Application of transcription factor b3-337 in improving quality of tomato fruits

Abstract

The application discloses application of a tomato B3-337 transcription factor in improving tomato quality, a gene coding the B3-337 transcription factor protein is named as a B3-337 gene, and a nucleotide sequence is shown as SEQ ID NO. 1. The application proves that the B3-337 is located in the cell nucleus by constructing a vector pFM3100GFP-B3-337. The transcription activity detection result proves that the B3-337 has transcription activation activity. It is found that the transcription factor is expressed in pericarp, seed, placenta and cauline stem at each stage of fruit ripening by RT-qPCR and GUS staining. The application obtains B3-337 gene overexpression plants by constructing a B3-337 overexpression vector. Compared with wild type, the tomato fruit of the B3-337 gene overexpression plant has increased soluble solid brix content, and the fruit is larger and heavier. It is indicated that the B3-337 transcription factor plays an important regulation role in positively regulating tomato fruit quality. The application lays a good genetic resource foundation for cultivation of a new high-quality tomato variety.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of biotechnology, and particularly relates to a protein B3-337 for regulating tomato fruit quality and application thereof. BACKGROUND

[0002] Tomato (Solanum lycopersicum) is one of the most important economic vegetable crops in the world, and is a classic model plant for studying fleshy fruit and quality formation. China's tomato yield has reached the first in the world, however, people in the past have paid too much attention to tomato yield and ignored quality. In recent years, with the high demand of people for the quality of agricultural products, consumers prefer high-quality tomatoes, and therefore, improving tomato fruit quality is crucial for the improvement of important horticultural traits of fruits and meeting the high demand of consumers. The regulatory role of transcription factors plays an important role in the formation of tomato fruit quality, in order to improve the quality of tomato fruits to meet market demand, the present application finds excellent transcription factors for regulating tomato fruit quality by means of molecular biology and other biological techniques, and cultivates excellent varieties through biological engineering means.

[0003] Soluble solids content can reflect the maturity of tomato fruit and is closely related to the flavor quality and nutritional value of the fruit, and is an important indicator of tomato fruit quality. It includes sugars (monosaccharides, disaccharides), organic acids, vitamins, and minerals, and other compounds that can be dissolved in water. The increase of soluble solids content is accompanied by fruit ripening, which can provide consumers with higher nutritional value and a wider choice of consumer markets, and promote the marketization of molecular breeding value. Previous studies have shown that transcription factors play an important role in regulating tomato fruit quality and size. For example, overexpression of SIBES1.8 leads to an increase in soluble sugar and organic acid content in fruits (Su D, Wen L, Xiang W, et al. Tomato transcriptional repressor S1BES1.8 influences shoot apical meristem development by inhibiting the DNA binding ability of SlWUS. The Plant Journal, 2022(2): 110. DOI: 10.1111 / tpj.15683.); overexpression of SlCDF4 gene affects cell division and expansion, thereby affecting fruit size (Renau-Morata B, Carrillo L, Cebolla-Comejo J, et al. The targeted overexpression of SlCDF4 in the fruit enhances tomato size and yield involving gibberellin signalling. Scientific Reports, 2020, 10(1). DOI: 10.1038 / s41598-020-67537-x.). The fructose and glucose content in SlHY5 knockout lines is significantly higher than that in wild type, indicating that SlHY5 can regulate sugar accumulation (Jia H M, Xu YP, Deng Y W, et al. Key transcription factors regulate fruit ripening and metabolite accumulation in tomato, P1ant Physiology, 2024, 195(3). DOI: https: / / doi.org / 10.1093 / plphys / kiae195). These studies show that biological breeding technology has great potential and application prospects in improving tomato quality.However, there is no report on the tomato transcription factor in regulating the soluble solid content of tomato fruit while not affecting the appearance quality (size and weight) of the fruit. SUMMARY

[0004] The present application aims to provide a transcription factor B3-337 for regulating the quality of tomato fruit and application of the transcription factor B3-337 in improving the quality of tomato fruit.

[0005] To achieve the above-mentioned purpose, the technical solution of the present application is as follows:

[0006] The present application finds a tomato B3-337 gene, the gene sequence number (Sequence ID) of which in NCBI is XM_004230585.5, the nucleotide sequence of which is shown in SEQ ID NO. 1, the length of the messenger RNA (mRNA) sequence of the GhRV8 gene is 1011 bp, and the length of the coding sequence of the B3-337 gene is 1011 bp.

