Method for promoting cadmium enrichment of plants by using molybdenum trioxide
By applying molybdenum trioxide nanoparticles in cadmium-contaminated soil, the growth and cadmium enrichment of alanum are promoted, and the problems of large doses of application and slow plant growth in the prior art are solved, and efficient cadmium enrichment and soil repair are achieved.
Patent Information
- Application Number
- CN202510118736.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art has defects such as large doses of application, slow plant growth, and poor plant tolerance in the repair of heavy metal contaminated soil, making it difficult to achieve efficient cadmium enrichment and soil repair.
Molybdenum trioxide promotes cadmium enrichment in plants, and the planting of cadmium sunflower is achieved by applying molybdenum trioxide nanoparticles in cadmium-contaminated soil.
The nutrient extraction efficiency and photosynthesis efficiency of Longan Sunflower have been significantly improved, the plant's ability to enrich cadmium, and the excessive enrichment of cadmium in high-concentration cadmium polluted soils has been achieved, while there is no negative impact on the soil ecological environment.
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Figure CN120094966A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of heavy metal contaminated soil remediation, and specifically relates to a method for promoting plant cadmium enrichment by using molybdenum trioxide. Background Art
[0002] In recent years, the increasingly serious soil cadmium pollution has become one of the main problems threatening environmental ecological security. Due to its high toxicity, persistence and bioaccumulation, heavy metal cadmium (Cd, Cadmium) will have a negative impact on plants, animals and microorganisms in the soil ecosystem. Cadmium that enters plant or animal tissues can also accumulate in the human body through the food chain enrichment effect, thus posing a threat to human health. Phytoremediation technology is a low-cost, environmentally friendly method for the remediation of heavy metal-contaminated soil. Its principle is to transfer heavy metals into plants through plant extraction to achieve the removal of heavy metals in the soil. However, in the actual application of this technology, there are defects such as long plant growth cycle, environmental conditions, low remediation efficiency, and poor operability.
[0003] With the rapid development of nanotechnology, some researchers have applied nanomaterials to the field of heavy metal pollution remediation to assist plants in the remediation of heavy metal contaminated soil. However, the applicant found in the preliminary investigation that when the existing nanomaterial-plant system is used to remediate heavy metal contaminated soil, there are defects such as large application dosage of nanomaterials, slow plant growth, and poor plant tolerance. Therefore, how to obtain a method for promoting plant enrichment of cadmium with a small application amount, high plant growth rate, high cadmium enrichment content, and no negative impact on the soil ecological environment is of great significance for the remediation of high-concentration cadmium contaminated soil. Summary of the invention
[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for promoting plant cadmium enrichment by using molybdenum trioxide, which has the advantages of small application amount, high plant growth rate, high cadmium enrichment content and no negative impact on the soil ecological environment.
[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.
[0006] A method for promoting cadmium enrichment in plants by using molybdenum trioxide comprises the following steps: applying molybdenum trioxide to cadmium-contaminated soil, planting plants, and cultivating them to achieve cadmium enrichment in the plants; the plants are Solanum nigrum.
[0007] The above method is further improved in that the application amount of molybdenum trioxide is 2mg to 8mg per kilogram of cadmium-contaminated soil.
[0008] The above method is further improved in that the application amount of molybdenum trioxide is 4mg to 8mg per kilogram of cadmium-contaminated soil.
[0009] The above method is further improved in that the application amount of molybdenum trioxide is 4 mg per kilogram of cadmium-contaminated soil.
[0010] The above method is further improved in that the molybdenum trioxide is molybdenum trioxide nanoparticles.
[0011] The above method is further improved in that the concentration of cadmium in the cadmium-contaminated soil is 5 mg / kg to 20 mg / kg.
[0012] The above method is further improved in that the concentration of cadmium in the cadmium-contaminated soil is 9 mg / kg to 20 mg / kg.
[0013] The above method is further improved, wherein the cultivation time is ≥ 60 days; the specific process of the cultivation is: under the conditions of a temperature of 25°C and a relative humidity of 80%, 12 hours of light and 12 hours of darkness, repeated cycles, simulating the light and dark cycle of plants growing in nature.
