CN116751885A - Identification method and application of key genes expressed under influence of sunlight in rice - Google Patents

Abstract

The invention discloses an identification method and application of key genes expressed under the influence of sunlight in rice, which adopts rice seedlings to treat two different conditions, namely indoor (incandescent lamp) and outdoor (natural sunlight); setting different treatment time points, and sampling seedlings; transcriptome analysis is carried out on the sampled sample, and the key genes which are differentially expressed under the influence of sunlight are identified. The invention completes the functional verification of RTN1 gene, defines the feasibility of the identification method, and lays a foundation for further excavating key genes regulated and controlled by illumination, improving the plant type of crop rice and increasing the yield. Wherein the RTN1 gene (Seq ID No: 1) is expressed by sun light induction and participates in photosynthesis of rice, and the gene encodes a fructose-1, 6-bisphosphate aldolase (Seq ID No: 2). RTN1 participates in regulating and controlling the elongation of rice tillering buds, so that the tillering number and the rice yield are influenced, and a certain theoretical basis is provided for the research on the formation of the rice yield.

Description

A method and application for identification of key genes whose expression is affected by sunlight in rice

Technical field

The invention relates to the field of plant genetic engineering, and in particular to a method and application for identification of key genes expressed in rice that are affected by sunlight.

Background technique

Light is one of the most important environmental signals affecting plant growth and development. Plants have formed a variety of photoreceptor systems during their historical evolution, mainly including phytochromes, cryptochromes, phototropins, photoreceptor-like and UV-B Receptors, etc., are used to receive light signals and conduct light signals within the plant body. This system is involved in regulating the normal progress of important life activities and physiological reactions of plants such as seed germination, photomorphogenesis, flowering and fruiting, and plant senescence.

Photosynthesis refers to the biological process in which green plants absorb light energy, assimilate carbon dioxide and water, synthesize organic matter, and release oxygen. The products of photosynthesis are mainly sugars, which are used to store energy in plants. Light energy is the main energy source for plant photosynthetic reactions. However, plants absorb different amounts of solar energy of different wavelengths, resulting in different photosynthetic products. Studies have shown that under red light irradiation, leaves tend to produce abundant carbohydrates and less protein synthesis; while under blue light irradiation, carbohydrates are significantly reduced and protein content is significantly increased.

Photosynthesis is a photobiochemical reaction. Within a certain range, the photosynthetic rate increases with the increase of light intensity. However, when the light intensity exceeds a certain range, the photosynthetic rate no longer increases accordingly. This phenomenon is called light saturation. The light saturation phenomenon is mainly for C3 plants, and the light saturation point of C4 plants is much higher than that of C3 plants. Representative plants include corn and sorghum, and their biological yield is also higher than that of C3 plants. Therefore, efficient use of light energy improves photosynthetic efficiency. , increasing plant yield is an important topic in the field of food crop research.

In addition, affected by light conditions, gene expression and encoded protein molecular functions in plants must undergo significant changes. Although some functional genes have been reported to be affected by light conditions and regulate the growth and development of plants, there are currently no treatments using sunlight and incandescent lamps. Plant materials, especially for monocots, are used to identify important differentially expressed genes affected by different light and how they affect plant morphogenesis and other related research reports.

Rice is one of the most important food crops in the world, feeding nearly half of the world's population. Therefore, the level of rice production is crucial to food security, and the sustained and stable growth of rice production is the basis of food security. Plant type is an important agronomic trait that affects yield, so breeding rice with ideal plant type is an important way to solve rice yield problems. Plant type generally refers to the morphological characteristics of its above-ground tissues and their spatial arrangement. Different plant types have a greater impact on the plant's viability, yield, and ability to adapt to the environment. Rice plant type mainly depends on the number and angle of tillers, plant height, leaf shape and panicle morphology. Among them, tillers are an important indicator for determining rice plant type. The number of tillers will directly affect the effective number of panicles of rice, thereby affecting the final yield of rice.

It can be seen that the identification method of key genes regulated by light still needs to be further developed. How to create a new identification method and application of key genes expressed by sunlight in rice, so that it can unearth more genes affected by sunlight. Sunlight affects the expression of key genes, which lays the foundation for improving the plant shape of rice crops and increasing yields. It has become a target that needs improvement in the current industry.

