Indica rice type OsNPF7.2 gene and application and method of encoding protein of indica rice type OsNPF7.2 gene in improving yield of japonica rice

Abstract

The invention discloses an indica rice type OsNPF7.2 gene and application and a method of encoding protein of the indica rice type OsNPF7.2 gene in increasing the yield of japonica rice. According to the invention, a nonglutinous rice type OsNPF7.2 gene overexpression strain and a japonica rice type OsNPF7.2 gene overexpression strain are obtained through a genetic engineering technology, and a japonica rice near-isogenic line carrying the nonglutinous rice type OsNPF7.2 gene is obtained through hybridization; phenotypic experiments find that in the mature period of rice, the tiller number and the yield of a single plant of an indica rice type OsNPF7.2 gene overexpression strain are higher than those of a japonica rice type OsNPF7.2 gene overexpression strain, and the effective tiller number, the single plant yield and the plot yield of a japonica rice near-isogenic line carrying the indica rice type OsNPF7.2 gene are higher than those of wild type japonica rice, so that the functional differentiation of the OsNPF7.2 gene can influence the yield of the rice; the indica type OsNPF7.2 gene can be used for increasing the yield of japonica rice. Experiments confirm that the indica type OsNPF7.2 gene has a potential application value in the aspect of japonica rice yield increase, and a theoretical basis and a guiding value are provided for cultivating high-yield japonica rice varieties by using the indica type OsNPF7.2 gene.

Description

Technical Field

[0001] This invention belongs to the fields of bioengineering and rice breeding technology, specifically the application and method of the OsNPF7.2 gene of indica rice and its encoded protein in improving the yield of japonica rice. Background Technology

[0002] Nitrogen is one of the essential macronutrients for plant growth. It is a crucial component of proteins, nucleic acids, some enzyme activity regulators, and cell structures, influencing energy exchange processes throughout the entire plant growth and development process. It plays an indispensable role in plant physiological development and reproductive growth. Nitrogen deficiency in plants manifests as poor development, pale green leaves, weakened photosynthesis, and difficulty in flowering and fruiting. Therefore, in agricultural production, the application of nitrogen fertilizer is a necessary measure to ensure crop yield. Rational nitrogen supplementation can promote plant growth, enhance plant resistance, and achieve increased yield. However, for a long time, nitrogen fertilizer use in my country has been plagued by overuse. Coupled with the generally low nitrogen use efficiency (NUE) of grain crops in my country, the nitrogen fertilizer applied during cultivation cannot be effectively absorbed and utilized by crops. The residual nitrogen fertilizer not only wastes resources but also leads to ecological pollution, including soil compaction, acidification and secondary salinization, eutrophication of water bodies, air pollution, and excessive nitrate content in some crops. This increases environmental and food safety pressures, presenting my country with the dual challenge of mitigating nitrogen fertilizer pollution and ensuring the growth of crop yields. Therefore, improving crop nitrogen efficiency (NUE) and breeding nitrogen-efficient varieties are beneficial to solving the problem of nitrogen fertilizer overuse. While ensuring crop yield, it can reduce the amount of nitrogen fertilizer used in the production process, improve fertilizer efficiency, and reduce nitrogen fertilizer pollution to the environment.

[0003] As one of the four staple foods, rice yield and quality are closely related to my country's food security. Because rice roots secrete oxygen, their rhizosphere is in a certain oxidative state, which precisely meets the needs of nitrifying microorganisms. These nitrifying bacteria can provide rice with a large amount of nitrate nitrogen (NO3) through the root system. - Nitrate (NO3) is an important nitrogen source for rice, making it one of the most important sources of nitrogen. Therefore, enhancing the control of nitrate (NO3) is crucial. - The utilization capacity of nitrate transport proteins provides an effective solution for improving rice NUE, and nitrate transport proteins play a key role in this process.