[0014] The above method is further improved, wherein the Solanum nigrum further comprises the following treatments before planting: sterilizing and accelerating germination of Solanum nigrum seeds.
[0015] The above method is further improved, wherein the specific process of the disinfection is: placing the Solanum nigrum seeds in a sodium hypochlorite solution for disinfection for 10 minutes to 15 minutes; the mass fraction of the sodium hypochlorite solution is 10%; the specific process of the germination is: in dark conditions, the disinfected Solanum nigrum seeds are germinated at 25° C.; the germination time is ≥7 days.
[0016] Compared with the prior art, the advantages of the present invention are:
[0017] The present invention discloses a method for promoting plant enrichment of cadmium by molybdenum trioxide, by constructing a molybdenum trioxide-sunflower-cadmium polluted soil ecological system, synchronously improving the growth efficiency and cadmium enrichment ability of nightshade plants, and realizing the large-scale enrichment of cadmium in high-concentration cadmium polluted soil by nightshade. Specifically, after applying molybdenum trioxide, on the one hand, as a trace nutrient supplement for nightshade plants, it can promote the activation of trace elements in rhizosphere soil, which is beneficial to the nutrient absorption of plants, significantly improves the nutrient extraction efficiency and photosynthesis efficiency of nightshade, and at the same time alleviates the oxidative stress caused by heavy metal cadmium, improves the growth inhibition of nightshade plants under cadmium stress, thereby promoting the growth and development of nightshade plants in high-concentration cadmium polluted soil; on the other hand, as a stimulant for nightshade plants, it can promote the activation of cadmium elements in rhizosphere soil, which is beneficial to the enrichment of cadmium by nightshade plants, and at the same time enhances the ability of nightshade plant tissues to enrich cadmium, and finally realizes the super enrichment of cadmium in high-concentration cadmium polluted soil by nightshade. The method of the present invention has the advantages of small application amount, high plant growth rate, high cadmium enrichment content, and no negative impact on soil ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a scanning electron microscope image of the molybdenum trioxide nanoparticles in Example 1 of the present invention.
[0019] Figure 2 This is an energy scattering spectrum of molybdenum trioxide nanoparticles in Example 1 of the present invention.
[0020] Figure 3 This is a graph showing the effects of different treatments in Example 1 of the present invention on the root / stem length and fresh biomass of Solanum nigrum under cadmium stress.
[0021] Figure 4 This is a graph showing the effects of different treatments in Example 1 of the present invention on the chlorophyll content of Solanum nigrum leaves under cadmium stress.
[0022] Figure 5 This is a graph showing changes in hydrogen peroxide content in the roots and seedlings of Solanum nigrum under cadmium stress in different treatments in Example 1 of the present invention.
[0023] Figure 6 This is a graph showing changes in malondialdehyde content in the roots and seedlings of Solanum nigrum under cadmium stress in different treatments in Example 1 of the present invention.
[0024] Figure 7 This is a graph showing changes in DTPA-extractable cadmium content in rhizosphere soil and non-rhizosphere soil of Solanum nigrum under different treatments in Example 1 of the present invention.
[0025] Figure 8 This is a graph showing changes in cadmium accumulation content in Solanum nigrum tissues under cadmium stress under different treatment methods in Example 1 of the present invention.
[0026] Fig. 9 This is a graph showing the urease activity of Solanum nigrum rhizosphere soil and non-rhizosphere soil under different treatments in Example 1 of the present invention.
[0027] Fig.10 This is a graph showing the phosphatase activity of Solanum nigrum rhizosphere soil and non-rhizosphere soil under different treatments in Example 1 of the present invention.
[0028] Fig.11 This is a principal coordinate analysis diagram of the overall distribution of microbial communities in the rhizosphere soil of Solanum nigrum under different treatment methods in Example 1 of the present invention.
[0029] Fig.12 This is a relative abundance diagram of the microbial community structure at the phylum level in the rhizosphere soil of Solanum nigrum under different treatment methods in Example 1 of the present invention. DETAILED DESCRIPTION
[0030] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.
