Use of Arabidopsis thaliana AteIF4E gene in improving plant nitrogen use efficiency and yield

Abstract

The present invention discloses the use of the Arabidopsis thaliana AteIF4E gene in improving plant nitrogen use efficiency and yield, belonging to the technical field of plant genetic engineering. The present invention discovers a new gene AteIF4E involved in NO3 ‑ signal regulation, and studies its function in improving plant nitrogen use efficiency and yield. This gene can participate in the regulation of plant NO3 ‑ signaling and absorption. Overexpression of AteIF4E can promote plant growth and improve plant nitrogen use efficiency and yield. The present invention improves the gene network for regulating nitrogen, clarifies the function of AteIF4E in improving plant nitrogen use efficiency and yield, and provides new ideas and directions for the subsequent cultivation of new high-nitrogen-efficient crop varieties.

Description

Technical Field

[0001] The present invention relates to the technical field of plant genetic engineering, and particularly relates to the use of Arabidopsis AteIF4E gene in improving plant nitrogen use efficiency and yield. Background Art

[0002] In agricultural production, due to the low nitrogen absorption and utilization rate of crop varieties, a considerable part of the applied nitrogen fertilizer is lost to the environment, causing very serious ecological and environmental problems, such as: eutrophication of surface water, soil acidification, etc. (Conley et al., 2009; Guo et al., 2010). Improving the nitrogen use efficiency of crops is the key to solving these problems. However, at present, we still do not clearly understand the laws and mechanisms of plant regulation of nitrogen absorption and utilization, resulting in very limited progress in improving the nitrogen use efficiency of crops. Therefore, it is urgent to strengthen the research on the excavation and utilization of nitrogen regulation genes to analyze and improve the gene network regulating nitrogen, clarify the laws and mechanisms of plant absorption and utilization of nitrogen, which is of great significance for achieving high yield and high efficiency of crops.

[0003] Most terrestrial plants (such as wheat, corn, etc.) mainly absorb nitrate nitrogen (NO 3 - ) from the soil. NO 3 - is not only a nutrient but also a signal molecule. When the plant root senses NO outside the root 3 - , it will induce the expression of NO 3 - response genes and affect the absorption and utilization of NO 3 - , thereby regulating the growth of plants. The response of plants to NO 3 - is divided into two types: short-term effect and long-term effect. The short-term effect refers to the primary response of NO 3 - , that is, after NO 3 - treatment, some genes (genes of the NRT family, NIA, NiR, etc.) are induced to express in a short time (Wang et al., 2000; Scheible et al., 2004). The long-term effect refers to the effects on the growth and development of plant roots, flowering, seed germination, etc. after a long time of NO 3 - treatment (Alboresi et al., 2005; Walch-Liu et al., 2006; Marín et al., 2011).

