Application of straw compost in rice planting and detection method

Abstract

The invention relates to application of straw compost in rice planting and a detection method, and belongs to the technical field of saline-alkali soil planting. The application and the method comprise the influence of the corn straw compost on the rice yield, the soil enzyme activity, the rice photosynthesis and other elements. Transcriptomics analysis is used, the corn straw compost is mixed in the saline-alkali soil, growth of rice under saline-alkali stress is effectively promoted, the corn straw compost is in direct proportion to the compost dosage, photosynthesis can be improved, the content of secondary metabolites is increased, amino acid metabolism is changed, and rice is helped to better adapt to the saline-alkali environment. Meanwhile, through multiple groups of experiments, the influence of the corn straw compost on the saline-alkaline tolerance of the rice is researched and analyzed from the gene level, and the method has important significance on subsequent research on the saline-alkaline tolerance of the rice.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land planting, and particularly relates to an application of straw compost in rice planting and a detection method. Background Art

[0002] Saline-alkali land is a type of barren and degraded soil that seriously affects global crop yields and ecological development. The saline-alkali land in Northeast China mainly contains carbonates such as sodium bicarbonate and sodium carbonate, so it is also called soda saline-alkali land. + The lack of nutrients and fertility seriously inhibits the growth and development of plants.

[0003] The effects of soda saline-alkali soil on plants include salt stress and alkali stress. Salt stress mainly comes from Na + , Na + It can directly enter the cell through channels and carrier proteins, causing ion toxicity. At the same time, the high ion concentration outside the cell will reduce the osmotic potential, drive water molecules out of the cell, and cause physiological drought, which is called osmotic stress. Both aspects will lead to the destruction of plant metabolites. Alkaline stress is mainly caused by CO3 2- and CHO 3- Induction, pH value further increases on the basis of salt stress. High pH value will seriously damage the stability of cell pH value, destroy the integrity of cell membrane, and reduce root activity and photosynthetic function.

[0004] The traditional methods for improving soda saline-alkali land are mainly physical and chemical methods. These methods include using gypsum, black alum and other improvers to reduce or eliminate soil alkalinity and improve soil physical and chemical properties, as well as improving soil structure and composition through deep plowing or construction of water conservancy projects. However, these methods require large construction volumes, are costly, and have a long effective period, which is not worth the cost.

[0005] In recent years, biological methods have been continuously developed and have shown good results. These methods have the advantages of being environmentally friendly, cost-effective and sustainable. In view of this, the present invention aims to disclose an application of improving saline-alkali land by biological methods. Summary of the invention

[0006] The purpose of the present invention is to provide an application of straw compost in rice planting and a detection method, so as to improve the current situation of saline-alkali land planting and improve land utilization rate through biological methods.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: An application of straw compost in rice planting comprises: 1. Promoting yield: Promoting the number of grains per panicle and the number of tillers of rice; 2. Optimize soil: improve soil fertility, promote soil enzyme activity, and endow rice with salt-alkali tolerance; 3. Promote photosynthesis: increase net photosynthetic rate, stomatal conductance and chlorophyll content; 4. Promote active oxygen homeostasis: reduce the degree of peroxidation of rice; 5. Improve metabolites: Promote the content of antioxidants in rice metabolites.

[0008] Further, the following steps are included: Step 1: Prepare saline-alkali soil, corn straw compost, and rice seedlings of saline-alkali sensitive varieties; Step 2: Mix the salinized soil with corn straw compost and divide the soil into several experimental groups according to the different proportions of corn straw compost; Step 3: Mix the salinized soil with gypsum as the control soil; Step 4: Plant rice seedlings in pots in the above-mentioned experimental group soil and control group soil, grow them under natural conditions, and the growth period is from late April to mid-October, and finally obtain groups of mature rice samples corresponding to the experimental group soil and control group soil.

[0009] Preferably, the number of soil groups in the experimental group is no less than four.

[0010] A method for detecting application of straw compost in rice planting comprises the following steps: S1: Manually calculate the number of tillers at the tillering stage, the number of tillers at the maturity stage, and the average grain weight per ear of rice at maturity stage for each experimental group and the control group; S2: Detecting the enzyme activity of the soil, wherein the urease in the soil of each experimental group and the control group was determined by the indophenol blue colorimetric method, and the sucrase was determined by the 3,5-dinitrosalicylic acid colorimetric method; S3: Use a photosynthetic meter to measure the net photosynthetic rate, stomatal conductance and intercellular CO2 concentration of rice leaves in each group; S4: Use a chlorophyll meter to measure the chlorophyll content of rice leaves in each group; S5: The free radical scavenging abilities of DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP (ferric reducing antioxidant capacity) of rice leaves in each group were measured using a total antioxidant capacity assay kit; S6: Detection of total flavonoid content (TFC) and total phenol content (TPC) in rice leaves of each group S7: RNA-seq and RT-qPCR analysis experiments were performed on each group of rice.