[0004] Indica and japonica rice are two major subgroups of cultivated rice in Asia. Studies have shown that the nitrogen use efficiency (NUE) of indica rice is significantly higher than that of japonica rice. Although several genes regulating the differences in nitrogen use efficiency between indica and japonica rice have been cloned, the molecular mechanisms underlying these differences have not been fully elucidated. Exploring the molecular basis of the NUE differences between indica and japonica rice will help to comprehensively understand the regulatory mechanisms of rice NUE, discover nitrogen-efficient genes, promote their application, and facilitate the breeding of nitrogen-efficient rice varieties. The nitrate transporter OsNPF7.2 gene participates in plant nitrogen metabolism and regulates nitrogen absorption and utilization, making it a key factor contributing to differences in plant NUE. However, current research lacks assessment and practical application of nitrogen fertilizer use differences among different haplotypes of OsNPF7.2. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an application and method for improving the yield of japonica rice using the indica-type OsNPF7.2 gene and its encoded protein, thereby obtaining japonica rice overexpressing the indica-type OsNPF7.2 gene and near-isogenic lines of japonica rice possessing the indica-type OsNPF7.2 gene. To achieve the above objective, the technical solution adopted by the present invention is as follows:

[0006] An application of an indica rice type OsNPF7.2 gene and its encoded protein in increasing japonica rice yield. The nucleotide sequence of the indica rice type OsNPF7.2 gene is shown in SEQ ID NO:2, which enables the overexpression of the indica rice type OsNPF7.2 gene in rice.

[0007] Preferably, the overexpression of the OsNPF7.2 gene of indica rice in rice includes the following steps:

[0008] a. Construct an overexpression vector for the OsNPF7.2 gene of indica rice driven by its own promoter.

[0009] b. Transform the overexpression vector into intermediate bacteria to obtain positive transformants.

[0010] c. High-yielding japonica rice was obtained by infecting it with positive transformants and screening.

[0011] Preferably, the nucleotide sequence of the promoter is shown in SEQ ID NO:4.

[0012] Preferably, the amino acid sequence of the OsNPF7.2 gene of indica rice is shown in SEQ ID NO:3.

[0013] Preferably, the overexpression vector comprises an OsNPF7.2 overexpression vector of rice type driven by the OsNPF7.2 self-promoter.

[0014] pCAMBIA2300-OsNPF7.2pro-OsNPF7.2indica -ocs.

[0015] Preferably, the method for constructing the overexpression vector includes:

[0016] The OsNPF7.2 gene of indica rice was ligated into the intermediate vector pCAMBIA2300-ocs plasmid, and the resulting intermediate vector was then ligated into the final vector plasmid. The overexpression vector was obtained by driving the OsNPF7.2 gene with its own promoter.

[0017] Preferably, the amplification primers for the indica rice type OsNPF7.2 gene include:

[0018] NPF7.2cds-F:

[0019] 5'-GTATATCGTCGGATCCATGGACGCCGGAGACGCCAT-3'

[0020] NPF7.2cds-R:

[0021] 5'-ATGCCTGCAGGTCGACTCACGAGAGCACGGTCTTGA-3'

[0022] Preferably, the OsNPF7.2 promoter comprises the nucleotide sequence shown in SEQ ID NO:4.

[0023] Preferably, the amplification primers for the OsNPF7.2 promoter include:

[0024] NPF7.2pro-F:

[0025] 5'-ACGAATTCGAGCTCGGTACCTAACTTACTCTGCTTTATAT-3'

[0026] NPF7.2pro-R:

[0027] 5'-CGACTCTAGAGGATCCGACGATATACGAAATTCGCC-3'

[0028] A method for improving the yield of japonica rice by using the indica rice type OsNPF7.2 gene and its encoded protein, characterized in that the indica rice type OsNPF7.2 gene is introduced into japonica rice through hybridization to obtain a near-isogenic line containing the indica rice type OsNPF7.2 gene.

[0029] Preferably, the nucleotide sequence of the Japonica rice type OsNPF7.2 gene is shown in SEQ ID NO:1.

[0030] Preferably, the step of introducing the indica rice type OsNPF7.2 gene into japonica rice through hybridization to obtain a near-isogenic line containing the indica rice type OsNPF7.2 gene includes the following steps:

[0031] a. By crossing the donor parent indica rice with the recipient parent japonica rice, a hybrid japonica rice variety with the indica rice type OsNPF7.2 gene was obtained;

[0032] b. Perform n-generation backcrosses between the japonica rice hybrid variety and the recipient parent japonica rice, where n is an integer greater than zero, to obtain a near-isogenic line containing the indica type OsNPF7.2 gene.