Contents of the invention

The technical problem to be solved by the present invention is to provide a brand-new identification method and application of key genes expressed by sunlight in rice, so that more key genes expressed by sunlight can be excavated and provide a basis for improving crop rice strains. model and increase production.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

On the one hand, the present invention provides a method for identifying key genes expressed in rice that are affected by sunlight, including the following steps:

(1) Rice seedlings are treated under two different conditions, indoors and outdoors, where the indoor lighting method is incandescent lamps and the outdoor lighting method is natural sunlight;

(2) Set different treatment time points to sample seedlings;

(3) Conduct transcriptome analysis on the sampled samples to identify key genes differentially expressed by sunlight.

As a further improvement of the present invention, in step (1), the light intensity and relative wavelength of two different conditions, indoor and outdoor, show significant differences; wherein, the relative spectral value coverage of outdoor sunlight in the relative wavelength range is significantly high. Compared with indoor incandescent lamp conditions; outdoor light intensity at the three light intensity detection time points of 9:00, 11:00 and 17:00 is also significantly higher than indoor incandescent lamp conditions.

In the step (1), the rice seedlings are rice seedlings grown indoors for 21 days, and the germinated seeds are sown into boxes containing field soil, and placed in indoor incandescent lamp treatment conditions to grow for 21 days.

In the step (1):

Setting of indoor conditions: incandescent lighting time, 5:00 am to 19:00 pm; dark time, 19:00 pm to 5:00 am the next day;

Setting of outdoor conditions: natural sunlight lighting time, 5:00 am to 19:00 pm; dark time, 19:00 pm to 5:00 am the next day.

In the step (2), the treatment time points of 0 days, 3 days, 7 days and 15 days or the treatment time points of 3 days, 7 days and 15 days are set, and the stem base tissues of the indoor and outdoor treated rice seedlings are sampled respectively. .

After the transcriptome analysis and identification of differentially expressed key genes in step (3), metabolic pathway analysis is performed, and the functional verification of the differentially expressed genes involved in photosynthesis is performed.

On the other hand, the present invention also provides an application of key genes whose expression is affected by sunlight in rice. The key genes participate in rice photosynthesis and are used to control rice growth and development and rice plant type.

The key gene is the gene RTN1 encoding fructose-1,6-bisphosphate aldolase. The sequence of the RTN1 gene is shown in Seq ID No: 1. The protein sequence of the RTN1 gene is shown in Seq ID No: 2. , the gene is used for positive regulation:

(1) Elongation of rice tiller buds;

(2) Number of rice tillers;

and/or (3) rice yield.

On the other hand, the present invention also provides a mutant gene of a key gene whose expression is affected by sunlight in rice. The mutant gene has an insertion of a base C at position 154 of the sequence shown in Seq ID No: 1. Mutated sequence, or a sequence in which one base C is deleted at position 154 of the sequence shown in Seq ID No: 1.

On the other hand, the present invention also provides the application of the above-mentioned mutant genes of key genes whose expression is affected by sunlight in rice, and the mutant genes are used for:

(1) Inhibit rice tiller bud elongation;

and/or, (2) reduce the tiller number of rice.

The present invention uses different lighting conditions indoors and outdoors to treat rice seedlings, and uses transcriptome technology to identify different functional genes regulated by light, of which multiple genes are involved in photosynthesis. Among them, the RTN1 gene encodes fructose-1,6-bisphosphate aldolase. RTN1 is involved in regulating the elongation of rice tiller buds, thereby affecting the number of rice tillers and rice yield, providing a certain theoretical basis for research on rice yield formation. The present invention designs a method for identifying key genes expressed in rice that are affected by sunlight, and completes the functional verification of the RTN1 gene, clarifying the feasibility of the method, in order to further explore key genes regulated by light and improve crops. It lays the foundation for rice plant type and increased yield.

Description of the drawings

The above is only an overview of the technical solution of the present invention. In order to have a clearer understanding of the technical means of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Figure 1 shows the growth and different light treatment modes of rice materials;

Figure 2 shows the spectral information of outdoor sunlight and indoor greenhouse incandescent lamp conditions, where A is the relative spectral information under sunlight; B is the relative spectral information under indoor greenhouse (incandescent lamp) conditions.

Figure 3 shows the differentially expressed genes after treatment indoors and under the sun, where A is the differentially expressed genes after treatment indoors and under the sun; B is the co-expression result of genes indoors and under the sun.