[0011] Furthermore, the number of tillers in the tillering stage of rice, the number of tillers in the maturity stage of rice and the average grain weight per ear of rice in the maturity stage were positively correlated with the proportion of corn straw compost in the soil.

[0012] Furthermore, the net photosynthetic rate, stomatal conductance, and chlorophyll content of rice leaves were positively correlated with the proportion of corn straw compost in the soil, and the intercellular CO2 concentration was not affected.

[0013] Furthermore, the free radical scavenging activities of ABTS, FRAP, and DPPH of rice leaves were negatively correlated with the proportion of corn straw compost in the soil.

[0014] Furthermore, the total flavonoids and total phenolic contents in rice leaves were positively correlated with the proportion of corn straw compost in the soil.

[0015] The beneficial effects of the present invention are: Using biological methods, by mixing corn straw compost in saline-alkali soil, the growth of rice under saline-alkali stress can be effectively promoted, and the amount of compost is proportional to the amount of compost used. It can also improve photosynthesis, increase the content of secondary metabolites, change amino acid metabolism, and help rice better adapt to the saline-alkali environment.

[0016] At the same time, the present invention also explores and analyzes the effect of corn straw compost on the salt-alkali tolerance of rice from a genetic level through multiple groups of experiments, which is of great significance for subsequent research on the salt-alkali tolerance of rice.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an experimental data diagram of the application of straw compost in rice planting and the detection method shown in Example 1 of the present invention; Figure 2 This is an experimental data diagram of the effect of corn straw compost on soil enzyme activity and rice physiological activity shown in Example 2 of the present invention; Figure 3 This is a schematic diagram summarizing the differentially expressed genes in rice shown in Example 3 of the present invention; Figure 4 Schematic diagram of k-means cluster analysis of DEGs shown in Example 3 of the present invention; Figure 5 Schematic diagram of identifying key gene functions and pathways in DEGs shown in Example 3 of the present invention; Figure 6 This is a schematic diagram of Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DEGs shown in Example 3 of the present invention; Figure 7 It is a relative expression heat map of DEGs enriched in metabolic pathways by EGG analysis as shown in Example 3 of the present invention; Figure 8 This is a schematic diagram of the verification results of the RT qPCR detection of gene expression levels shown in Example 3 of the present invention; Fig. 9 This is a schematic diagram of the weighted correlation network analysis (WCGNA) analysis shown in Example 3 of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Experimental materials: The saline-alkali soil was obtained from Durbet Mongolian Autonomous County, Heilongjiang Province (46° 51′N, 123° 30′E), pH = 10.11; The rice used was the salt-alkali sensitive variety Wuyoudao No. 4, and the rice seedlings were provided by the Longping Weak Alkali Experimental Base; Corn straw compost was produced by the Microbiology Laboratory of Qiqihar University; Experimental location: Qiqihar University campus, Qiqihar City, Heilongjiang Province, China (47 16'N, 123 55'E).

[0022] Experimental Control: Gypsum was used as a positive control.

[0023] Corn straw compost was evenly mixed with salinized soil and divided into four groups according to different mixing ratios. The control group selected soil obtained by mixing gypsum and salinized soil, and the above five groups of soil were numbered.

[0024] See Table 1 for the numbers and corresponding soil components serial number Soil composition FD0 0% corn straw compost + 100% saline soil FDS 7.7% gypsum + 92.3% saline soil (control) FD10 10% corn straw compost + 90% saline soil FD30 30% corn straw compost + 70% saline soil FD50 50% corn straw compost + 50% saline soil Table 1 The rice seedlings were potted in the five groups of mixed soils mentioned above and grown under natural conditions from late April to mid-October, and finally five groups of mature rice samples with corresponding numbers were obtained. Example

[0025] The average number of grains per panicle and the number of tillers in the above five groups of rice at the tillering and maturity stages were statistically analyzed. The experimental results are as follows: Figure 1 As shown, where: (a) Average grain weight per ear of rice at each maturity stage.

[0026] (b): Number of tillers in the tillering stage of rice of each number.