[0004] Previously, people's understanding of NO3 - The research mainly focuses on the identification of genes involved in NO 3 - transport and assimilation. Since 2009, with the application of a variety of new technologies and methods in plant research, some new genes regulating the short-term response of plant NO 3 - have been successively discovered. 1) NRT1.1 is a regulatory gene screened by forward genetics and is also the first discovered NO 3 - sensor protein, which plays a very important role in NO 3 - signal regulation, and this role does not depend on its transport activity (Ho et al., 2009; Wang et al., 2009); in rice, OsNRT1.1B can interact with SPX4 to participate in the regulation of NO 3 - signals (Hu et al., 2019); CIPK23 can phosphorylate NRT1.1, thereby affecting the regulation of NRT1.1 on the primary response of NO 3 - (Ho et al., 2009); the expression level of CIPK8 is significantly decreased in the nrt1.1 mutant and positively regulates the primary response of NO 3 - under high-concentration NO conditions (Hu et al., 2009); in addition, through forward genetics, NGR2 and CPSF30-L have also been screened. Both of these two genes act upstream of NRT1.1 in the NO 3 - signal pathway and regulate the expression of NRT1.1. NRG2 can interact with NLP7 (Xu et al., 2016); CPSF30-L affects the alternative splicing of the 3' UTR of NRT1.1 mRNA and plays an important regulatory role at the post-transcriptional level (Li et al., 2017); further research found that the recognition of m6A methylation modification mediated by CPSF30-L affects plant nitrogen signaling and metabolism by regulating the alternative polyadenylation (APA) of downstream target genes (Hou et al., 2021). 2) The transcription factors NLP7 and LBD37 / 38 / 39 have been identified by reverse genetics. NLP7 plays an important role in regulating the NO 3 - response (Castaings et al., 2009). Further research found that NLP6 / 7 can bind to NO 3 - response. Further research found that NLP6 / 7 can bind to NO 3 -Response element NRE, regulating genes involved in NO 3 - signaling and metabolism (Konishi and Yanagisawa, 2013; Marchive et al., 2013); CPK10 / 30 / 32 is involved in NO 3 - signaling regulation through phosphorylation of NLP7 (Liu et al., 2017); NIGT1 acts downstream of NLP7 and inhibits the expression of NRT2.1 by directly binding to its promoter (Maeda et al., 2018). LBD37 / 38 / 39 can inhibit the expression of NO 3 - responsive genes as well as absorption and assimilation genes (Scheible et al., 2004; Rubio et al., 2009). 3) SPL9, bZIP1, and TGA1 / 4 are NO 3 - regulatory genes identified by systems biology. SPL9 can target NO 3 - primary response genes and negatively regulate NO 3 - signaling (Krouk et al., 2010); bZIP1 can catalyze the rapid and extensive response of plants at the transcriptional level to external NO 3 - changes (Doidy et al., 2016); while TGA1 / 4 regulates the expression of NRT2.1 and NRT2.2 by binding to their promoters (Alvarez et al., 2014).

[0005] Eukaryotic translation initiation factor 4E (eIF4E) belongs to the recessive disease resistance genes of plants. Members of the plant eIF4E gene family include eIF4E and its isoform eIFiso4E. Both eIF4E and eIFiso4E proteins are present in the plant cytoplasm, have certain functional redundancy, show sensitivity to virus infection, and play a key role in the process of virus infection. Different members of the eIF4E gene family mediate responses to different types of viruses, and the dependence of the same virus on members of the eIF4E gene family may also be different in different plants. However, there is currently no report on the AteIF4E gene from Arabidopsis thaliana in improving plant nitrogen use efficiency and yield. Summary of the Invention

[0006] In view of the above-mentioned prior art, the object of the present invention is to provide the use of Arabidopsis AteIF4E gene in improving plant nitrogen use efficiency and yield. Through the study of mutants of the AteIF4E gene, the present invention finds that AteIF4E is involved in NO 3 - signal regulation and affects the absorption of NO 3 - by plants; overexpression of AteIF4E can promote plant growth and improve plant nitrogen use efficiency (NUE) and yield.

[0007] In the first aspect of the present invention, there is provided the use of Arabidopsis AteIF4E gene in at least one of the following (1)-(3):

[0008] (1) Affecting the expression of NO 3 - responsive genes in plants;

[0009] (2) Improving the nitrogen use efficiency of plants;

[0010] (3) Improving plant yield;

[0011] The Arabidopsis AteIF4E gene is a nucleic acid molecule as shown in the following i)-iii):

[0012] i) A nucleic acid molecule whose nucleotide sequence is the nucleic acid molecule shown in SEQ ID NO.1;

[0013] ii) A nucleic acid molecule encoding the amino acid sequence shown in SEQ ID NO.2 other than i);

[0014] iii) A DNA fragment having 90% or more identity with the DNA fragment defined in i) or ii) and encoding a protein functionally equivalent to the protein shown in SEQ ID NO.2.

[0015] In the above application, the NO 3 - responsive genes include: NIA1 gene, NiR gene and NRT2.1 gene.

[0016] In the above application, the Arabidopsis AteIF4E gene improves the nitrogen use efficiency of plants and increases the yield by promoting the absorption of NO 3 - by plants.

