Application of Nano-Mn3O4 in Alleviating Salt Stress in Vegetables and / or Increasing Flavonoid Content in Vegetables
By preparing and spraying nano-Mn3O4 solution with manganese acetate tetrahydrate as the manganese source, the effects of salt stress on vegetable growth and flavonoid content were solved, growth improvement and increased flavonoid content were achieved, providing an environmentally friendly solution.
Patent Information
- Application Number
- CN202411669472.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2044-11-21
AI Technical Summary
The effects of salt stress on vegetable growth and flavonoid content lead to slow growth, leaf yellowing, reduced photosynthesis and obstructed nutrient supply, and there is a lack of effective mitigation methods.
Nano-Mn3O4 was prepared using manganese acetate tetrahydrate as the manganese source and sprayed on vegetable leaves. Nano-Mn3O4 solution was prepared through hydrothermal reaction with a concentration of 50-150 mg/L, which was used to alleviate salt stress and increase the content of flavonoids.
It significantly improves the growth of vegetables under salt stress, increases the content of flavonoids, enhances the nutritional and medicinal value of vegetables, and provides a simple, effective and environmentally friendly solution.
Smart Images
Figure CN119498349B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of vegetable planting, in particular to the application of nano-Mn3O4 in alleviating salt stress of vegetables and / or increasing the content of flavonoids in vegetables. Background Art
[0002] The formation of saline soil is usually due to the Na + and Cl - The accumulation of high concentrations of ions leads to high osmotic pressure and high ion conditions in the soil. This salinization phenomenon will have an adverse effect on the growth and development of vegetables. In a high-salt environment, the osmotic pressure of the soil increases, and the ability of vegetable roots to absorb water from the soil is severely hindered. At the same time, high concentrations of Na + and Cl - Ions can also interfere with the absorption of essential nutrients by vegetables, limiting their nutritional supply. Numerous studies have shown that salt stress affects vegetables in multiple ways. First, salt accumulation can lead to stunted growth and slow growth. Second, salt stress can thicken vegetable leaves and reduce chlorophyll content, leading to yellowing and ultimately leaf shedding. These changes directly impact the photosynthetic capacity of vegetables. Salt stress can also lead to excessive accumulation of reactive oxygen species (ROS), which not only affects the normal function of cell membranes and organelles but also inhibits photosynthesis and reduces the production of photosynthetic products. This reduced photosynthesis severely inhibits overall plant growth and development, ultimately resulting in poor vegetable growth performance and significantly reduced yield and quality. Therefore, the management and improvement of saline soils are crucial for protecting vegetable growth and increasing agricultural yields. However, there is currently a lack of vegetable protectants that mitigate the damage caused by salt stress. Summary of the Invention
[0003] To address the above issues, the present invention provides the use of nano-Mn3O4 to alleviate salt stress in vegetables and / or increase the flavonoid content in vegetables. The present invention has discovered that nano-Mn3O4 prepared using manganese acetate tetrahydrate as a manganese source can not only alleviate salt stress in vegetables but also increase the flavonoid content in vegetables, thereby enhancing their nutritional or medicinal value.
[0004] In order to achieve the above object, the present invention provides the following technical solutions:
[0005] The present invention provides the use of nano-Mn3O4 in alleviating salt stress of vegetables and / or increasing the content of flavonoids in vegetables. The manganese source for preparing the nano-Mn3O4 is manganese acetate tetrahydrate.
[0006] Preferably, the vegetables include: ice plant, broccoli or tomato.
[0007] Preferably, the preparation method of nano Mn3O4 includes:
[0008] dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution;
[0009] The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.
[0010] Preferably, the temperature of the hydrothermal reaction is 120° C. and the time is 24 hours.
[0011] Preferably, the lining material of the hydrothermal reaction device is polytetrafluoroethylene.
[0012] Preferably, the effective concentration of the nano-Mn3O4 is 50-150 mg / L.
[0013] The present invention provides a method for alleviating salt stress in vegetables and / or increasing the content of flavonoids in vegetables, comprising the following steps:
[0014] The nano-Mn3O4 solution is sprayed on vegetable leaves; the manganese source for preparing the nano-Mn3O4 solution is manganese acetate tetrahydrate.