[0027] (c): Number of tillers at maturity of each rice variety.

[0028] Data are mean ± SD, n = 3, * p < 0.05, ** p < 0.01, *** p < 0.001. ns indicates no significant difference at p < 0.05.

[0029] It can be seen that adding corn straw compost has a promoting effect on rice yield under saline-alkali stress.

[0030] Compared with FD0, the grain weight and tiller number of FDS did not change significantly. After applying corn straw compost, the grain weight and tiller number increased significantly, and the increase in rice yield became more obvious with the increase in fertilizer application. FD50 had the most significant effect on increasing rice yield under saline-alkali conditions. The above results show that corn straw compost can effectively alleviate the growth of rice under saline-alkali stress, promote rice yield, and have a positive correlation. Example

[0031] The experimental detection of physiological activity of harvested rice includes the following steps: 1. Detect the soil enzyme activity of each number. The specific process is as follows: 1. Determine urease using the indophenol blue colorimetric method. Weigh 5 g of air-dried soil sample, add 1 mL of toluene, and let stand for 15 minutes. Then add 10 mL of 10% urea solution and 20 mL of citric acid solution (pH = 6.7) and mix carefully. After culturing at 37°C for 24 hours, dilute to 100 mL with 38°C water, shake carefully, take 3 mL of filtrate in a 50 mL volumetric flask, add 10 mL of distilled water, shake well, add 4 mL of sodium phenol, and then add 3 mL of sodium hypochlorite, let stand for 20 minutes, dilute to 50 mL with water, and the solution turns blue. No soil was added to the control group, and the absorbance value was measured at 578 nm.

[0032] 2. Sucrase is determined by 3,5-dinitrosalicylic acid colorimetry. Inject 15 ml of 8% sucrose solution, 5 ml of pH=5.5 phosphate buffer solution and 5 μl of toluene into 5 g of air-dried soil. Shake well and incubate at 37°C for 24 hours. Filter quickly. Take 1 mL of filtrate, add 3 mL of 3,5-dinitrosalicylic acid solution, and cool rapidly in a boiling water bath for 5 minutes and continue for 3 minutes. The solution turns orange-yellow and is finally diluted to 50 ml with distilled water. No soil is added to the control group, and the absorbance value is measured at 508 nm.

[0033] 2. Detect the activity of rice leaves of each number. The specific process is as follows: 1. Use the LI-6400XT portable photosynthetic meter to measure the net photosynthetic rate, stomatal conductance and intercellular CO2 concentration.

[0034] 2. Use SPAD-502 chlorophyll meter to measure chlorophyll content.

[0035] 3. Detect the free radical scavenging ability of DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP (ferric reducing antioxidant capacity) of rice leaves of each number using the total antioxidant capacity assay kit produced by Shanghai ELISA Biotechnology Co., Ltd. The specific process is as follows: 1. Mix 50 μL of the supernatant from each group of rice leaves with 950 μL of DPPH solution, incubate in the dark at room temperature for 30 min, and then measure at 515 nm using a microplate photometer. The DPPH free radical scavenging activity was calculated as [(A1-A2) ÷ A1] × 100%, where A1 and A2 represent the absorbance of the blank and test sample, respectively.

[0036] 2. Add 50 μL of each rice leaf extract to 950 μL of ABTS solution, incubate for 20 min, and then measure the absorbance at 734 nm. ABTS values ​​are calculated in mmol / g.

[0037] 3. Add 50 μL of the rice leaf supernatant from each group to 950 μL of FRAP solution, incubate for 20 minutes, and then measure the absorbance at 593 nm using a microplate reader. The results are calculated as the concentration of the extract with iron reducing capacity corresponding to 1 mM FeSO4 (mmol / g).

[0038] 4. Detect the total flavonoid content (TFC) and total phenol content (TPC) in the rice leaves of each number. The specific process is as follows: The dried rice leaf samples were crushed through a 60-mesh sieve, 0.1 mg was weighed, and 5 ml of 80% ethanol was added. Ultrasonic extraction was performed at 70 °C for 60 min. A flavonoid calibration curve was drawn using 10-100 g / mL rutin, the absorbance of the water extract at 510 nm was measured, and the total flavonoid content in the rice leaves was calculated. A total phenol calibration curve was constructed using anhydrous methanol as a control and gallic acid (5-200 μ g / mL) as a standard sample. The absorbance of each sample was measured at a wavelength of 735 nm using a spectrophotometer, and the total phenol content of the rice leaves was calculated.