[0017] In the second aspect of the present invention, there is provided the use of the protein encoded by Arabidopsis AteIF4E gene in (1) or (2) below:

[0018] (1) Improving the nitrogen use efficiency of plants;

[0019] (2) Improve plant yield.

[0020] In the above application, the amino acid sequence of the protein encoded by the Arabidopsis thaliana AteIF4E gene is as shown in SEQ ID NO.2.

[0021] In the third aspect of the present invention, there is provided the use of a recombinant expression vector, a transgenic cell line or an engineered bacterium containing the Arabidopsis thaliana AteIF4E gene in any one of the following (1)-(3):

[0022] (1) Improve the nitrogen use efficiency of plants;

[0023] (2) Improve plant yield;

[0024] (3) Breed high-nitrogen-efficient crop varieties.

[0025] In the above application, the recombinant expression vector can be constructed using, but not limited to, existing plant expression vectors. For example, pPZP211, pCAMBIA1300, pBI121, pBin19, pCAMBIA2301, pCAMBIA1301-UbiN or other derivative plant expression vectors.

[0026] The host cell of the engineered bacterium can be Escherichia coli, Agrobacterium, etc.

[0027] In the fourth aspect of the present invention, there is provided a method for improving the nitrogen utilization rate of plants, including: the step of overexpressing the eIF4E gene in plants.

[0028] In the above method, overexpressing the eIF4E gene in plants can be achieved by the method of exogenous transfer of the AteIF4E gene; or upregulating the expression of the AteIF4E gene or its homologous gene in the plant genome.

[0029] In the fifth aspect of the present invention, there is provided a method for breeding high-nitrogen-efficient crop varieties, including the following steps:

[0030] Transfer the AteIF4E gene into the starting plant to obtain a high-nitrogen-efficient crop;

[0031] Or upregulate the expression of the AteIF4E gene or its homologous gene in the genome of the starting plant, and screen for plants with improved nitrogen utilization rate and yield.

[0032] Preferably, the method for transferring the AteIF4E gene into the starting plant includes: polyethylene glycol method, Agrobacterium-mediated method or gene gun bombardment method.

[0033] Advantages of the present invention:

[0034] The present invention discovers a new one involved in NO 3- The signal-regulated gene AteIF4E was studied for its function in improving plant nitrogen use efficiency and yield. This gene can participate in the regulation of NO 3 - signaling and uptake. Overexpression of AteIF4E can promote plant growth and improve plant nitrogen use efficiency and yield. The present invention improves the gene network for regulating nitrogen, clarifies the function of AteIF4E in improving plant nitrogen use efficiency and yield, and provides new ideas and directions for the later cultivation of new high-nitrogen-efficient crop varieties. Brief Description of the Drawings

[0035] Figure 1 : eIF4E affects the expression of plant NO 3 - responsive genes. After WT, eif4e-1, eif4e-2, and eif4e-4 seeds were grown in 2.5 mM NH 4 -Suc liquid medium for 7 days, they were treated with 5 mM KNO 3 (+N) and 5 mM KCl (-N, as a control) for 2 hours, and then roots were taken and RNA was extracted for qPCR detection. Among them, WT: wild type; eif4e-1, eif4e-2, and eif4e-4: three different eIF4E gene mutants.

[0036] Figure 2 : eIF4E affects the uptake of NO 3 - by plants. Figure 2 A: Detection of 15 N uptake in plants. After WT, eif4e-1, eif4e-2, and eif4e-4 seeds were grown in 5 mM NH 4 NO 3 liquid medium for 9 days, the 5 mM NH 4 NO 3 liquid medium was replaced on the evening of the 9th day and the morning of the 10th day, respectively. After 3 h, 5 mL of 10 mM NH 4 15 NO 3 was added for treatment for 30 min, and then it was washed with 0.1 mM CaSO 4 for 1 min. The whole seedlings were taken, dried, ground, and used for 15 N detection. Figure 2 B: NO in eif4e 3 -Detection of the expression of genes involved in NO absorption: WT, eif4e-1, eif4e-2, and eif4e-4 were grown on 1 / 2 MS medium for 7 days. Roots were then collected and RNA was extracted for qPCR analysis. WT: wild type; eif4e-1, eif4e-2, and eif4e-4: three different eIF4E gene mutants.