[0031] Embodiment 1:
[0032] A method for promoting cadmium enrichment in plants by using molybdenum trioxide of the present invention comprises the following steps:
[0033] S1. Select soil, molybdenum trioxide nanoparticles, and Solanum nigrum seeds
[0034] Uncontaminated farmland soil (total cadmium content of 0.06 mg / kg) was collected, and laboratory cadmium exposure and stabilization treatment were carried out to obtain cadmium-contaminated soil; the properties of the cadmium-contaminated soil are as follows: organic matter content is 6.5 g / kg, total nitrogen content is 0.90 g / kg, total phosphorus content is 688.79 mg / kg, and total cadmium content is 9.89 mg / kg. Molybdenum trioxide nanoparticles were purchased from Zhenhan New Materials (Suzhou) Co., Ltd., with the item number YT-MoO3-T01. Solanum nigrum seeds were purchased from Shandong Shouhe Seed Co., Ltd., China, and the following treatments were performed before use: Solanum nigrum seeds were placed in a sodium hypochlorite solution (the mass fraction of the solution was 10%) for disinfection for 10 minutes, washed with ultrapure water, placed in a culture dish in the dark, 25°C conditions for germination for one week, and Solanum nigrum seedlings with the same growth were selected for soil transplantation.
[0035] S2. Experimental treatment
[0036] According to the application amount of molybdenum trioxide nanoparticles of 2mg / kg, 4mg / kg, and 8mg / kg (i.e., the amount of molybdenum trioxide applied per kilogram of cadmium-contaminated soil), the molybdenum trioxide nanoparticles in step S1 are applied to the cadmium-contaminated soil, and Solanum nigrum seedlings are planted for plant cultivation. The cultivation conditions are: 12 hours of light and 12 hours of darkness at a temperature of 25°C and a relative humidity of 80%, alternating and repeated cycles to simulate the light and dark cycle of plant growth in nature; cultivate for two months (60 days). Among them, when the application amount of molybdenum trioxide nanoparticles is 2mg / kg, 4mg / kg, and 8mg / kg, they are recorded as Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8. After the cultivation cycle, the growth efficiency, cadmium enrichment ability, and in vivo antioxidant system expression of the plant Solanum nigrum are tested to evaluate the efficiency of plant restoration, and the bioavailability of cadmium and micronutrients in the soil, enzyme activity, and microbial community structure are characterized to evaluate the potential impact of nanomaterial application on soil habitats.
[0037] Control group 1 (CK): No molybdenum trioxide nanoparticles were applied, and uncontaminated farmland soil was used as the experimental soil (total cadmium content was 0.06 mg / kg), and other conditions were the same.
[0038] Control group 2 (Cd): no molybdenum trioxide nanoparticles were administered, and other conditions were the same.
[0039] Figure 1 This is a scanning electron microscope image of the molybdenum trioxide nanoparticles in Example 1 of the present invention. Figure 2 This is an energy scattering spectrum of molybdenum trioxide nanoparticles in Example 1 of the present invention. Figure 1 , Figure 2 It can be seen that the particle size distribution of molybdenum trioxide nanoparticles ranges from tens of nanometers to two hundred nanometers, with an average particle size of 99.83 nanometers. It is composed of molybdenum and oxygen elements with a purity of 99%.
[0040] The plant tissues in each group were harvested and divided into different parts according to the above-ground and underground parts, and the rhizome length and fresh biomass were measured and recorded. Figure 3 As shown; take fresh leaves to determine the content of photosynthetic pigments, such as Figure 4 As shown; the concentrations of hydrogen peroxide and malondialdehyde were measured in the root and stem tissues of the plants to evaluate the oxidative stress level of the plant tissues, as shown Figure 5 As shown; for the determination of trace element content in plant tissues, concentrated nitric acid and 30% hydrogen peroxide were used for hot plate digestion in a ratio of 2:1 (volume ratio). After complete digestion, the content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS), as shown in Table 1.
[0041] After the plant cultivation was completed, the molybdenum and trace elements in the root and seedling tissues of Solanum nigrum in different treatment groups were tested, as shown in Table 1.