[0039] The results of the above experimental tests are as follows Figure 2 As shown, where: (a) Determination of urease in soil of each number; (b) Determination of sucrase in soil of each number; (c) Net photosynthetic rate of rice leaves of each number; (d) Stomatal conductance of rice leaves of each number; (e) SPAD determination of rice leaves of each number; (f) Intercellular CO2 in stomatal conductance of rice leaves of each number; (g) ABTS assay of rice leaves of each number; (h) FRAP measurement of rice leaves of each number; (i) DPPH determination of rice leaves of each number; (j) Total flavonoids content (TFC) in rice leaves of each number; (k) Total phenolic content in rice leaves of each number; Data are mean ± SD, n = 3, * p < 0.05, ** p < 0.01, *** p < 0.001. ns indicates no significant difference at p < 0.05.

[0040] Salt-alkali stress can inhibit rice growth, destroy rice active oxygen homeostasis, photosynthesis and material metabolism. From the above test results, we can see that adding corn straw compost can alleviate the adverse effects of salt-alkali stress.

[0041] After testing the activity of soil enzymes, it was found that adding corn straw compost can promote the activity of urease and sucrose, improve soil fertility, and give rice a certain salt-alkali tolerance. Testing of rice leaf photosynthesis showed that corn straw compost can improve rice photosynthesis, increase net photosynthetic rate, stomatal conductance and chlorophyll content, and has no significant effect on intercellular CO2 concentration. The test of free radical cation scavenging activity showed that compared with salt-alkali stress, the free radical scavenging activity of ABTS, FRAP and DPPH in rice was significantly reduced after adding corn straw compost ( Figure 2gi). The contents of total flavonoids and phenolic compounds in rice treated with corn straw compost increased significantly.

[0042] These results indicate that corn straw composting can alleviate the effects of salinity-alkali stress on rice root enzyme activity, leaf photosynthesis, reactive oxygen homeostasis, and metabolites. Example

[0043] The harvested rice was subjected to RNA-seq and RT-qPCR analysis experiments, including the following steps: RNA sequencing was performed on the Illumina NovaSeq 6000 platform by Shanghai Major Bio-pharm Biotechnology Co., Ltd. using rice flag leaves of each numbered sample. The RNA seq data were compared with the rice reference genome using the default HISAT2 settings, and then transcriptome analysis and quantification were performed using StringTie. Differential gene expression was analyzed using DESeq2 and default parameters, and gene expression heat maps were drawn using FPKM values ​​and visualized using TBtools.

[0044] The abundance of selected genes was analyzed by qPCR (Bio RAD) using SYBR Green Master Mix and CFX96 Real-Time System. The program was as follows: 95 °C for 2 min, followed by 40 cycles at 95 °C for 15 s and 60 °C for 20 s. The UBQ5 gene was used as an endogenous control. Transcript levels were calculated using the 2-δδCT method.

[0045] The experimental results are as follows: First, transcriptome analysis of rice leaves grown under FD0, FDS, FD10, FD30, and FD50 conditions was performed. A total of 101.72 GB of clean data was generated. After filtering, 224.69 Mb of clean reads were obtained, with Q30>93% and GC content ranging from 49.85% to 51.37%, see Table 2.

[0046] serial number Raw reads (Mbytes) Raw_bases (Gb) clear_read(Mbytes) Clean Base (Gb) Q20（%） Q30（%） GC (%) FD0 44.05 6.50 43.43 6.16 95.993 93.63 50.61 Control group 46.34 6.83 45.70 6.49 95.94 93.55 49.85 FD10 47.11 6.95 46.53 6.64 95.74 93.28 50.38 FD30 43.19 6.37 42.58 6.08 95.66 93.15 51.37 FD50 44.01 6.49 43.40 6.20 95.71 93.21 50.83 Table 2 RNA sequencing data quality The above results confirmed the high quality of the transcripts.

[0047] 2. Identification of the effects of corn straw composting on DEGs 1. Principal component analysis (PCA) revealed significant differences between the FD0 and FDS / 10 / 30 / 50 groups. PC1 contributed 33.93% to distinguishing the samples, while PC2 contributed 22.65% to distinguishing the samples ( Figure 2A). A total of 6364 differentially expressed genes (DEGs) were identified using DESeq software. 1799 genes were upregulated and 1265 genes were downregulated in FD0 compared to FD10; 1830 upregulated and 1033 downregulated DEGs in FD0 relative to FD30; 1729 upregulated and 1066 downregulated DEGs in FD0 relative to FD50; 1396 upregulated and 2146 downregulated DEGs in FD0 relative to FDS. Using Venn analysis of common differentially expressed genes, 645 genes were found to be changed in all four transcriptomes, see Figure 3 ,in: (a) PCA analysis of the transcriptome; (b) Statistics of DEGs: FD10 / 30 / 50 / S_VS_FD0; (c) Heat map showing the relative expression levels of DEGs under different treatments; (d) Venn diagram depicting the overlap of DEGs. Circles show only specific sites.