[0007] Through cloning and preliminary research on the tomato B3-337 gene, the present application finds that the B3-337 has a certain influence on the quality of tomato fruit, and the tomato B3-337 gene is positively correlated with the quality of tomato fruit; that is, after overexpression of the gene, the quality of tomato fruit is improved. This can lay a certain genetic resource foundation for breeding of new high-quality tomato varieties.

[0008] The present application also constructs a series of plant expression vectors, expression vectors containing the above-mentioned gene, transgenic plant lines and host cells containing the above-mentioned vectors also fall within the protection scope of the present application in improving the quality of tomato fruit.

[0009] The most important purpose of the present application is to protect the above-mentioned transcription factor B3-337, the B3-337 gene encoding the transcription factor protein B3-337 and biological materials containing the above-mentioned coding sequence in improving the quality of tomato fruit.

[0010] The improvement of the quality of tomato fruit specifically shows that the soluble solid content of the B3-337 gene overexpression strain is higher, the fruit is larger, and the weight is heavier compared with the wild type.

[0011] In order to improve the quality of fruit, the present application also protects a new breeding method for improving the quality of tomato fruit, the method being to obtain fruit with higher quality than the target plant by regulating the expression of the B3-337 gene in the target plant.

[0012] The way of regulating the expression of the B3-337 gene in the target plant is overexpression or superexpression of the B3-337 gene.

[0013] The plant of interest of the present application is the cultivated species Solanum lycopersicum AC (Ailsa Craig).

[0014] The gene of interest, also referred to as target gene, is a gene that is used in genetic engineering design and manipulation for gene recombination, changing the characteristics of the recipient cell and obtaining the desired expression product. It can be the organism itself or from a different organism.

[0015] In addition, the person skilled in the art can easily mutate the B3-337 gene of the present application by using known methods, such as the methods of directed evolution and point mutation. Those nucleotides which are artificially modified and have 75% or higher identity with the nucleotide sequence encoding the transcription factor protein B3-337 are derived from the nucleotide sequence of the present application and are equivalent to the sequence of the present application, as long as they encode the same protein and have the same function. The primer pairs for amplifying the full length or fragments of the coding sequence encoding the protein B3-337 also fall within the protection scope of the present application.

[0016] In the above method for improving the quality of tomato fruits, the B3-337 gene overexpression plant is obtained by overexpressing the B3-337 gene in the plant genome, and the homozygous B3-337 gene overexpression plant is obtained from the offspring of the B3-337 gene overexpression plant. The homozygous B3-337 gene overexpression plant is the plant with higher quality fruits. The offspring of the homozygous B3-337 gene overexpression plant can be the offspring of the first selfing generation, the offspring of the second selfing generation, the offspring of the third selfing generation, etc., until the homozygous B3-337 gene overexpression plant is obtained. The fruits of the offspring of the homozygous B3-337 gene overexpression plant are high-quality tomato fruits.

[0017] The above method for improving the quality of tomato fruits is also applicable to other recipient plants having homologous genes with tomato. The recipient plants suitable for the present application are not particularly limited and include not only tomato but also other plants with high homology, such as various crops, ornamental plants or forestry plants, etc. The plants can be, but are not limited to, dicotyledonous plants, monocotyledonous plants, woody plants, rosaceous plants, rosaceous plants, peach, cruciferous plants, Arabidopsis plants, Arabidopsis, etc.

[0018] The "plant" of the present application includes the whole plant, the parent and offspring plants and different parts of the plant, including seeds, fruits, stems, buds, leaves, roots, flowers, tissues and organs, and the gene or nucleic acid of interest is present in these different parts. The "plant" mentioned herein also includes plant cells, suspension cultures, callus tissues, embryos, meristematic regions and pollen, and each of the foregoing objects contains the gene / nucleic acid of interest.

[0019] This invention includes any plant cell, or any plant obtained or obtainable by the methods described herein, as well as all plant parts and their propagules. This patent also includes transfected cells, tissues, organs, or whole plants obtained by any of the foregoing methods. The only requirement is that the offspring exhibit the same genotype or phenotypic characteristics, and that offspring obtained using the methods of this patent have identical characteristics.