[0015] Preferably, the concentration of nano-Mn3O4 in the nano-Mn3O4 solution is 50-150 mg / L.
[0016] Preferably, the preparation method of nano Mn3O4 includes:
[0017] dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution;
[0018] The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.
[0019] Preferably, the vegetables include: ice plant, broccoli or tomato.
[0020] Beneficial effects:
[0021] The present invention provides the use of nano-Mn3O4 for alleviating salt stress in vegetables and / or increasing the flavonoid content in vegetables. The manganese source for preparing the nano-Mn3O4 is manganese acetate tetrahydrate. The present invention has discovered that nano-Mn3O4 prepared using manganese acetate tetrahydrate as the manganese source can not only alleviate salt stress in vegetables but also increase the flavonoid content in vegetables, thereby enhancing their nutritional value or medicinal value.
[0022] Furthermore, the present invention alleviates salt stress in vegetables and increases the content of flavonoids in the vegetables by spraying nano-Mn3O4 on the leaves of vegetables under salt stress. The method provided by the present invention improves vegetable physiological indicators, increases flavonoid content, and helps alleviate the effects of salt stress on vegetables. It is a simple, effective, and environmentally friendly method for alleviating salt stress in vegetables. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below.
[0024] Figure 1 The growth diagrams of ice plant, broccoli and tomato after salt stress and nano-Mn3O4 treatment;
[0025] Figure 2 Figure 2 shows the gene expression results of flavonoids in ice plant, broccoli, and tomato; (a) relative expression levels of key flavonoid genes in ice plant; (b) relative expression levels of key flavonoid genes in broccoli; (c) relative expression levels of key flavonoid genes in tomato; different lowercase letters indicate significant differences between different groups (P < 0.05);
[0026] Figure 3 Schematic diagram of the nanoparticles synthesized to provide a manganese source for manganese sulfate acting on three plants: ice plant, broccoli, and tomato. The treatment conditions from left to right are: 0mM NaCl, 200mM NaCl, 200mM NaCl + 100mg / LMn3O4 NPs;
[0027] Figure 4 This is a schematic diagram of the action of nanoparticles synthesized using potassium permanganate as a manganese source on three plants: ice plant, broccoli and tomato; the treatment conditions from left to right are: 0mM NaCl, 200mM NaCl, 200mM NaCl+100mg / LMn3O4 NPs. DETAILED DESCRIPTION
[0028] The present invention provides the use of nano-Mn3O4 in alleviating salt stress of vegetables and / or increasing the content of flavonoids in vegetables. The manganese source for preparing the nano-Mn3O4 is manganese acetate tetrahydrate.
[0029] The present invention finds that nano Mn3O4 synthesized with manganese acetate tetrahydrate as a manganese source can significantly improve the growth of vegetables under salt stress.
[0030] The present invention found that under salt stress, the growth trends of vegetables sprayed with Mn3O4 nanosolutions differed visibly from those not sprayed. Furthermore, physiological indicators revealed that the Mn3O4 nanosolutions alleviated the damage caused by salt stress and increased the content of flavonoids in the vegetables. This method of spraying the Mn3O4 nanosolutions on the leaves of vegetables under salt stress is a simple, effective, and environmentally friendly method for alleviating salt stress in vegetables.
[0031] As an embodiment, the vegetables include: ice plant, broccoli or tomato.
[0032] As an embodiment, the preparation method of the nano Mn3O4 includes:
[0033] dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution;
[0034] The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.
[0035] As an embodiment, the mass volume ratio of the manganese acetate tetrahydrate and anhydrous ethanol is 1.225g:60mL.
[0036] As an embodiment, the temperature of the hydrothermal reaction is 120° C. and the time is 24 hours.
[0037] As an embodiment, the lining material of the hydrothermal reaction device is polytetrafluoroethylene.
[0038] In one embodiment, the effective concentration of the nano-Mn3O4 is 50 to 150 mg / L. In another embodiment, the effective concentration of the nano-Mn3O4 is 100 mg / L.