Figure 4 shows the expression diagram of RTN1 that participates in photosynthesis and is induced by sunlight. A is the differentially expressed gene in photosynthesis; B is the expression of RTN1 induced by sunlight.

Figure 5 shows the phenotype of the RTN1 mutant showing few tillers. A is the gene information of the RTN1 mutant; B-D are the plant phenotypes of the wild type and mutants rtn1-1 and rtn1-2; E is the wild type and RTN1 mutant. Statistical results of tiller number.

Figure 6 shows the effect of RTN1 mutation on rice tiller bud elongation. A, B and C respectively represent the tiller bud tissue structure of the wild type ZH11, mutant rtn1-1 and rtn1-2 stem base parts; D, E and F represent the wild type respectively. Type ZH11, the tiller bud shoot tip longitudinal section of mutant rtn1-1 and rtn1-2 tiller bud tissue structure; G represents the tiller bud elongation of wild type ZH11, mutant rtn1-1 and rtn1-2.

Detailed ways

The following examples further illustrate the content of the present invention, but should not be understood as limiting the present invention. Without departing from the spirit and essence of the present invention, any modifications or substitutions made to the method, steps or conditions of the present invention shall fall within the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the biochemical reagents, carriers, consumables, etc. used in the examples are all commercially available products.

The present invention provides a method for identifying key genes expressed in rice that are affected by sunlight. The specific technical steps are as follows:

1. Two growth environments, indoor group and outdoor group, are used for the preparation of experimental materials.

(1) Rice cannot grow without the sun. Studies have found that rice grown under sunlight promotes the formation of tillers and the shape of the entire plant, ensuring stable food for us to eat. However, the number of tillers of rice grown under incandescent lamps in the greenhouse is significantly reduced, the ear development is incomplete, and sufficient rice yield cannot be obtained. At present, there are no reports on how sunlight affects gene expression in rice plants and thus affects the development of rice tiller buds and the formation of yield.

The present invention adopts two completely different growing environments, indoor group and outdoor group. The main difference lies in the lighting method. The indoor lighting method is mainly incandescent lamps, while the outdoor lighting method is natural sunlight (Figure 1). The light intensity and relative wavelength showed significant differences between the two growing conditions indoors and outdoors (Figure 2). The relative spectral value coverage in the relative wavelength range of outdoor sunlight is significantly higher than that of indoor incandescent conditions. The outdoor light intensity at the three light intensity detection time points of 9:00, 11:00 and 17:00 is also significantly higher than the indoor incandescent light condition.

(2) Sow the sprouted seeds into four blue boxes containing field soil, and place them under indoor conditions to grow. Rice seedlings that have grown for 21 days are used in the subsequent treatment experiments of the present invention. The seedlings in this period are in the tillering bud state. At the appropriate size stage, after being treated with sunlight and incandescent lamps, it is helpful to identify differentially expressed genes related to tiller bud development. The results are shown in Figure 1.

(3) Move 2 blue boxes with rice seedlings growing outdoors, and keep the remaining two indoors. All materials will continue to grow and grow at four growth time nodes (0 days, 3 days, 7 days and 15 days). ) for sampling, these four time points cover all time points from formation to elongation of rice tiller buds and are used for subsequent research (Figure 1).

2. Transcriptome analysis and identification of differentially expressed genes

The experimental materials prepared above were used and sent to Paisenno Company for RNA extraction, second-generation high-throughput RNA sequencing was carried out and corresponding bioinformatics technology analysis was completed. By analyzing the transcriptome data of 3 days, 7 days and 15 days of indoor and outdoor growth, we analyzed the identified differentially expressed genes and found that there were a large number of the same differences at three different time points, indoors under incandescent lights and outdoor sunlight. Expression genes, it was found that after 3 days of treatment, 1062 genes were up-regulated and 926 genes were down-regulated after sunlight treatment; after 7 days of treatment, 1766 genes were found to be up-regulated and 1158 genes were down-regulated after sunlight treatment; found After 15 days of treatment, 826 genes were up-regulated and 1566 genes were down-regulated after sunlight treatment. In addition, through co-expression analysis, it was found that 237 genes were differentially expressed at the three times. The results are shown in Figure 3.

Through the above identification method, the key genes differentially expressed by sunlight can be preliminarily identified.

In order to conduct in-depth research and confirm the feasibility of this identification method, the following analysis can be further performed.