[0033] Preferably, the hybridization process includes the offspring obtained by hybridizing the donor parent and the recipient parent, and backcrossing them with the recipient parent until a near-isogenic line of japonica rice with a single fragment of indica rice DNA infiltrated near OsNPF7.2 is obtained.

[0034] Preferably, the donor parent used in the hybridization is indica rice, the indica rice variety is 9311, and the recipient parent is japonica rice, the japonica rice variety is Nipponbare and Shusui 134.

[0035] Compared with existing technologies, the beneficial effects of this invention are that it has been discovered that the OsNPF7.2 gene exhibits differentiation in rice, with the indica type OsNPF7.2 gene being significantly superior to the japonica type OsNPF7.2 gene, effectively improving nitrogen-efficient fertilizer (NUE) and yield. This invention utilizes the advantages of the indica type OsNPF7.2 gene by introducing it into japonica rice varieties, obtaining near-isogenic lines of japonica rice containing the indica type OsNPF7.2 gene. Experiments have demonstrated that the production performance of these near-isogenic lines is superior to that of wild-type japonica rice. This indicates that the technical solution provided by this method reveals that the OsNPF7.2 gene is the cause of the difference in NUE and yield between japonica and indica rice. The advantages of the indica type OsNPF7.2 gene can be utilized to increase the yield of japonica rice, obtaining nitrogen-efficient japonica rice varieties, reducing nitrogen fertilizer waste and related ecological problems during production, and possessing significant economic value and application prospects. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] In the attached image:

[0039] Figure 1These are the main agronomic traits of OsNPF7.2 overexpression lines in indica and japonica rice. (a) shows the expression level of OsNPF7.2 in the overexpression lines (n=3), (b) shows the field phenotype of the overexpression lines (scale bar: 20cm), (c) shows the number of effective tillers (n≥19), (d) shows the number of grains per panicle (n≥13), and (e) shows the yield per plant (n≥13). Different letters indicate significant differences between the two groups (P<0.05, one-way ANOVA).

[0040] Figure 2 These are the main agronomic traits observed in the field of Nipponbare and NIL isotypes. (a) shows the field phenotypes of NP and NIL, with a scale bar of 20 cm; (b) shows the number of effective tillers (n = 37); (c) shows the thousand-grain weight (n = 20); (d) shows the number of grains per ear (n = 19); (e) shows the yield per plant (n ≥ 18); and (f) shows the yield per plot (n = 7). The t-test was used to analyze significant differences.

[0041] Figure 3 These are the main agronomic traits of Xiushui 134 and its near-isogenic lines in the field. (a) shows the field phenotype of Xiushui 134 and NIL, with a scale bar of 20 cm; (b) shows the yield per plant of Xiushui 134 and NIL, with a scale bar of 10 cm; (c) shows the number of effective tillers (n≥45); (d) shows the number of grains per ear (n≥27); (e) shows the yield per plant (n≥25); and (f) shows the yield per plot (n≥7). The t-test was used to analyze significant differences. Detailed Implementation

[0042] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the invention. Modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and substance of the invention are all within the scope of protection of the present invention. Unless otherwise specified, the experimental materials, reagents, instruments, etc., used in the embodiments of the present invention are all commercially available; unless specifically specified, all technical means in the embodiments of the present invention are conventional means well known to those skilled in the art.

[0043] This protocol utilizes the CRIPSR-Cas9 gene editing system to obtain the OsNPF7.2 deletion mutant rice (OsNPF7.2-1). OsNPF7.2 overexpression vectors of ZH11 and 9311 were constructed, and overexpression lines of OsNPF7.2 in japonica rice (Jap-OE) and indica rice (Ind-OE) were obtained via Agrobacterium-mediated transformation. Figure 1 ab). At maturity, the main agronomic traits of the two overexpression lines were statistically analyzed in the field. The results showed that the number of tillers and yield per plant of Ind-OE were higher than those of Jap-OE (jap. 1). Figure 1The results indicate that the OsNPF7.2 gene in indica rice is the key factor causing the yield difference between japonica and indica rice, and that the OsNPF7.2 gene in indica rice is a more efficient nitrogen-utilizing gene.

