare young panicles, reverse transcribe into cDNA as a template, and use WTF1BamF and WTF1XaR as primers for PCR to analyze the expression of the target gene at the transcriptional level conditions, and the expression of the ACTIN gene was used as an internal reference. The methods of RNA extraction and RT-PCR reaction are the same as the RT-PCR method in Example 3. The results are shown in Figure 5, B. Compared with non-transgenic plants, OsWTF1 has been enhanced in some transgenic plants to varying degrees, and the No. 6 transgenic plant has strong expression, which can be used for further phenotypic identification.

Example 6, Scanning Electron Microscopic Observation of OsWTF1 Gene Overexpression Transgenic Plant Leaf Surface Wax

The fully expanded rice leaves of the overexpressed OsWTF1 gene transgenic plants and non-transgenic control plants in the same growth period were fixed with glutaraldehyde, stored in a refrigerator at 4°C, dehydrated and dried according to the requirements of the scanning electron microscope, and the samples were placed in Gold coating was sprayed on the JEOL JFC-1600 coating machine, observed and photographed under the JSM-6360LV scanning electron microscope. The results are shown in Figure 6: the back (b2) and ventral (b1) of leaves of OsWTF1 overexpressed plants had obvious thickening of epidermal wax, increased number of papillae, changes in the shape of papillae, and the height of papillae was significantly increased. Morphological changes such as a shape close to a cylinder, and these changes were more obvious in the ventral surface (b1) of the OsWTF1 transgenic rice leaves.

Embodiment column 7, the chlorophyll extraction rate of OsWTF1 gene overexpression transgenic plant leaf

The chlorophyll extraction rate of the leaves of transgenic OsWTF1 plants was determined by the percentage of the chlorophyll extraction amount in the total chlorophyll within a certain period of time.

Take the first functional leaf under the flag leaf of the OsWTF1 gene overexpression transgenic plant and the control plant (non-transgenic wild-type plant) at the same heading stage, wash it with tap water, weigh it, put 5g each into a triangular flask, add 30mL 80 % ethanol and shake occasionally in the dark. Take 400 μL of extracts from each sample every 10 minutes in the first hour, and then take 400 μL of extracts at 90 minutes and 120 minutes respectively, and measure their absorption values at λ664nm and λ647nm wavelengths. Calculate the total amount of chlorophyll (mmol/g)=7.93A664+19.53A647 according to the formula. The results are shown in Figure 7. As time goes by, the chlorophyll extraction rate of the transgenic and control wild-type plants gradually increases, but in the whole extraction process, the leaf chlorophyll extraction rate of the transgenic OsWTF1 gene plant is always higher than that of the control. Low, after alcohol extraction for 120min, about 80% of the chlorophyll in the leaves of the non-transgenic wild-type plants was extracted, while the extraction rate of the leaves of the transgenic OsWTF1 plants was less than 40%, indicating the permeability of the transgenic plants to chlorophyll reduce.

Embodiment 8, OsWTF1 gene overexpression transgenic plant response to drought treatment

On the premise of the results in Example 5, the present invention first carried out homozygous screening on the T3 generation of transgenic plants overexpressing the OsWTF1 gene. The specific steps are as follows: choose 30 seeds for each plant and remove the shells, sterilize the surface with 70% ethanol for 1min, disinfect with 30% bleach for 30min, wash with sterilized water 5 times, and sow them in 1/2MS (Murashige) containing hygromycin with sterile tweezers. & Skong) medium plate for screening, wild-type Nipponbare was used as a control, the culture condition was 28°C, the continuous light intensity was 2500lux, 16h light/8h dark. Two weeks later, the germination and survival rate were counted. In the present invention, plants with a 100% survival rate are considered homozygous by default, and each homozygous plant is individually sampled and subjected to corresponding molecular detection. The strains with consistent molecular detection and hygromycin screening results were used for subsequent phenotypic identification.

The present invention selects three independent overexpression transgenic pure rice for phenotype screening. The seeds of pure and transgenic lines and wild-type Nipponbare seeds were germinated and conventionally cultured until the middle tillering stage, and drought treatment was carried out without watering.

After one week of drought, as shown in Figure 8, OsWTF1 overexpressed plants basically maintained a normal growth state (b ₂ ), while most of the control wild type (a ₂ ) were wilted, with drooping leaves, showing severe drought stress.

After a week of drought and rewatering for a week, as shown in Figure 8, most of the leaves of the control wild-type plants were irreversibly dry, and only a few of the two tillers turned green, see a ₃ ; while OsWTF1 overexpression plants can all return to normal Growth state, see _b3 . The ability of plants to rehydrate after drought is also an important indicator of drought resistance. Drought and rewatering experiments showed that overexpression of OsWTF1 enhanced the drought tolerance of plants, and the results confirmed that OsWTF1 played an important role in the response to drought.

Claims (8)

1. A protein, which is the protein of (a) or (b): (a) a protein consisting of the amino acid sequence shown in SEQ ID No: 2 in the sequence listing; (b) The amino acid sequence of SEQ ID No: 2 in the sequence listing undergoes substitution and/or deletion and/or addition of one or several amino acid residues and is related to plant stress resistance. A protein derived from (a). 2. The protein according to claim 1, characterized in that: the substitution and/or deletion and/or addition of the one or several amino acid residues refers to the first amino acid to the 206th amino acid in SEQ ID No: 2 Amino acids are substituted and/or deleted and/or added. 3. The coding gene of the protein described in claim 1 or 2. 4. The gene according to claim 3, characterized in that: the following (a) or (b) or (c) gene: (a) its nucleotide sequence is the DNA molecule shown in SEQ ID No: 1 from the 1st to the 912th deoxyribonucleotide at the 5' end in the sequence listing, (b) its nucleotide sequence is the DNA molecule shown in SEQ ID No: 1 in the sequence listing, (c) A DNA molecule encoding said protein that hybridizes under stringent conditions to the DNA sequence defined in (a). 5. A recombinant expression vector containing the gene of claim 3 or 4. 6. The recombinant expression vector according to claim 5, characterized in that: the recombinant expression vector is pCambia1300M-OsWTF1, and the pCambia1300M-OsWTF1 inserts the gene described in claim 3 or 4 at the multiple cloning site of the pCambia1300M carrier The obtained recombinant expression vector. 7. A transgenic cell line or recombinant bacterium containing the gene of claim 3 or 4. 8. A method for cultivating drought-resistant rice, comprising introducing the recombinant expression vector according to claim 5 or 6 into rice cells to obtain drought-resistant rice.

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