3. Metabolic pathway analysis

Through metabolic pathway analysis, it was found that most of the above differentially expressed genes are involved in carbon fixation, citrate cycle, tyrosine metabolism, glycolysis/gluconeogenesis, fructose and mannose metabolism, pentose phosphate pathway and photosynthesis of photosynthetic organisms. way.

4. Identification of differentially expressed genes involved in photosynthesis

Through analysis of differentially expressed genes, it was identified that multiple genes involved in the rice photosynthesis pathway showed significant differences in RNA transcript levels under indoor and outdoor environmental conditions, including those encoding fructose-1,6-bisphosphate aldolase. Gene RTN1, fructose-1,6-bisphosphate aldolase genes FBA2 and FBA4, fructose-1,6-bisphosphatase MOC2, ribulose 1,5-bisphosphate carboxylase/oxygenase encoding gene OsRBSC1-4 , the phosphoribulokinase encoding gene OsPRK. Among them, the expression difference of MOC2 was the most obvious, followed by the expression difference of RTN1, while the expression differences of other genes were slightly smaller. In addition, we used qRT-PCR analysis technology to verify the expression of the identified RTN1 gene, and the results showed that the expression of this gene is induced by sunlight (Figure 4).

5. Functional verification of differentially expressed genes involved in photosynthesis

(1) The present invention speculates that genes regulated by light may be involved in the growth and development of rice. Therefore, we screened the RTN1 gene as a target gene, edited it using CRISPR/Cas9 gene editing technology, and created mutants in the background of the japonica rice variety ZH11. The gene sequencing results of materials rtn1-1 and rtn1-2 showed that a base insertion and deletion occurred in the second exon of the gene respectively, and the encoded protein sequence changed. The mutated protein underwent frameshift, resulting in protein Functional changes (Fig. 5A).

(2) Through phenotypic analysis of plant tiller number, it was found that compared with wild-type ZH11, the number of tillers in both mutants was significantly reduced, indicating that the RTN1 gene regulates the number of tillers in rice (Figure 5B, Figure 5C and Figure 5D). Through histological section experiments and bud anatomy experiments, it was found that the axillary buds of the two mutants could form normally during the development of tiller buds, but the elongation of the tiller buds was abnormal. The results are shown in Figure 6. Figure 6A, Figure 6B and Figure 6C respectively represent the tiller bud tissue structure of the stem base of wild-type ZH11, mutant rtn1-1 and rtn1-2; Figure 6D, Figure 6E and Figure 6F respectively represent wild-type ZH11 and mutant rtn1-1 and rtn1-2 tiller bud shoot tip longitudinal section tiller bud tissue structure; Figure 6G shows the tiller bud elongation of wild type ZH11, mutant rtn1-1 and rtn1-2.

A detailed description will be given below through examples.

Example 1. Preparation of rice materials using two growing environments: indoor group and outdoor group

(1) This embodiment includes two growth environments: indoor group and outdoor group: indoor group growth conditions settings: lighting mode, incandescent lamp; light time: 5:00 am to 19:00 pm; dark time: 19:00 pm to 5:00 a.m. the next day. Settings for the growth conditions of the outdoor group: lighting method, natural sunlight; light time, 5:00 am to 19:00 pm; dark time, 19:00 pm to 5:00 am the next day. The temperature and humidity conditions of the two growing environments, indoor and outdoor, should be kept as consistent as possible. Light intensity measurement uses a spectrometer HR-550 to measure the light intensity of different indoor and outdoor light sources. The measurement times are 9:00, 11:00 and 17:00.

(2) Prepare four blue boxes (length x width x height: 75cm The seeds of the japonica rice variety Nipponbare are soaked in water for 48 hours, and then germinated at 35 degrees for 24 hours. The germinated seeds are then sown in the soil of four blue boxes, with a certain distance between each seed and a row spacing of 5 cm. X5 cm to facilitate the growth of seedlings. Rice seedlings grown for 21 days after sowing were used as experimental materials prepared in advance.

(3) Sample the rice seedlings after 0 days, 3 days, 7 days and 15 days of indoor and outdoor treatment. The rice seedlings are pulled out from the soil, and then the soil on the roots is cleaned with water, and the water is soaked up with paper for later use. The sampling part is the 0.3cm stem base tissue of rice seedlings. Cut it out with a scalpel and wrap it in tin foil. Samples are taken indoors and outdoors independently. Each sample contains the stem base tissue of 10 seedlings. There are three replicates, and then quickly placed in liquid nitrogen. Freeze in medium and store at -80°C for later use.