[0039] Based on the above advantages, the present invention provides a method for alleviating salt stress in vegetables and / or increasing the content of flavonoids in vegetables, comprising the following steps:
[0040] The nano-Mn3O4 solution is sprayed on vegetable leaves; the manganese source for preparing the nano-Mn3O4 solution is manganese acetate tetrahydrate.
[0041] In one embodiment, the concentration of nano-Mn3O4 in the nano-Mn3O4 solution is 50-150 mg / L. In another embodiment, the concentration of nano-Mn3O4 in the nano-Mn3O4 solution is 100 mg / L.
[0042] As an embodiment, the preparation method of nano Mn3O4 includes:
[0043] dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution;
[0044] The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.
[0045] As an embodiment, the temperature of the hydrothermal reaction is 120° C. and the time is 24 hours.
[0046] As an embodiment, the lining material of the hydrothermal reaction device is polytetrafluoroethylene.
[0047] As an embodiment, the vegetables include: ice plant, broccoli or tomato
[0048] To further illustrate the present invention, the application of nano-Mn3O4 provided by the present invention in alleviating vegetable salt stress and / or increasing the content of vegetable flavonoids is described in detail below with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.
[0049] Example 1 Spraying Nano-Mn3O4 to Alleviate Salt Stress on Vegetables
[0050] Step 1: Preparation of nano-Mn3O4 (Mn3O4 NPs). Dissolve 1.225g of manganese acetate tetrahydrate in 60mL of anhydrous ethanol and transfer to a 100mL reactor. Hydrothermally react at 120°C for 24 hours. The reactor is lined with high-temperature and corrosion-resistant polytetrafluoroethylene. After cooling, centrifuge to remove impurities, rinse three times with water, and dry in a drying oven overnight to obtain a brown powder, which is nano-Mn3O4 (Mn3O4 NPs).
[0051] Step 2: Preparation of nano-Mn3O4 solution: Weigh 50mg, 100mg, and 150mg of Mn3O4 NPs respectively, disperse them in 1000mL of distilled water under 180W ultrasonication at room temperature for 30min, and prepare nano-solutions of different concentrations for later use.
[0052] Step 3: Planting of vegetable materials. Select ice plant, broccoli and tomato seeds that are in good condition and of the same size, and place them in their respective culture dishes. A layer of filter paper soaked in water is laid in the culture dish to provide a suitable germination environment for the seeds. After 72 hours of cultivation, the seeds are sown in 16cm×16cm flower pots filled with a mixture of nutrient soil and vermiculite in a volume ratio of 2:1. Six flower pots are placed on each tray, and 2.5L of water is poured at a time to ensure that the soil is fully moistened, providing the necessary conditions for the growth of vegetables;
[0053] Step 4: After the ice plant and broccoli have grown two pairs of leaves and the tomato has reached the flowering stage, salt stress treatment is carried out. The ice plant, broccoli, and tomato vegetable samples are divided into 5 groups and treated as follows:
[0054] 0 mM NaCl treatment group: Pour 2.5 L of clean water into the tray. After the soil in the flowerpot is fully absorbed by the water, pour out the remaining water in the tray. The next day, spray the leaves with clean water to ensure that each leaf is evenly covered with clean water. This process is repeated twice a week.
[0055] 200mM NaCl treatment group: Pour 2.5L of 200mM NaCl into the tray. After the soil in the flowerpot is saturated with the salt water, pour out the remaining salt water in the tray. The next day, spray clean water on the leaves to ensure that each leaf is evenly covered with clean water. This is done twice a week.
[0056] 200mM NaCl + 50mg / L Mn3O4 NPs treatment group: Pour 2.5L of 200mM NaCl into the tray. After the soil in the flowerpot is saturated with the salt water, pour out the remaining salt water in the tray. The next day, spray the leaves with 50mg / L Mn3O4NPs solution to ensure that each leaf is evenly covered with Mn3O4NPs solution, twice a week.