[0042] Table 1 Molybdenum and trace element contents in root and seedling tissues of Solanum nigrum under different treatments
[0043]
[0044] As can be seen from Table 1, after the application of molybdenum trioxide nanoparticles, the molybdenum content in Solanum nigrum was significantly increased, thereby promoting the growth and development of Solanum nigrum; at the same time, molybdenum trioxide nanoparticles can also promote Solanum nigrum to absorb trace elements from cadmium-contaminated soil, improve the absorption efficiency of trace elements in Solanum nigrum, and further promote the growth and development of Solanum nigrum.
[0045] Figure 3 This is a graph showing the effects of different treatments on the root / stem length and fresh biomass of Solanum nigrum under cadmium stress in Example 1 of the present invention. Figure 3It can be seen that compared with the CK group, the growth of Solanum nigrum plants under cadmium stress in the Cd group was significantly inhibited; after adding molybdenum trioxide nanoparticles, the root and stem length and biomass of Solanum nigrum plants in the Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups increased significantly, that is, molybdenum trioxide nanoparticles have a significant promoting effect on the growth of Solanum nigrum under cadmium stress. When the application amount of molybdenum trioxide nanoparticles is 4 mg / kg, its promoting effect on the growth and development of Solanum nigrum is most significant; when the application amount of molybdenum trioxide nanoparticles continues to increase to 8 mg / kg, the root and stem length and biomass of Solanum nigrum show a downward trend, that is, excessive molybdenum trioxide nanoparticles have a potential adverse effect on the growth of Solanum nigrum plants.
[0046] Figure 4 This is a graph showing the effects of different treatment methods on the chlorophyll content of Solanum nigrum leaves under cadmium stress in Example 1 of the present invention. Figure 4 It can be seen that when the application amount of molybdenum trioxide nanoparticles is 4 mg / kg, the chlorophyll content of Solanum nigrum is the highest. As a major participant in photosynthesis efficiency, chlorophyll content plays an important role in plant photosynthesis efficiency. The molybdenum trioxide nanoparticles applied by the present invention provide molybdenum elements for chlorophyll synthesis in Solanum nigrum leaves, which can improve plant photosynthesis efficiency and promote the growth and development of Solanum nigrum plants.
[0047] Figure 5 This is a graph showing changes in hydrogen peroxide content in the roots and seedlings of Solanum nigrum under cadmium stress in different treatments in Example 1 of the present invention. Figure 6 The following is a graph showing the changes in malondialdehyde content in the roots and seedlings of Solanum nigrum under cadmium stress under different treatments in Example 1 of the present invention. Figure 5 , Figure 6 It can be seen that compared with the CK group, the contents of malondialdehyde and hydrogen peroxide in the tissues of Solanum nigrum in the Cd group increased significantly under cadmium stress, that is, Solanum nigrum was subjected to obvious oxidative stress; and after the application of molybdenum trioxide nanoparticles, the oxidative stress of the root and stem tissues of Solanum nigrum in the Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups was significantly alleviated. For the oxidative stress level of Solanum nigrum roots, when the application amount of molybdenum trioxide nanoparticles was 4 mg / kg, the oxidative stress relief effect on the root tissue was the most obvious; for the oxidative stress level of Solanum nigrum stems, with the increase in the application amount of molybdenum trioxide nanoparticles, the oxidative stress pressure on the stem tissue also gradually increased. When the application amount of molybdenum trioxide nanoparticles was 8 mg / kg, the oxidative stress relief effect on the stem tissue was relatively limited, that is, excessive molybdenum trioxide nanoparticles would instead have a stress effect on the growth of Solanum nigrum.
[0048] The above results show that the application of molybdenum trioxide nanoparticles in cadmium-contaminated soil can serve as a trace nutrient supplement and stimulant for Solanum nigrum plants, significantly improving the nutrient extraction efficiency and photosynthesis efficiency of Solanum nigrum, alleviating the oxidative stress caused by heavy metal cadmium, and thus promoting the growth and development of Solanum nigrum plants in cadmium-contaminated soil.