Example 2. Outdoor sunlight affects the expression of plant genes

(1) Extraction of RNA from rice tissue

Take out the spare tissue sample and grind it with liquid nitrogen. Then put the powder sample into a 1.5mL centrifuge tube frozen in liquid nitrogen. Use the TRIZOL method to extract total rice RNA. The extracted RNA is used for concentration measurement with Nanodrop2000 instrument. Samples that meet the requirements for RNA extraction quality (OD260/280 greater than 1.9) and concentration (total concentration greater than 5 micrograms) are sent to the company to complete library construction and sequencing.

(2) Transcriptome sequencing analysis

Transcript paired-end sequencing was performed on an Illumina HiSeq 2500 instrument, low-quality reads were filtered, and the remaining sequencing sequences were aligned to the reference genome Nipponbare, and the complete files on the alignment were processed by Cufflinks software. The significance level for differentially expressed transcripts was set at a q value <0.05.

Example 3. RTN1 mutant exhibits fewer tillers phenotype

In the preliminary research of this invention, differentially expressed gene information and metabolic pathway analysis were used to identify that the expression of multiple genes is regulated by sunlight and participate in photosynthesis. Therefore, it is inferred that these genes are involved in regulating the plant type of rice, and the target gene RTN1 was locked and carried out. Genetic material creation and functional verification.

Based on the complete genome and cDNA sequence of the rice variety Oryza sativa L cv. Nipponbare provided in NCBI, the specificity of gene knockout of the RTN1 candidate gene was designed through the general target design website http://crispr.dbcls.jp/ For a strong target sequence, the present invention combines the characteristics of the expression vector and the RTN1 gene sequence, and adds specific linker sequences at both ends of the specific target.

The specific designed primer requirements are: add the adapter sequence CAG to the 5' end of the forward primer (RTN1-F), and add the adapter sequence ACC to the 5' end of the reverse primer (RTN1-R). The specific primer sequence information is as follows:

RTN1-F forward primer: 5'- cag GAACGTGGAGCCCAACCGCC-3'

RTN1-R reverse primer: 5'- aac GGCGGTTGGGCTCCACGTTC-3'

Use the primers (RTN1-F and RTN1-R) designed and synthesized above, dissolved in 50uL of double-distilled water, the final concentration of the primers is 10μM, and annealed to form primer dimers. The specific annealing procedure is as follows: 95 degrees for 3 minutes. Cool slowly from 95 degrees to 25 degrees, set the program to -1℃/10 seconds, naturally cool to room temperature, and finally 25 degrees for 5 minutes.

The prepared primer-dimer is connected to the target vector. The specific reaction system is: 1 μl of Cas9/gRNA vector; 1 μl of primer-dimer; 1 μl of T ₄ ligase; 1 μl of T ₄ ligation buffer. The water bath temperature is set to 16 degrees and incubated overnight (more than 12 hours), and then transformed into E. coli DH5a competent cells, and then screened for positive clones through kanamycin resistance, and sent the positive clones to Hangzhou Qingke Company for sequencing, and finally successfully connected The expression plasmid Cas9-RTN1. The Cas9-RTN1 expression plasmid was transferred into Agrobacterium tumefaciens EHA105 using the liquid nitrogen freeze-thawing method for later use.

Prepare the callus of Zhonghua 11 seeds in advance. Peel the seeds, then wash them with 75% alcohol, then disinfect them in 3% hypochlorous acid solution for 45 minutes, wash them three times with sterilized water, and absorb them with sterilized filter paper. Dry the water and sow the seeds in NB medium. Then Agrobacterium carrying the Cas9-RTN1 expression plasmid was infected with Zhonghua 11 calli, and then screened on NB medium with a concentration of 50 mg hygromycin, seedlings were differentiated in a differentiation medium with a concentration of 50 mg hygromycin, and seedlings were differentiated with a concentration of 50 mg hygromycin. Hygromycin rooting medium was used to screen positive plants, and transgenic seedlings were finally obtained (guaranteing 30 positive seedlings) and transplanted to the field for identification and analysis.