[0037] Figure 3 : Study on the promotion of plant growth by eIF4E overexpression lines. WT, eif4e-1, eif4e-2, eIF4E-OE-1, and eIF4E-OE-2 were vertically grown on 0.3 mM and 5 mM KNO 3 medium for 10 days to observe the phenotypes ( Figure 3 A), and the primary root length ( Figure 3 B) and fresh weight per plant ( Figure 3 C) were measured. Among them, WT: wild type; eif4e-1, eif4e-2: eIF4E gene mutants; eIF4E-OE-1, eIF4E-OE-2: two different eIF4E overexpression lines.

[0038] Figure 4 : Study on the improvement of nitrogen use efficiency by eIF4E overexpression lines. WT, eif4e-1, eif4e-2, eIF4E-OE-1, and eIF4E-OE-2 were grown in vermiculite and irrigated with 0.3 mM and 5 mM KNO 3 nutrient solution. The growth phenotypes of the plants were observed at 50 days ( Figure 4 A), and the plant height ( Figure 4 B) was measured. After the plants matured, the grain phenotypes ( Figure 4 C) were observed, and the 1000-grain weight ( Figure 4 D), yield per plant ( Figure 4 E), and NUE ( Figure 4 F) were measured. Among them, WT: wild type; eif4e-1, eif4e-2: eIF4E gene mutants; eIF4E-OE-1, eIF4E-OE-2: two different eIF4E overexpression lines. Detailed implementation methods

[0039] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0040] Term description:

[0041] NO 3 - Regulatory gene: Plays the role of NO 3 -Upstream genes with signal regulatory functions can regulate multiple NOs including responsive genes 3 - Utilize the functions of genes.

[0042] NO 3 - Responsive genes: Some relatively downstream genes that can undergo transcriptional level changes after being treated with NO 3 - Processing.

[0043] NUE: Nitrogen use efficiency, calculated as: yield / nitrogen application rate.

[0044] As mentioned above, nitrogen plays an extremely important role in plant growth and development. Exploring more nitrogen regulatory genes, enriching and improving the gene network for nitrogen regulation, analyzing the laws and mechanisms of nitrogen absorption and utilization, and cultivating new varieties of nitrogen-efficient crops are of great significance for achieving high-yield and high-efficiency agriculture.

[0045] In the prior art, plant eIF4E genes are mainly used as recessive disease-resistant genes, and there is no relevant report on the AteIF4E gene derived from Arabidopsis thaliana in improving plant nitrogen use efficiency and yield.

[0046] The inventors have been deeply involved in the field of plant NO 3 - Regulation for many years. Previously, a NO 3 - Regulatory gene mutant was screened through forward genetics, and finally the target gene AteIF4E was cloned. The nucleotide sequence of the AteIF4E gene is shown in SEQ ID NO.1, as follows:

[0047]

[0048] The amino acid sequence of the protein encoded by the AteIF4E gene is shown in SEQ ID NO.2, as follows:

[0049]

[0050] To study the functions of eIF4E in NO 3 - Signal regulation and metabolism, the inventors first examined the expression of NO 3 - Responsive genes in the eIF4E gene mutant obtained previously and found that the induced expression of NO 3 - Responsive genes in the mutant was significantly lower than that in the wild type, indicating that eIF4E is a NO 3 - Regulatory gene and can participate in NO3 - Signal regulation. Meanwhile, regarding the study on the mutants in NO 3 - absorption, it was found that in the mutants, 15 N absorption decreased, and the expression of NO 3 - transport genes decreased, indicating that eIF4E regulates the absorption of NO by plants. 3 -

[0051] On the other hand, to study the function of eIF4E in improving the nitrogen use efficiency of plants, the inventor cloned the gene fragment of eIF4E using PCR technology. Using the cDNA of 7-day-old seedlings as a template, the following primers were used for amplification:

[0052] Forward primer: 5’-GTCGACATGGCGGTAGAAGACACTCC-3’

[0053] Reverse primer: 5’-ACTAGTAGCGGTGTAAGCGTTCTTT-3’

[0054] After obtaining the above gene fragment of eIF4E, the inventor transferred it into the wild-type receptor plant Arabidopsis thaliana to obtain a transgenic line with overexpression of eIF4E. By observing the growth phenotype of the overexpression line, it was found that overexpression of eIF4E could promote plant growth, increase grain yield and nitrogen use efficiency. Based on the above results, the present invention was proposed.