[0049] After the cultivation period, the bioavailable cadmium content in the soil and the cadmium accumulation content in different parts of the plant were measured to evaluate the effect of molybdenum trioxide nanoparticles on the efficiency of Solanum nigrum in repairing cadmium-contaminated soil. Specifically, the rhizosphere and non-rhizosphere soils after the plant cultivation experiment were taken, 2 g of soil samples were weighed, and a metal element chelator was used as an extractant. The DTPA concentration in the extractant was 0.005 M, the triethanolamine concentration was 0.1 M, and the calcium chloride concentration was 0.01 M. The pH of the extractant was 7.3, and the culture was shaken at 25 ° C and 150 rpm for 2 hours; the supernatant was centrifuged and the metal content was determined by ICP-MS.
[0050] Figure 7 The graph is a graph showing the changes in DTPA-extractable cadmium content in rhizosphere soil and non-rhizosphere soil of Solanum nigrum under different treatment methods in Example 1 of the present invention. Figure 7 It can be seen that compared with the Cd group, after the application of molybdenum trioxide nanoparticles, the content of DTPA-extractable cadmium in the rhizosphere and non-rhizosphere soils of the Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups was significantly increased, and gradually increased with the increase in the application amount. That is to say, the application of molybdenum trioxide nanoparticles can promote the conversion of cadmium in the soil into bioavailable cadmium, thereby improving the cadmium enrichment efficiency of Solanum nigrum.
[0051] Figure 8 This is a graph showing the changes in cadmium accumulation in Solanum nigrum tissues under cadmium stress in different treatment methods in Example 1 of the present invention. Figure 8 It can be seen that compared with the Cd group, after the application of molybdenum trioxide nanoparticles, the cadmium content in the root and seedling tissues of Solanum nigrum plants in the Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups increased significantly, and gradually increased with the increase in the application amount, showing a dose effect, that is, molybdenum trioxide nanoparticles have a significant promoting effect on the enrichment of cadmium in Solanum nigrum. For Solanum nigrum root tissue, when the application amount of molybdenum trioxide nanoparticles is 4 mg / kg, the cadmium content in the root tissue is the highest, reaching 115.67 mg / kg; and with the increase in the application amount of molybdenum trioxide nanoparticles, the cadmium content in the root tissue of Solanum nigrum showed a downward trend due to the tolerance of plant tissues. For Solanum nigrum seedling tissue, that is, the aboveground part of the Solanum nigrum plant, its cadmium content increases with the increase in the application amount of molybdenum trioxide nanoparticles.
[0052] The above results show that the application of molybdenum trioxide nanoparticles in high-concentration cadmium-contaminated soil can simultaneously improve the growth efficiency and cadmium enrichment ability of Solanum nigrum plants, thereby promoting the enrichment of cadmium in cadmium-contaminated soil by Solanum nigrum. Specifically, on the one hand, molybdenum trioxide nanoparticles can improve the growth inhibition of Solanum nigrum plants under cadmium stress and promote the growth of Solanum nigrum plants; on the other hand, molybdenum trioxide nanoparticles, as stimulants, can enhance the ability of Solanum nigrum plant tissues to enrich cadmium.
[0053] In order to further verify the impact of molybdenum trioxide nanoparticles on soil habitats and evaluate their safety and feasibility in the actual remediation process, the soil microbial community was measured after the incubation period. At the end of the incubation period, the rhizosphere and non-rhizosphere soils of the CK group, Cd group, Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups were sampled for nutrient cycle-related enzyme activities and microbial 16S rRNA sequencing analysis. For enzyme activity determination, we characterized urease and alkaline phosphatase related to soil nitrogen and phosphorus cycles. The results are shown in Fig. 9 , Fig.10 The method for determining urease is based on the indigo blue colorimetric method: using 10% urea solution as the matrix, incubating at 37°C for 24 hours in a citric acid buffer (pH 6.7); taking the filtrate, adding ultrapure water, sodium phenol and sodium hypochlorite solution for color development, and measuring the absorbance at a wavelength of 578nm; combining the standard curve drawing method to calculate the enzyme activity, the unit is: NH 4+ -N mg / (gh). The alkaline phosphatase determination method is carried out by spectrophotometry: using 0.5% disodium phenyl phosphate as the matrix, incubating at 37°C for 24 hours under borate buffer (pH 9); adding 100 mL of 0.3% aluminum sulfate solution and filtering, adding acetate buffer and chlorodibromobenzoquinoneimine reagent for color development, and measuring the absorbance value at a wavelength of 660 nm; combining the standard curve drawing method to calculate the enzyme activity, the unit is: (mg / (kg h)).