[0020] This invention also extends to the harvestable parts of the plants as described above, but is not limited to seeds, fruits, and peels. It further relates to other derivatives of the plant after harvest, such as organic acids, sugars, lycopene, tomatine, volatile substances, vitamins, minerals, and proteins. This invention also relates to foods or food additives obtained from the relevant plants.

[0021] Advantages of this invention:

[0022] This invention discovered a novel transcription factor, B3-337, in tomatoes during the research process. Experiments showed that, compared with the wild type, B3-337 overexpression lines had higher soluble solids content, larger fruits, and heavier weights. In other words, the fruit quality of B3-337 overexpression lines was significantly better than that of wild-type materials, indicating that the B3-337 gene plays an important regulatory role in the formation of tomato fruit quality and has important guiding significance for the genetic improvement of tomatoes. Attached Figure Description

[0023] Figure 1 These are the subcellular localization results for B3-337.

[0024] Figure 2 This is the result of the transcriptional activity assay for B3-337.

[0025] Figure 3 These are the tissue-specific expression results of B3-337. Figure A shows the tissue-specific expression results of B3-337 detected by quantitative fluorescence; Figure B shows the tissue-specific expression results of B3-337 detected by GUS staining, with a scale bar of 1 cm.

[0026] Figure 4 This is the identification result of RNA level in plants after B3-337 overexpression.

[0027] Figure 5This analysis compares the soluble solids (BRI) content, size, and weight of fruits from B3-337 gene overexpression lines with those from wild-type plants. Figure A shows the fruit phenotype (Scalebar = 1 cm). Figure B shows the soluble solids content of fruits from B3-337 gene overexpression lines and wild-type plants after the same cultivation period under identical conditions. Figure C shows the width of fruits from B3-337 gene overexpression lines and wild-type plants after the same cultivation period under identical conditions. Figure D shows the length of fruits from B3-337 gene overexpression lines and wild-type plants after the same cultivation period under identical conditions. Figure E shows the weight of fruits from B3-337 gene overexpression lines and wild-type plants after the same cultivation period under identical conditions. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, unless otherwise specified, the specific experimental methods involved in the following embodiments are conventional methods or implemented according to the conditions recommended in the manufacturer's instructions.

[0029] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the experimental methods in the following embodiments are all conventional methods. Unless otherwise specified, the reagents and materials used can be purchased commercially.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0031] As used herein, the terms “nucleic acid,” “nucleic acid sequence,” “nucleotide,” “nucleic acid molecule,” or “polynucleotide” mean, but are not limited to, isolated DNA molecules (e.g., cDNA or genomic DNA), RNA molecules (e.g., messenger RNA), naturally occurring, mutant, synthetic DNA or RNA molecules, DNA or RNA molecules composed of nucleotide analogs, and single-stranded or double-stranded structures. These nucleic acids or polynucleotides include, but are not limited to, gene coding sequences, antisense sequences, and regulatory sequences of non-coding regions. These terms include a gene. “Gene” or “gene sequence” is broadly used to refer to a functional DNA nucleic acid sequence. Therefore, a gene may include introns and exons in a genomic sequence, and / or include coding sequences in cDNA, and / or include cDNA and its regulatory sequences. In particular embodiments, such as concerning isolated nucleic acid sequences, cDNA is preferred by default.

[0032] Unless otherwise specified, the first position of each nucleotide sequence in the sequence listing is the 5′ terminal nucleotide of the corresponding DNA / RNA, and the last position is the 3′ terminal nucleotide of the corresponding DNA / RNA.

[0033] During their research, the inventors of this invention discovered a novel transcription factor in tomatoes that regulates fruit quality, which they named B3-337 transcription factor. The gene encoding B3-337 transcription factor was named the B3-337 gene, with the gene number LOC101244128 and gene sequence ID XM_004230585.5 in the NCBI database.

[0034] Example 1: Cloning of the B3-337 gene

[0035] RNA was extracted from wild-type tomato fruits. Using cDNA obtained through reverse transcription as a template, the gene sequence obtained from the NCBI database was cloned by PCR using specific primers designed with Primer 5.0. The coding sequence of the B3-337 gene was then cloned (as shown in SEQ ID NO.1). The sequence of SEQ ID NO.1 is as follows:

[0036]

[0037]

[0038] Example 2: Subcellular localization of B3-337 protein

[0039] 1. Using the double-stranded DNA molecule shown in SEQ ID NO.1 of the sequence listing as a template, PCR amplification was performed using a primer pair composed of B3-337-GFPF and B3-337-GFPR, and the PCR amplification product was recovered.