[0044] Using Nipponbare (NP) and Xiushui 134 as recipient parents and Indica 9311 as donor parents, the offspring of crosses between the donor and recipient parents were backcrossed multiple times to obtain near-isogenic lines (NILs) of Japonica rice containing the Indica type OsNPF7.2 gene. The main agronomic traits of the near-isogenic lines and their corresponding recipient parents were analyzed at maturity. The results showed that the near-isogenic lines had higher yields than the recipient parents. Figure 2 , Figure 3 This indicates that OsNPF7.2, a type of indica rice, can increase the yield of japonica rice and obtain high-yielding japonica rice varieties.

[0045] Example 1 verifies that OsNPF7.2 exhibits differentiation between japonica and indica rice types.

[0046] (1) Constructing the OsNPF7.2 deletion mutant

[0047] The knockout target was designed in the OsNPF7.2 coding region using the CRISPR-GE website (http: / / skl.scau.edu.cn / ). The sequence is as follows:

[0048] 5'-CGTCCTCCATGGCAGCAACC-3'

[0049] The sgRNA primer pair OsNPF7.2-U3-T1 was designed to target this knockout site, with the following sequence:

[0050] OsNPF7.2-U3-T1-F: 5'-GGCACGTCCTCCATGGCAGCAACC-3'

[0051] OsNPF7.2-U3-T1-R: 5'-AAACGGTTGCTGCCATGGAGGACG-3'

[0052] The primer pair OsNPF7.2-U3-T1 was denatured and annealed to obtain the primer dimer OsNPF7.2-U3-F / -R, which was then ligated into the BsaI-digested pYLsgRNA-U3 vector to obtain the intermediate vector. Subsequently, the intermediate vector was ligated into the BsaI-digested final vector pYLCRISPR / Cas9-MH using a digest-and-ligate method to obtain the OsNPF7.2 knockout vector.

[0053] The knockout vector was transformed into Agrobacterium EHA105 and then into wild-type japonica rice (ZH11) via Agrobacterium-mediated transformation. T0 generation positive seedlings were obtained through tissue culture. DNA was extracted from the positive seedlings and used as a template for PCR amplification of the NPF7.2-KO-F / R fragment using primers. Sequencing results showed that OsNPF7.2 deleter rice was obtained. Homozygous lines of the deleter (n is an integer greater than 0) were obtained through n self-crosses in the T0 generation and named OsNPF7.2-1.

[0054] The primer sequences involved are as follows:

[0055] NPF7.2-KO-F:5'-TCCTCACCCGACAATCACAA-3'

[0056] NPF7.2-KO-R:5'-GAACGTGACCAGCATCATCC-3'

[0057] (2) Construction of overexpression vectors

[0058] Using wild-type rice (ZH11) genomic DNA as a template, primer pairs were used...

[0059] The OsNPF7.2 promoter (SEQ ID NO:4) was amplified using NPF7.2pro. The pCAMBIA2300-ocs vector was digested with KpnI and BamHI, and the vector backbone was recovered. The amplified OsNPF7.2 promoter was ligated into the digested pCAMBIA2300-ocs vector using homologous recombination. The vector was sequenced to verify the results, yielding the intermediate vector pCAMBIA2300-NPF7.2promoter-ocs.

[0060] Using ZH11 cDNA as a template, NPF7.2cds was amplified using primer pair to obtain

[0061] The OsNPF7.2 coding region fragment (SEQ ID NO:1), i.e., the Japonica rice type OsNPF7.2 gene, was obtained by amplifying the OsNPF7.2 coding region fragment (SEQ ID NO:2), i.e., the Indica rice type OsNPF7.2 gene, using 9311 cDNA as a template and primer pair NPF7.2cds.

[0062] Binary vectors driving the expression of OsNPF7.2 in japonica and indica rice, respectively, were constructed. Overexpression lines were created by transforming these vectors into the osnpf7.2-1 mutant. Two types of transgenic lines with relatively consistent expression levels were then screened in the progeny of these transgenic lines. Figure 1 a) Among them, the Jap rice type OsNPF7.2 overexpression line was named Jap-OE, and the Indica rice type overexpression line was named Ind-OE.

[0063] The intermediate vector pCAMBIA2300-NPF7.2promoter-ocs was verified to be correct using BamHI and SalI double digestion and sequencing. The amplified OsNPF7.2 genes of japonica and indica rice were then ligated into the intermediate vector, respectively. Enzyme digestion of the vectors was performed for verification, yielding the overexpression vector pCAMBIA2300-OsNPF7.2pro-OsNPF7.2 of japonica rice driven by its own promoter. japonica -ocs and OsNPF7.2 self-promoter driven rice-type OsNPF7.2 overexpression vector

[0064] pCAMBIA2300-OsNPF7.2pro-OsNPF7.2 indica -ocs.