[0055] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

[0056] The test materials used in the embodiments of the present invention are all conventional test materials in the art and can be obtained through commercial channels. The experimental methods without specifying detailed conditions are carried out according to conventional test methods or according to the operation manuals recommended by the suppliers.

[0057] eif4e-1, eif4e-2, and eif4e-4 are all mutants of the Arabidopsis thaliana eIF4E gene. Among them, the 297th base of eif4e-1 mutated from G to A, resulting in the 99th tryptophan becoming a stop codon; eif4e-2 is a T-DNA insertion mutant, causing gene knockout; the 407th base of eif4e-4 mutated from A to G, resulting in the 136th glycine mutating to glutamic acid.

[0058] Example 1: Expression of NO-responsive genes in eif4e mutants 3 - ​​

[0059] First, seeds of wild-type plants and eIF4E gene mutants (eif4e-1, eif4e-2, and eif4e-4) were grown in 2.5 mM NH 4 -Suc liquid medium for 7 days. Then, a certain amount of 1 M KNO 3 (+N) or KCl (-N, as a control) solution was added to the liquid medium to make the final concentration of KNO 3 or KCl in the medium 5 mM. After 2 hours, roots were taken to extract RNA, and the expression levels of NO 3 - responsive genes NIA1, NiR, and NRT2.1 were detected using qPCR technology.

[0060] The primer sequences are as follows:

[0061]

[0062] 2.5 mM NH 4 -Suc medium formula:

[0063]

[0064] The results are as Figure 1 shown. The results indicate that after NO 3 - treatment, the expression levels of NO 3 - responsive genes NIA1, NiR, and NRT2.1 were significantly decreased in the eif4e mutants, indicating that eIF4E is a NO 3 - regulatory gene and can participate in the signal regulation of NO 3 - in plants.

[0065] Example 2: Identification of the NO 3 - absorption function of mutants

[0066] First, the N absorption of eif4e mutants 15 was detected. Seeds of wild-type plants (WT) and eIF4E gene mutants (eif4e-1, eif4e-2, and eif4e-4) were grown in 5 mM NH 4 NO 3 liquid medium for 9 days. Then, the 5 mM NH 4 NO 3 liquid medium was replaced on the evening of the 9th day and the morning of the 10th day to ensure that the NH 4 NO 3The content was sufficient. 3 hours after changing the medium on the morning of the 10th day, 5 mL of 10 mM NH 4 15 NO 3 was added and the treatment lasted for 30 min, then it was washed with 0.1 mM CaSO 4 for 1 min. After drying and grinding the whole seedlings, the 15 N content in the sample was determined by a stable isotope mass spectrometer. 15 The 15 N content reflected the absorption of 15 N by the plants. It was found that the Figure 2 N absorption in the mutants was significantly lower than that in the wild type (

[0067] NH 4 NO 3 Liquid medium formula:

[0068]

[0069] Then, the expression of the genes related to NO 3 - transport was detected. WT, eif4e-1, eif4e-2, and eif4e-4 were grown on 1 / 2 MS medium for 7 days, and then the roots were taken to extract RNA. The expression of the NO 3 - transport genes NRT1.1 and NRT1.2 was detected by qPCR. It was found that the expression of the NO 3 - transport genes in the mutants was significantly lower than that in the wild type ( Figure 2 B).

[0070] The primer sequences are as follows:

[0071]

[0072] 1 / 2 MS medium formula:

[0073]

[0074] Note: After volume fixing, the pH value was adjusted to 5.7 with KOH.