[0040] B3-337-GFPF:

[0041]

[0042] B3-337-GFPR:

[0043]

[0044] 2. The pFM3100 vector was double-digested with restriction endonucleases EcoRI and SalI, and the vector backbone was recovered.

[0045] 3. The recovered product obtained in step 1 and the vector backbone obtained in step 2 were ligated using a homologous recombination kit to obtain the recombinant plasmid pFM3100-B3-337. The plasmid was then transformed into Agrobacterium.

[0046] 5. Pick a single clone containing the target gene from the bacterial plate and place it in 5 mL of YEP medium containing Rif and Kana. Shake gently overnight, then add it to 100 mL of LYEP (Rif + Kana) medium and incubate at 28°C with shaking at 200 rpm for about 8 hours. Measure the OD of the culture after shaking. 600 When the pH is 0.5-0.8, collect the bacterial suspension at 4000 rpm for 5 minutes, and resuspend the bacterial cells in resuspension buffer until the OD value is reached. 600 Set the bacterial suspension to 1 and let it stand at room temperature for 2-3 hours.

[0047] 6. Take tobacco leaves that have grown for 3-4 weeks, and use your thumb to press the syringe to inject the bacterial solution into the leaves from the lower epidermis.

[0048] 7. After culturing tobacco in the dark for 2 days, the expression of GFP in tobacco epidermal cells was observed using a laser scanning confocal microscope (LSM510META, Zeiss). The objective lens magnification was 20x, the excitation wavelength was 488nm, the bandpass BP was 505-530nm, and the long pass LP was 560nm.

[0049] Cellular results under laser scanning confocal microscopy are shown below. Figure 1 The results showed that the B3-337-GFP signal completely overlapped with the cell nucleus and the nuclear dye DAPI signal, indicating that the B3-337 transcription factor is located in the cell nucleus.

[0050] Example 3B3-337 Transcriptional Activity Detection

[0051] 1. Using the double-stranded DNA molecule shown in SEQ ID NO.1 of the sequence listing as a template, PCR amplification was performed using primer pairs consisting of B3-337-GAL4BDF and B3-337-GAL4BDR, and the PCR amplification products were recovered.

[0052] B3-337-GAL4BDF:

[0053]

[0054] B3-337-GAL4BDR:

[0055]

[0056] 2. The GAL4BD vector was double-digested with restriction endonucleases EcoRI and SalI, and the vector backbone was recovered.

[0057] 3. The recovered product obtained in step 1 and the vector backbone obtained in step 2 were ligated using a homologous recombination kit to obtain the recombinant plasmid GAL4BD-B3-337. The plasmid was then transformed into Agrobacterium.

[0058] 4. Extract Arabidopsis protoplasts and transform them in 2 mL round-bottom centrifuge tubes by adding reporter gene vector plasmid 35S-LUC and internal control pTRL plasmid in a ratio of 6:6:1.

[0059] 5. Transcriptional Activity Assay: Transcriptional activity was assessed using the Dual-luciferase reporter assay kit (Promega) on a GloMax 20 / 20 luminescent detector (Promega). LUC activity was used to determine the transcriptional activation or repression activity of the target gene. Results showed that the ratio of relative luciferase activity of GAL4BD-B3-337 was significantly higher than that of the control GAL4BD (…). Figure 2 This indicates that the GAL4BD-B3-337 transcription factor has transcriptional activation activity.

[0060] Tissue-specific expression analysis of Example 4B3-337

[0061] I. Quantitative Detection of Tissue-Specific Expression of B3-337

[0062] Fruits at four different stages—mature green stage (MG), breaker stage (BR), orange ripe stage (OR), and red ripe stage (RR)—cultivated in a greenhouse (culture conditions: day / night temperature: 25 / 18℃; relative humidity: 50-60%; light / dark duration: 16h / 8h) were selected as materials. Pericarp, stele, placenta, and seeds were harvested, and RNA was extracted from each. cDNA from these tissues was obtained through reverse transcription, diluted 10-fold, and used as templates. The expression level of the B3-337 gene in each stage and tissue was detected using qRT-PCR. The experimental results are as follows: Figure 3 As shown in Figure A: The relative expression levels of the gene in the pericarp tissue during the MG stage were set as the control. The B3-337 gene was expressed in the pericarp, septum, placenta, seeds, and locular tissue and seeds at all four stages of tomato fruit. Specifically, the expression level of B3-337 was higher in all tissues during the fruit ripening stage.