[0065] The primer sequences involved are as follows:

[0066]

[0067] (3) Construction of overexpression lines

[0068] The overexpression vectors were transformed into Agrobacterium EHA105, and the vectors were transformed into OsNPF7.2-1 obtained in (1) by Agrobacterium-mediated transformation. T0 generation positive seedlings were obtained by tissue culture. The DNA of the positive seedlings was extracted and PCR amplification of NPTII was performed using primers with the DNA as a template. Positive strains were screened to obtain overexpression lines of japonica rice type OsNPF7.2 and overexpression lines of indica rice type OsNPF7.2. The nth generation of self-crossing was performed to obtain homozygous overexpression lines (n is an integer greater than 0).

[0069] The expression level of OsNPF7.2 in homozygous overexpression lines was identified using real-time quantitative PCR. RNA was extracted from the overexpression lines and cDNA was obtained by reverse mixing. The expression level of OsNPF7.2 in the overexpression lines was detected using primer pair qOsNPF7.2, with Ubiquitin 1 as the internal control gene and primer pair qUBQ. A group of overexpression lines with relatively consistent expression levels in indica and japonica rice were identified. Figure 1 a) The indica rice overexpression line was named Ind-OE, and the japonica rice overexpression line was named Jap-OE.

[0070] The primer sequences involved are as follows:

[0071]

[0072] (4) Field survey of major agronomic traits

[0073] Overexpressing plants and deletion mutants of japonica and indica rice were planted in experimental fields under conditions that met the natural growth requirements of rice. At rice maturity, the main agronomic traits of the three materials, including effective tillering, number of grains per panicle, and yield per plant, were statistically analyzed. Figure 1 As shown, the results indicated that, during the rice maturity period, a survey of the main agronomic traits of osnpf7.2-1, Jap-OE, and Ind-OE revealed that the OsNPF7.2-indica overexpression line had significantly more effective tillers in the field than the OsNPF7.2-japonica overexpression line. Figure 1 (b, c) There was no significant difference in the number of grains per ear between the two types of transgenic lines. Figure 1 d), the yield per plant of the OsNPF7.2-indica overexpression line was significantly higher than that of the OsNPF7.2-japonica overexpression line. Figure 1 e). This indicates that OsNPF7.2-indica has a significantly stronger promoting effect on rice tillering and yield than OsNPF7.2-japonica.

[0074] Example 2: OsNPF7.2 in indica rice can increase the yield of japonica rice.

[0075] (1) Constructing a near-isogenic (NIL) line of indica rice with the OsNPF7.2 genotype.

[0076] Primer pair NPF7.2-Intron1 was used to differentiate between indica and japonica rice types OsNPF7.2.

[0077] Using Nipponbare (japonica type OsNFP7.2) as the recipient parent and 9311 (indica type OsNPF7.2) as the donor parent, pollen from the donor parent was applied to the pistils of the recipient parent during the flowering and pollination period for hybridization. The resulting offspring were repeatedly backcrossed with the recipient parent until a near-isogenic line of Nipponbare with a single fragment of 9311 DNA infiltrated near OsNPF7.2 was obtained. DNA was extracted from the near-isogenic line, and the 9311 genomic fragment in the near-isogenic line was amplified using primer pairs 2-28.11, 2-28.55, 2-29.88, and 2-29.01. Sequencing verification and screening yielded a near-isogenic line of Nipponbare with a single fragment of 9311 DNA infiltrated near OsNPF7.2.

[0078] Using Xiushui 134 (japonica type OsNFP7.2) as the recipient parent and 9311 (indica type OsNPF7.2) as the donor parent, pollen from the donor parent was applied to the pistils of the recipient parent during the flowering and pollination period for hybridization. The resulting offspring were repeatedly backcrossed with the recipient parent until a near-isogenic line of Xiushui 134 with a single fragment of 9311 DNA infiltrated near OsNPF7.2 was obtained. DNA was extracted from the near-isogenic line, and the 9311 genomic fragment in the near-isogenic line was amplified using primer pairs 2-26.43, 2-26.53, 2-26.42, and 2-29.50. Sequencing verification and screening yielded a near-isogenic line of Xiushui 134 with a single fragment of approximately 3M 9311 DNA infiltrated near OsNPF7.2.