[0075] The above experimental results indicate that eIF4E can affect the 3 - absorption of

[0076] Example 3: Construction of the plant expression vector of the eIF4E gene

[0077] Arabidopsis wild type was grown on 1 / 2 MS medium for 7 days. The whole seedlings were taken and RNA was extracted. The RNA was reverse transcribed into cDNA using a reverse transcription kit. Using the cDNA as a template, the gene fragment of eIF4E was amplified using a high-fidelity DNA polymerase. The primer sequences used for PCR were:

[0078] Forward primer: 5’-GTCGACATGGCGGTAGAAGACACTCC-3’

[0079] Reverse primer: 5’-ACTAGTAGCGGTGTAAGCGTTCTTT-3’

[0080] The PCR products were subjected to 1% agarose gel electrophoresis. The gel block of the target band was cut off, and the target DNA was recovered using a gel extraction kit (Omega). The recovered target DNA and the plant expression vector pPZP211 were digested with enzymes (SalI and SpeI), and then the digested DNA fragments and the vector were ligated with T 4 DNA ligase. The ligation product was transformed into Escherichia coli Mach1 competent cells by heat shock method. The cells were cultured on a shaker at 37 °C with 230 rpm for 1 hour, and then spread on an LB plate containing 50 μg / mL spectinomycin and cultured inverted at 37 °C for 12 - 15 hours. Positive clones successfully transformed with the recombinant vector were screened by colony PCR technology. The bacterial cells of the positive clones were picked and cultured in 5 mL of LB liquid culture medium containing 50 μg / mL spectinomycin, and the plasmids were extracted for sequencing. The sequencing results were compared with the sequence of eIF4E. The plasmids with correct sequencing were transformed into Agrobacterium tumefaciens GV3101 competent cells. The cells were cultured on a shaker at 30 °C with 230 rpm for 3 hours, spread on an LB plate containing 50 μg / mL spectinomycin, and cultured inverted at 30 °C for 36 hours. Agrobacterium tumefaciens successfully transformed with the recombinant plasmid was identified by colony PCR and the bacterial strain was stored at -80 °C.

[0081] LB liquid medium formula:

[0082]

[0083] Example 4: Identification of transgenic positive plants

[0084] The Agrobacterium tumefaciens cells stored at -80 °C were picked and cultured in 5 mL of LB (containing 50 μg / mL spectinomycin) medium on a shaker at 30 °C with 230 rpm for 15 hours. 1 mL of the bacterial liquid was taken and added to 200 mL of LB (containing 50 μg / mL spectinomycin) medium, and the cells were cultured on a shaker at 28 °C with shaking for 16 hours. The Agrobacterium tumefaciens was used to infect Arabidopsis wild type plants by floral dip method, and the finally harvested seeds were spread on 1 / 2 MS medium containing 50 μg / mL kanamycin for growth to screen positive seedlings, namely transgenic line T0 generation. Transplant the screened T 0 -generation seeds into vermiculite for cultivation, and harvest the T 1 -generation seeds. Sow the T 1 -generation seeds on 1 / 2 MS medium containing 50 μg / mL kanamycin. It is found that the survival rate is 3 / 4. Transplant the surviving T 1 plants into vermiculite for cultivation, and harvest the T 2 -generation seeds from each single plant. Sow the T 2 -generation seeds on 1 / 2 MS medium containing 50 μg / mL kanamycin, screen the homozygous transgenic lines and transplant them into vermiculite for propagation.

[0085] Example 5: Study on the promotion of plant growth by overexpression of eIF4E gene

[0086] Study on the promotion of plant growth by eIF4E overexpression lines. Vertically grow WT, eif4e-1, eif4e-2, and the eIF4E homozygous transgenic lines eIF4E-OE-1 and eIF4E-OE-2 screened in Example 4 on 0.3 mM and 5 mM KNO 3 medium for 10 days, observe the phenotypes ( Figure 3 A), and measure the primary root length ( Figure 3 B) and fresh weight ( Figure 3 C). The results show that overexpression of eIF4E can promote plant growth.