[0054] Fig. 9 This is a graph showing the urease activity of Solanum nigrum rhizosphere soil and non-rhizosphere soil under different treatments in Example 1 of the present invention. Fig.10 Figure 1 is a graph showing the phosphatase activity of Solanum nigrum rhizosphere soil and non-rhizosphere soil under different treatments in Example 1 of the present invention. Fig. 9 , Fig.10It can be seen that compared with the CK group, the urease and alkaline phosphatase activities of the rhizosphere soil and non-rhizosphere soil of the Cd group under cadmium stress showed obvious inhibition, that is, heavy metal cadmium has an inhibitory effect on soil microbial activity. After the application of molybdenum trioxide nanoparticles, the urease activities of the rhizosphere soil and non-rhizosphere soil of the Cd-MoNP2, Cd-MoNP4, and Cd-MoNP8 groups were significantly improved, and the promotion effect on the urease activity of the rhizosphere soil was particularly significant. When the application amount of molybdenum trioxide nanoparticles increased from 2 mg / kg to 4 mg / kg, the activities of urease and alkaline phosphatase in the rhizosphere soil and non-rhizosphere soil increased significantly, and the urease and alkaline phosphatase in the rhizosphere soil showed the highest activity at 4 mg / kg; as the application amount of molybdenum trioxide nanoparticles increased to 8 mg / kg, the activities of urease and alkaline phosphatase in the rhizosphere soil and non-rhizosphere soil showed a downward trend. It can be seen that soil urease and alkaline phosphatase are important participants in the nitrogen and phosphorus cycles in the soil. Molybdenum trioxide nanoparticles have a significant promoting effect on the activity of soil urease and alkaline phosphatase under cadmium stress, especially the urease and alkaline phosphatase activity in the rhizosphere soil of Solanum nigrum, thereby accelerating the soil nutrient cycle process.
[0055] In order to explore the effects of molybdenum trioxide nanoparticle application on the disturbance and function of local soil microorganisms, the Cd-MoNP4 group was selected as a representative to sequence and analyze the rhizosphere soil microorganisms, as shown in Table 2, Fig.11 , Fig.12 As shown. The total DNA of the soil samples was extracted using a DNA Kit (Omega Bio-tek, Norcross, GA, US), and the concentration and purity of the obtained DNA were tested. The primer pair 341F: 5′-CCTACGGGNGGCWGCAG-3′, 805R: 5′-GACTACHVGGGTATCTAATCC-3′, was used to amplify the V3-V4 region of the bacterial 16SrRNA gene; each DNA was amplified by PCR three times. After microbial sequencing and subsequent offline data processing, the diversity, structural composition, and beneficial microbial functions of the soil microbial community under each treatment were analyzed.
[0056] Table 2 Species number and Alpha diversity index of rhizosphere soil microbial community under different treatments
[0057]
[0058] As can be seen from Table 2, heavy metal cadmium showed a significant inhibitory effect on the diversity of microorganisms and the number of species detected in the soil. Compared with the Cd group, after the application of molybdenum trioxide nanoparticles, the number of species, ACE index, and Chao1 index of the rhizosphere soil microbial community of Cd-MoNP4 increased significantly, indicating that molybdenum trioxide nanoparticles have a positive effect on the functionality and ecological health of rhizosphere soil microorganisms of Solanum nigrum under cadmium stress.