[0079] The primer sequences involved are as follows:

[0080]

[0081]

[0082] (2) Field survey of major agronomic traits

[0083] Nearly isogenic lines of both rice varieties and their corresponding recipient parents were planted in experimental fields under conditions that met the natural growth requirements of rice. At rice maturity, the main agronomic traits of the four materials were statistically analyzed, including effective tillering, number of grains per panicle, thousand-grain weight, and yield per plant. Furthermore, the planting plots for the near isogenic lines were set as follows: each plot of Nipponbare and its near isogenic lines contained 54 individual plants, and each plot of Xiushui 134 and its near isogenic lines contained 60 individual plants. Yields were then statistically analyzed in each plot. Figure 2 As shown, the results indicate that NIL represents a near-isogenic line of Nipponbare, while NP represents the wild-type Nipponbare. The number of effective tillers, grains per ear, and yield per plant and plot were significantly higher in NIL than in NP. Figure 3 As shown, NIL represents the near-isogenic line of Xiushui 134, and XS represents the wild-type Xiushui 134. The effective tiller number, single plant yield, and plot yield of NIL are significantly higher than those of XS. This indicates that the production performance of the near-isogenic line of japonica rice containing the indica type OsNPF7.2 gene is superior to that of wild-type japonica rice.

[0084] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. The application of an indica rice type OsNPF7.2 gene and its encoded protein in increasing japonica rice yield, characterized in that, The nucleotide sequence of the indica rice type OsNPF7.2 gene is shown in SEQ ID NO:2, enabling overexpression of the indica rice type OsNPF7.2 gene in rice.

2. The application as described in claim 1, characterized in that, The method for overexpressing the OsNPF7.2 gene of indica rice in rice includes the following steps: a. Construct an overexpression vector for the OsNPF7.2 gene of indica rice driven by its own promoter; b. Transform the overexpression vector into intermediate bacteria to obtain positive transformants; c. High-yielding japonica rice was obtained by infecting it with positive transformants and screening.

3. The application as described in claim 2, wherein the nucleotide sequence of the promoter is shown in SEQ ID NO:

4.

4. The application as described in claim 2, wherein the amino acid sequence of the indica rice type OsNPF7.2 gene is shown in SEQ ID NO:

3.

5. The application according to claim 2, characterized in that, The method for constructing the overexpression vector includes: The OsNPF7.2 gene of indica rice was ligated into the intermediate vector pCAMBIA2300-ocs plasmid, and the resulting intermediate vector was then ligated into the final vector plasmid. The overexpression vector was obtained by driving the OsNPF7.2 gene with its own promoter.

6. A method for improving the yield of japonica rice using the OsNPF7.2 gene of indica rice and its encoded protein, characterized in that... By introducing the OsNPF7.2 gene from indica rice into japonica rice through hybridization, near-isogenic lines containing the OsNPF7.2 gene from indica rice were obtained.

7. The method according to claim 6, characterized in that, The nucleotide sequence of the OsNPF7.2 gene of japonica rice is shown in SEQ ID NO:

1.

8. The method according to claim 6, characterized in that, The method of introducing the indica rice type OsNPF7.2 gene into japonica rice through hybridization to obtain a near-isogenic line containing the indica rice type OsNPF7.2 gene includes the following steps: a. By crossing the donor parent indica rice with the recipient parent japonica rice, a hybrid japonica rice variety with the indica rice type OsNPF7.2 gene was obtained; b. Perform n-generation backcrosses between the japonica rice hybrid variety and the recipient parent japonica rice, where n is an integer greater than zero, to obtain a near-isogenic line containing the indica type OsNPF7.2 gene.

9. The method according to claim 8, characterized in that, The hybridization process involves crossing the donor parent and the recipient parent to obtain offspring, which are then backcrossed with the recipient parent until a near-isogenic line of japonica rice with a single fragment of indica rice DNA infiltrated near OsNPF7.2 is obtained.

10. The method according to claim 8, characterized in that, The donor parent used in the hybridization was indica rice, variety 9311, and the recipient parent was japonica rice, varieties Nipponbare and Shusui 134.

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