Using transgenic seedlings, about 0.1 gram of leaves from a single plant at the seedling stage is used to extract the total plant DNA, and the RTN1 gene target sequence is sequenced to determine whether the gene has been edited. The specific sequencing primers are as follows:

RTN1-seq-F:ACACTGTAGCGGCCACTG

RTN1-seq-R: CCTCCACTGCTCCACATCTT

The amplification program was as follows: pre-denaturation at 94°C for 4 minutes; denaturation at 94°C for 30 seconds, annealing at 55°C for 30 seconds, extension at 72°C for 30 seconds, 40 cycles; and finally extension at 72°C for 10 minutes. The PCR products were separated by 5% agarose gel electrophoresis and sent to the company Qingke for sequencing. Finally, the mutated RTN1 target sequence of each transgenic seedling was obtained. The created RTN1 mutants were finally used for statistical analysis of rice tiller number.

In summary, the present invention has designed a method for identifying key genes expressed in rice that are affected by sunlight, and has completed functional verification of the RTN1 gene, clarifying the feasibility of this method and providing a basis for further exploring the key factors regulated by light. Genes lay the foundation for improving crop plant type and increasing yield.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Those skilled in the art may make some simple modifications, equivalent changes or modifications using the technical contents disclosed above, and they all fall within the scope of this invention. within the scope of protection of the invention.

Claims (10)

1. A method for identifying key genes whose expression is affected by sunlight in rice, characterized by comprising the following steps: (1) Rice seedlings are treated under two different conditions, indoors and outdoors, where the indoor lighting method is incandescent lamps and the outdoor lighting method is natural sunlight; (2) Set different treatment time points to sample seedlings; (3) Conduct transcriptome analysis on the sampled samples to identify key genes differentially expressed by sunlight. 2. The identification method of key genes expressed by sunlight in rice according to claim 1, characterized in that in the step (1), the light intensity and relative wavelength of two different conditions, indoor and outdoor, show Significant differences; among them, the relative spectral value coverage in the relative wavelength range of outdoor sunlight is significantly higher than that of indoor incandescent light conditions; the outdoor light intensity is also significant at the three light intensity detection time points of 9:00, 11:00 and 17:00. Higher than indoor incandescent lighting conditions. 3. The identification method of key genes expressed under the influence of sunlight in rice according to claim 1, characterized in that in the step (1), the rice seedlings are rice seedlings grown indoors for 21 days, and The germinated seeds were sown into boxes containing field soil and placed indoors under incandescent lighting conditions to grow for 21 days. 4. The identification method of key genes expressed by sunlight in rice according to any one of claims 1-3, characterized in that, in the step (1): Setting of indoor conditions: incandescent lighting time, 5:00 am to 19:00 pm; dark time, 19:00 pm to 5:00 am the next day; Setting of outdoor conditions: natural sunlight lighting time, 5:00 am to 19:00 pm; dark time, 19:00 pm to 5:00 am the next day. 5. The identification method of key genes expressed by sunlight in rice according to any one of claims 1-3, characterized in that in the step (2), 0 days, 3 days, 7 days and The stem base tissues of rice seedlings treated indoors and outdoors were sampled at the 15-day treatment time point or at the 3-day, 7-day and 15-day treatment time points. 6. The method for identifying key genes expressed under the influence of sunlight in rice according to any one of claims 1 to 5, characterized in that in step (3) transcriptome analysis and identification are performed to obtain differentially expressed key genes. Finally, metabolic pathway analysis was performed, and the functions of differentially expressed genes involved in photosynthesis were verified. 7. An application of key genes whose expression is affected by sunlight in rice, characterized in that the key genes participate in rice photosynthesis and are used to control rice growth and development and rice plant type. 8. Application of key genes expressed by sunlight in rice according to claim 7, characterized in that the key gene is encoding fructose-1,6-bisphosphate aldolase gene RTN1, and the RTN1 gene The sequence of is shown in Seq ID No: 1, and the protein sequence of the RTN1 gene is shown in Seq ID No: 2. The gene is used for positive regulation: (1) Elongation of rice tiller buds; (2) Number of rice tillers; and/or (3) rice yield. 9. A mutant gene of a key gene whose expression is affected by sunlight in rice, characterized in that the mutant gene has a base C insertion mutation sequence at position 154 of the sequence shown in Seq ID No: 1, Or a sequence in which one base C is deleted at position 154 of the sequence shown in Seq ID No: 1. 10. Application of a mutant gene of a key gene whose expression is affected by sunlight in rice according to claim 9, characterized in that the mutant gene is used for: (1) Inhibit rice tiller bud elongation; and/or, (2) reduce the tiller number of rice.