[0048] The transcription patterns of all DEGs were analyzed by kmeans, and five major expression patterns were identified, and the highest expression levels were achieved under each of the five treatments. Some genes have completely opposite expression patterns, such as genes in subclass 1 and subclass 2, see Figure 4 .

[0049] 2. Gene set enrichment analysis was performed to identify key gene functions and pathways in a large number of DEGs and retrieve individual genes from highly represented gene ontology (GO) categories. For each treatment, the top 20 enriched ontologies were reviewed.

[0050] Most of the enriched ontologies in FD0_vs_FDS and FD0_vs_FD10 / 30 / 50 were different. FD0_vs_FD10 / 30 / 50 were enriched in many aspects related to cell wall (e.g., cell wall macromolecule decomposition process, GO:0044039; xylan decomposition process, GO:0045493) and photosynthesis (e.g., photosynthesis, GO:0015979; photosynthesis, light harvesting, GO:0009765), while FD0_vs_FDS were more enriched in cellular detoxification (GO:1990748) and detoxification (GO:0098754). In FD30_VS_FD0, there were no pathways related to photosynthesis, and the vast majority were cell wall-related pathways. Photosynthesis- and cell wall-related pathways were observed in FD310_VS_FD0 and FD50_VS_FD0.

[0051] Maintenance of cell wall integrity is critical for the response to salt stress. Under salinity stress, cell wall integrity was disrupted, and pathways associated with the rice cell wall were reprogrammed when corn stover compost was added. At the same time, significant changes occurred in the photosynthesis pathway, see Figure 5 , where the red arrows represent the correlation with photosynthesis.

[0052] 3. KEGG pathway analysis was performed on common DEGs to better understand their functional relevance in alleviating salt stress through corn straw composting. There are three main types of KEGG pathways related to photosynthesis, phenylpropanoid biosynthesis, and amino acid biosynthesis. These three pathways can be found in both FD50_VS_FD0 and FDS_VS_FD0. Phenylpropanoid biosynthesis and amino acid biosynthesis are more prominent in FD10_VS_FD0; compared with FD0, there was no significant increase in photosynthesis-related pathways in FD30, but the biosynthesis of phenylpropanoids and flavonoids increased. The biosynthesis of phenylpropanoids is closely related to the cell wall. The enrichment analysis of KEGG and GO can confirm each other, which together shows that plant photosynthesis, phenylpropanoid biochemistry, and amino acid biosynthesis play an important role in alleviating salt-alkali stress. Please refer to Figure 6 , where the red arrows represent correlations with photosynthesis, the grey arrows represent correlations with amino acid metabolism, and the blue arrows represent correlations with flavonoid biosynthesis (including phenylpropionic acid metabolism).

[0053] 3. Detection of gene expression levels 1. Find differentially expressed genes in photosynthesis (photosynthesis, map00195 photosynthesis-antenna proteins, map00196 and carbon fixation in photosynthetic tissues), phenylpropanoid biosynthesis (phenylpropanoid biosynthesis, map00940 flavonoid biosynthesis, map00941 flavonoid and flavonol biosynthesis, map00944), and amino acid biosynthesis (phenylalanine metabolism, map00360 valine, leucine and isoleucine biosynthesis, map00290 cysteine ​​and methionine metabolism, map00270 glycine, serine and threonine metabolism, map00260 tyrosine metabolism; alanine, map00350 aspartate and glutamate metabolism, map00250), and draw heat maps based on FPKM, see Figure 7 ,in: (a): photosynthesis; (b): phenylpropanoid biosynthesis; (c): Amino acid biosynthesis.

[0054] Red represents up-regulation, blue represents down-regulation, and Z-score homogenization was used.

[0055] 2. Some genes have been studied. For example, Os07g0147500 encodes the photosystem II polypeptide OsPsbR1. Rice plants overexpressing OsPsbR1 have higher photosynthetic rates and stronger cold tolerance.