[0059] Fig.11 This is a principal coordinate analysis diagram of the overall distribution of microbial communities in the rhizosphere soil of Solanum nigrum under different treatment methods in Example 1 of the present invention. Fig.12 The relative abundance diagram of microbial community structure at the phylum level of Solanum nigrum rhizosphere soil under different treatment methods in Example 1 of the present invention. Fig.11 It can be seen that the intra-group aggregation and inter-group separation of the microbial communities in each treatment group are very good. Compared with the CK group, the microbial community structure in the cadmium-contaminated soil has changed significantly. The application of molybdenum trioxide nanoparticles has a certain mitigation effect on the microbial disturbance caused by cadmium on the PC1 axis (accounting for 32% of the explanation), which indicates that molybdenum trioxide nanoparticles have a certain restorative effect on the microbial community structure during the phytoremediation process of Solanum nigrum. Fig.12 It can be seen that the application of molybdenum trioxide nanoparticles promoted the increase in the relative abundance of microorganisms in the rhizosphere soil of Solanum nigrum that are beneficial to plant growth and related to nutrient cycling, such as Actinobacteriota, Verrucomicrobiota, Patescibacteria, Nitrospirota, etc. In other words, molybdenum trioxide nanoparticles can promote the growth and development of Solanum nigrum plants and the rhizosphere nutrient cycle process, improve the ability of Solanum nigrum to extract cadmium from high-concentration cadmium-contaminated soil, and ultimately achieve super-enrichment of cadmium in Solanum nigrum.
[0060] In summary, the method of promoting cadmium enrichment in plants by utilizing molybdenum trioxide of the present invention constructs a molybdenum trioxide-Solanum nigrum-cadmium contaminated soil ecological system, thereby simultaneously improving the growth efficiency and cadmium enrichment capacity of Solanum nigrum plants, improving the diversity of microbial communities in cadmium contaminated soil, and positively regulating the microbial community in the soil by increasing the relative abundance of microorganisms that are beneficial to plant growth and related to nutrient cycling, thereby improving the cadmium enrichment efficiency of Solanum nigrum plants under multi-dimensional synergistic effects, and ultimately achieving excessive enrichment of cadmium in high-concentration cadmium contaminated soil by Solanum nigrum.
[0061] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A method for promoting cadmium enrichment in plants using molybdenum trioxide, characterized in that: The following steps are involved: Molybdenum trioxide is applied to cadmium-contaminated soil, and plants are planted and cultivated to achieve cadmium enrichment in the plants; the plants are Solanum nigrum.
2. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 1, characterized in that: The application amount of the molybdenum trioxide is 2mg to 8mg per kilogram of cadmium-contaminated soil.
3. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 2, characterized in that: The application amount of the molybdenum trioxide is 4mg to 8mg per kilogram of cadmium-contaminated soil.
4. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 3, characterized in that: The application amount of the molybdenum trioxide is 4 mg per kilogram of cadmium-contaminated soil.
5. The method for promoting cadmium accumulation in plants using molybdenum trioxide according to any one of claims 1 to 4, characterized in that: The molybdenum trioxide is molybdenum trioxide nanoparticles.
6. The method for promoting cadmium accumulation in plants using molybdenum trioxide according to any one of claims 1 to 4, characterized in that: The concentration of cadmium in the cadmium-contaminated soil is 5 mg / kg to 20 mg / kg.
7. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 6, characterized in that: The concentration of cadmium in the cadmium-contaminated soil is 9 mg / kg to 20 mg / kg.
8. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 7, characterized in that: The cultivation time is ≥ 60 days; the specific process of the cultivation is: under the conditions of a temperature of 25° C. and a relative humidity of 80%, 12 hours of light and 12 hours of darkness, repeated cycles, simulating the light and dark cycle of plants growing in nature.
9. The method for promoting cadmium accumulation in plants using molybdenum trioxide according to any one of claims 1 to 4, characterized in that: The nightshade method also includes the following treatments before planting: sterilizing and accelerating germination of the nightshade seeds.
10. The method for promoting cadmium accumulation in plants by using molybdenum trioxide according to claim 9, characterized in that: The specific process of the disinfection is: placing the Solanum nigrum seeds in a sodium hypochlorite solution for disinfection for 10 to 15 minutes; the mass fraction of the sodium hypochlorite solution is 10%; the specific process of the germination is: in dark conditions, the disinfected Solanum nigrum seeds are germinated at 25°C; the germination time is ≥7 days.