[0063] II. GUS staining detection of tissue-specific expression of B3-337

[0064] 1. Using the tomato genome as a template, the sequence 2000 bp upstream of the start codon of B3-337 was cloned. PCR amplification was performed using a primer pair consisting of B3-337-proF and B3-337-proR, and the PCR amplification product was recovered. Homologous recombination was used to construct the pQB-V3 vector, and then the pGWB3 expression vector was constructed using the Gateway method, completing the construction of the pB3-337::GUS expression vector.

[0065] B3-337-proF:

[0066]

[0067] B3-337-proR:

[0068]

[0069] 2. The constructed vector was genetically transformed into tomatoes to obtain pB3-337::GUS transgenic tomatoes. Positive seedlings were identified through genomic DNA level identification, and tissue-specific expression of B3-337 was detected by GUS staining using transgenic lines containing the GUS reporter gene.

[0070] 3. Analysis by GUS staining ( Figure 3 B) It was found that the B3-337 gene showed strong GUS signals in the pericarp, septum, placenta, seeds, and locular tissue and seeds at four stages of tomato fruit, which was consistent with the results of quantitative detection of tissue-specific expression of B3-337.

[0071] Example 5: Functional identification of the B3-337 gene

[0072] I. Construction of B3-337 gene overexpression vector

[0073] 1. Amplification of the target gene B3-337

[0074] pK2-35S-B3-337-F and pK2-35S-B3-337-R were synthesized, and the B3-337 gene shown in SEQ ID NO.1 was amplified by PCR.

[0075] pK2-35S-B3-337-F:

[0076]

[0077] pK2-35S-B3-33 7-R:

[0078]

[0079] 2. Using the Gateway method, the pK2-35S-B3-337 recombinant vector was obtained, and the pK2-35S-B3-337 recombinant vector was sequenced and identified.

[0080] II. Obtaining B3-337 gene overexpressing plants

[0081] 1. Take the B3-337 gene overexpression vector constructed in step one, and introduce it into Agrobacterium GV3101 to obtain recombinant Agrobacterium.

[0082] 2. First, disinfect the tomato seeds, then sow them on 1 / 2 MS plates. Place them in a light incubator and wait for germination.

[0083] 3. About 6-8 days after sowing, the seeds germinate and the cotyledons flatten. Cut off the cotyledons and soak them in MS liquid medium for 1 hour. Then, blot the remaining medium on the cotyledons with sterilized filter paper and place them on A1 solid medium (MS + 1 mg / L IAA + 1.75 mg / L ZT) for pre-culture for 1 day.

[0084] 4. Inoculate the recombinant Agrobacterium obtained in step 1 into the infection solution and adjust the concentration to OD. 600 =1.8-2.0. Resuspend the bacterial cells in 40 mL MS salt medium. Immerse the pre-cultured cotyledons in the Agrobacterium tumefaciens resuspended in MS salt medium for 15 min, blot off excess bacterial solution with sterilized filter paper, and return to the original medium for co-culturing for 2 days.

[0085] 5. Afterward, transfer the cotyledons to A2 resistance medium (MS + 1.0 mg / L IAA + 1.75 mg / L ZT + 75 mg / L Kan + 200 mg / L Tim). Incubate at 26℃ (16hr light) / 18℃ (8hr darkness) for one week, then transfer to A2 medium (7-10 days), and then incubate in the dark for another two weeks.

[0086] 6. Change the culture medium every three weeks until callus forms. After callus formation, transfer it to A3 medium (MS + 1.0 mg / L IAA + 1.75 mg / L ZT + 50 mg / L Kan + 200 mg / L Tim) to induce budding and seedling formation.

[0087] 7. After the callus tissue differentiates into growth points, use a knife to cut off the growth points and transfer them to A4 medium (MS + 50 mg / L Kan + 200 mg / L Tim) for root selection.

[0088] 8. Identify and screen positive transformation seedlings, and transplant normally growing plants into nutrient soil for cultivation, which are the T1 generation plants.

[0089] 9. Screen for plants overexpressing the B3-337 gene from T1 generation plants.