[0056] In the above three pathways, 9 genes were randomly selected for qRT-PCR to verify the fold changes of DEGs. The consistency between the fold changes of these DEGs and RNA seq results indicates the reproducibility of the data, see Figure 8 , ai represents different genes.

[0057] 3. Weighted correlation network analysis (WGCNA) can identify co-expressed gene modules and explore the correlation between gene networks and phenotypes of interest, as well as core genes in the network. This helps to reveal the mechanism by which corn straw composting alleviates salinity-alkali stress in rice growth.

[0058] Rice genes are divided into 17 modules (colors) based on FPKM, and the expression of each color module is different under different treatments. The turquoise module has the largest number of genes, containing 4288 genes, while the gray 60 module has the least number of genes, at 74. See Fig. 9 ,in: (a): Module segmentation; (b): Correlation heatmap of modules with traits in different treatment groups.

[0059] Summarize In summary, combined with the experimental data results of rice physiological data and RNA sequencing, corn straw compost can effectively promote the growth of rice under saline-alkali stress, and is proportional to the amount of compost used. It can also improve photosynthesis, increase the content of secondary metabolites, change amino acid metabolism, and help rice better adapt to saline-alkali environments.

[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An application of straw compost in rice planting, characterized in that: Including the following aspects: 1). Promoting yield: Promoting the number of grains per panicle and the number of tillers of rice; 2). Optimize soil: improve soil fertility, promote soil enzyme activity, and endow rice with salt-alkali tolerance; 3). Promote photosynthesis: increase net photosynthetic rate, stomatal conductance and chlorophyll content; 4). Promote the homeostasis of active oxygen: reduce the degree of peroxidation of rice; 5). Improve metabolites: Promote the content of antioxidants in rice metabolites.

2. The application of straw compost in rice planting as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Prepare saline-alkali soil, corn straw compost, and rice seedlings of saline-alkali sensitive varieties; Step 2: Mix the salinized soil with corn straw compost and divide the soil into several experimental groups according to the different proportions of corn straw compost; Step 3: Mix the salinized soil with gypsum as the control soil; Step 4: Plant rice seedlings in pots in the above-mentioned experimental group soil and control group soil, grow them under natural conditions, and the growth period is from late April to mid-October, and finally obtain groups of mature rice samples corresponding to the experimental group soil and control group soil.

3. The application of straw compost in rice planting as claimed in claim 1, characterized in that: The number of soil groups in the experimental group is no less than four.

4. A detection method for application of straw compost in rice planting, applied to the application of straw compost in rice planting according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Manually calculate the number of tillers at the tillering stage, the number of tillers at the maturity stage, and the average grain weight per ear of rice at maturity stage for each experimental group and the control group; S2: Detecting the enzyme activity of the soil, wherein the urease in the soil of each experimental group and the control group was determined by the indophenol blue colorimetric method, and the sucrase was determined by the 3,5-dinitrosalicylic acid colorimetric method; S3: Use a photosynthetic meter to measure the net photosynthetic rate, stomatal conductance and intercellular CO2 concentration of rice leaves in each group; S4: Use a chlorophyll meter to measure the chlorophyll content of rice leaves in each group; S5: The free radical scavenging abilities of DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP (ferric reducing antioxidant capacity) of rice leaves in each group were measured using a total antioxidant capacity assay kit; S6: Detect the total flavonoid content (TFC) and total phenolic content (TPC) in rice leaves of each group; S7: RNA-seq and RT-qPCR analysis experiments were performed on each group of rice.

5. The detection method for application of straw compost in rice planting as claimed in claim 4, characterized in that: The number of tillers in the tillering stage of rice, the number of tillers in the maturity stage of rice and the average grain weight per ear of rice in the maturity stage were positively correlated with the proportion of corn straw compost in the soil.

6. The detection method for application of straw compost in rice planting according to claim 4, characterized in that: The net photosynthetic rate, stomatal conductance and chlorophyll content of rice leaves were positively correlated with the proportion of corn straw compost in the soil, and the intercellular CO2 concentration was not affected.

7. The detection method for application of straw compost in rice planting as claimed in claim 4, characterized in that: The free radical scavenging activities of ABTS, FRAP, and DPPH in rice leaves were negatively correlated with the proportion of corn straw compost in soil.

8. The detection method for application of straw compost in rice planting as claimed in claim 4, characterized in that: The total flavonoids and total phenolic contents in rice leaves were positively correlated with the proportion of corn straw compost in the soil.

Images