[0087] 0.3 mM or 5 mM KNO 3 Medium formulation:

[0088]

[0089] Example 6: Study on the improvement of plant nitrogen use efficiency by overexpression of eIF4E gene

[0090] Study on the improvement of plant yield and nitrogen use efficiency by eIF4E overexpression lines. Sow WT, eif4e-1, eif4e-2, eIF4E-OE-1, and eIF4E-OE-2 seeds in vermiculite for growth, irrigate with 0.3 mM and 5 mM KNO 3 nutrient solution according to the growth situation, and record the irrigation amount each time for later calculation of nitrogen application rate. Observe the phenotypes of the plants after 50 days of growth and measure the plant height ( Figure 4 A and 4B). After the plants are completely mature, observe the grain phenotypes ( Figure 4 C) and measure the 1000-grain weight ( Figure 4 D), yield per plant ( Figure 4 E) and NUE ( Figure 4 F). The results show that overexpression of eIF4E can improve plant yield and NUE.

[0091] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. Use of overexpressing Arabidopsis thaliana AteIF4E gene in improving plant nitrogen use efficiency; the Arabidopsis thaliana AteIF4E gene is a nucleic acid molecule as shown in the following i) or ii): i) A nucleic acid molecule with the nucleotide sequence shown in SEQ ID NO.1; ii) A nucleic acid molecule encoding the amino acid sequence shown in SEQ ID NO.2 other than i).

2. The use according to claim 1, wherein, The Arabidopsis thaliana AteIF4E gene improves the nitrogen use efficiency of plants by promoting the absorption of NO 3 - by the plant body.

3. Use of the protein encoded by the overexpressing Arabidopsis thaliana AteIF4E gene in improving plant nitrogen use efficiency; the amino acid sequence of the protein encoded by the Arabidopsis thaliana AteIF4E gene is as shown in SEQ ID NO.

2.

4. Use of a recombinant expression vector, transgenic cell line or engineered bacterium containing the Arabidopsis thaliana AteIF4E gene in the following (1) or (2): (1) Improving plant nitrogen use efficiency; (2) Cultivating high nitrogen - efficient crop varieties; The Arabidopsis thaliana AteIF4E gene is a nucleic acid molecule as shown in the following i) or ii): i) A nucleic acid molecule with the nucleotide sequence shown in SEQ ID NO.1; ii) A nucleic acid molecule encoding the amino acid sequence shown in SEQ ID NO.2 other than i).

5. A method for improving plant nitrogen utilization rate and yield, wherein, it includes: The step of overexpressing the Arabidopsis thaliana AteIF4E gene in plants; The Arabidopsis thaliana AteIF4E gene is a nucleic acid molecule as shown in the following i) or ii): i) A nucleic acid molecule with the nucleotide sequence shown in SEQ ID NO.1; ii) A nucleic acid molecule encoding the amino acid sequence shown in SEQ ID NO.2 other than i).

6. The method according to claim 5, wherein, The method for overexpressing the Arabidopsis thaliana AteIF4E gene in plants includes: exogenously transferring the Arabidopsis thaliana AteIF4E gene; or up - regulating the expression of the Arabidopsis thaliana AteIF4E gene in the plant genome.

7. A method for cultivating high nitrogen - efficient crop varieties, wherein, it includes the following steps: Transferring the AteIF4E gene into the starting plant to obtain high nitrogen - efficient crops; Or up - regulating the expression of the AteIF4E gene in the genome of the starting plant and screening for plants with improved nitrogen utilization rate and yield; The AteIF4E gene is a nucleic acid molecule as shown in the following i) or ii): i) A nucleic acid molecule with the nucleotide sequence shown in SEQ ID NO.1; ii) A nucleic acid molecule encoding the amino acid sequence shown in SEQ ID NO.2 other than i).

8. The cultivation method according to claim 7, wherein, The method for transferring the AteIF4E gene into the starting plant includes: polyethylene glycol method, Agrobacterium - mediated method or gene gun bombardment.

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