[0090] Specific steps: Take plant leaves, extract genomic DNA using the CTAB method, perform PCR amplification using primer pairs consisting of primers F and R, then recover the PCR amplification products and sequence them, and screen plants overexpressing the B3-337 gene based on the sequencing results.

[0091] Primer F: 5'-ttactattctagtcgacctgcaggc-3';

[0092] Primer R: 5'-tctagcatggccgcgggata-3'.

[0093] 10. Self-pollinate the B3-337 gene overexpressing plants obtained in step 9 and harvest seeds.

[0094] 11. Sow the seeds harvested in step 10 on solid 1 / 2 MS medium containing 50 mg / L kanamycin. After culturing for 10 days, transplant the normally growing plants into nutrient soil for further cultivation. These are the T2 generation plants.

[0095] 12. T3 generation plants obtained by self-pollination of a certain T2 generation plant were all homozygous B3-337 overexpressing plants. Individual T3 overexpressing plants were planted, and leaves from the same location were collected. RNA was extracted and quantitatively detected to identify RNA levels. The quantitative primers were RTB3-337F and RTB3-337R. The results of RNA level identification in the B3-337 overexpressing plants are shown below. Figure 4 The expression levels of OE1, OE4, OE6, OE7, and OE8 were all significantly increased.

[0096] Primer RTB3-337F:

[0097] Primer RTB3-337R:

[0098] The B3-337 gene overexpression lines were ultimately selected as OE1, OE4, and OE8 for subsequent experiments.

[0099] III. Phenotypic Identification of Fruits from Tomato B3-337 Gene Overexpression Lines

[0100] Phenotypic photographs were taken of B3-337 gene overexpression lines OE1, OE4, OE8, and wild-type plants. Figure 5 A) and identification, including the Brix content of soluble solids in tomato fruit (A) Figure 5 B) Fruit width ( Figure 5 C) Length Figure 5 D) and weight ( Figure 5E). As shown in the figure, after being cultured for the same number of days under suitable conditions, the brix content, fruit size, and weight of the B3-337-OE1, OE4, and OE8 overexpression lines were significantly higher than those of the wild type.

[0101] These results indicate that, under suitable conditions and within the same time frame, fruits from B3-337 overexpressing lines have higher sugar content than those from wild-type plants, while also exhibiting larger fruit size and weight. These results suggest that the B3-337 transcription factor can positively regulate tomato fruit quality.

[0102] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. Use of transcription factor B3-337 for improving the quality of tomato fruits, characterized in that, The nucleotide sequence encoding the B3-337 transcription factor gene is shown as SEQ ID NO. 1; the improved tomato fruit quality is specifically manifested in that, compared with the wild type, B3-337 The gene overexpression strain has higher soluble solid content, larger fruit, and heavier weight.

2. A gene expression cassette comprising the gene of claim 1, B3-337 The application of the gene expression cassette, the recombinant vector, the recombinant microorganism and the transgenic plant cell line in improving the quality of tomato fruits, wherein the improvement of the quality of tomato fruits is specifically manifested as that, B3-337 The soluble solid content of the gene overexpression strain is higher, the fruit is larger, and the weight is heavier.

3. A breeding method for improving the quality of tomato fruits, characterized in that, By promoting the target plant B3-337 Gene expression is used to obtain plants with fruit quality superior to that of the target plant. B3-337 The nucleotide sequence of the gene is shown in SEQ ID NO.1, and the target plant is tomato; the improvement in tomato fruit quality is manifested in: increased soluble solids content, larger fruit size, and increased weight.

4. The method for improving the quality of tomato fruits according to claim 3, characterized in that, promote B3-337 The manner in which the expression of the gene is increased is overexpression or overexpression.

5. The method for improving the quality of tomato fruits according to claim 4, characterized in that, Overexpressing a gene in a plant genome to obtain a gene overexpression plant B3-337 Overexpressing a gene in a plant genome to obtain a gene overexpression plant B3-337 Overexpressing a gene in a plant genome to obtain a gene overexpression plant B3-337 Obtaining a homozygous gene overexpression plant from the selfed progeny of the gene overexpression plant B3-337 Obtaining a homozygous gene overexpression plant from the selfed progeny of the gene overexpression plant B3-337 The homozygous gene overexpression plant is a plant with higher fruit quality.

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