[0057] 200mM NaCl + 100mg / L Mn3O4 NPs treatment group: Pour 2.5L of 200mM NaCl into the tray. After the soil in the flowerpot absorbs the salt water, pour out the remaining salt water in the tray. The next day, spray the leaves with 100mg / L Mn3O4 NPs solution to ensure that each leaf is evenly covered with Mn3O4 NPs solution, twice a week.
[0058] 200mM NaCl + 150mg / L Mn3O4 NPs treatment group: Pour 2.5L of 200mM NaCl into the tray. After the soil in the flowerpot is saturated with the salt water, pour out the remaining salt water in the tray. The next day, spray the leaves with 150mg / L Mn3O4 NPs solution to ensure that each leaf is evenly covered with Mn3O4 NPs solution, twice a week.
[0059] There were 6 pots in each group, and irrigation and foliar spraying of the corresponding solution were carried out regularly every week.
[0060] Step 5: After four weeks of salt and nanomaterial treatment, photosynthetic and physiological indicators of the three vegetables were measured (results are shown in Tables 2-9). A photosynthetic meter was used to measure the photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO₂ concentration of the three vegetables. A vegetable nutrient analyzer was used to measure leaf chlorophyll and nitrogen content. Malondialdehyde content was measured using the thiobarbituric acid method, proline content was measured using the acid ninhydrin method, superoxide dismutase (SOD) activity was measured using the nitroblue tetrazolium photoreduction method, peroxidase (POD) activity was measured using the guaiacol method, and catalase (CAT) activity was measured by the decomposition of hydrogen peroxide into water and oxygen. A vegetable flavonoid content kit was used to measure flavonoid content, and a hydrogen peroxide content kit was used to measure H₂O₂ content.
[0061] Step 6: Download the gene sequences related to vegetable flavonoids from the National Center for Biotechnology Information (NCBI) and design qPCR primers using Primer software. The primer sequences are shown in Table 1. Extract leaf RNA using the RNAprep Pure Vegetable Total RNA Extraction Kit, reverse transcribe the extracted RNA into cDNA using the FastKing cDNA First-Strand Synthesis Kit, and perform qPCR using the SuperReal Fluorescence Quantitation Premix Enhanced (SYBR Green) Kit.
[0062] Table 1 Primer sequences required for qPCR
[0063]
[0064]
[0065] Results and analysis:
[0066] Figure 1 The following are schematic diagrams of the growth of ice vegetable, broccoli and tomato after treatment with 200mM NaCl solution and different concentrations of Mn3O4 nano solutions, respectively. The concentrations of Mn3O4 in the figure are 50mg / L, 100mg / L and 150mg / L, respectively. It can be seen from the figure that compared with the water treatment group, 200mM NaCl has a stress effect on the growth of vegetables that can be discerned by the naked eye. The ice vegetable, broccoli and tomato plants are weak, and the tomato fruits are small and the yield is low. After spraying the nano solution, the stress effect is significantly alleviated. When the concentration of Mn3O4 is 100mg / L, the vegetable crops grow best. Therefore, 100mg / L is the optimal Mn3O4 concentration for spraying on the vegetable leaves.
[0067] Figure 2 Figure 2 shows the expression of flavonoid genes in iceberg lettuce, broccoli, and tomatoes. qPCR results indicate that the 200 mM NaCl treatment resulted in lower flavonoid gene expression in the three vegetables compared to the 0 mM NaCl treatment. The group sprayed with 100 mg / L Mn3O4 nanosolution exhibited higher gene expression than the 200 mM NaCl treatment. Therefore, salt stress reduces flavonoid gene expression in vegetables, leading to a decrease in flavonoid content. Flavonoids are a group of natural polyphenols with diverse biological activities, including antioxidant, antibacterial, and anti-inflammatory properties. Spraying 100 mg / L Mn3O4 nanosolution on vegetables under salt stress increased flavonoid gene expression, suggesting an increase in flavonoid content. This is consistent with and mutually reinforces the results for flavonoid content in vegetables in Tables 3, 6, and 8.
[0068] Net photosynthetic efficiency and stomatal conductance are both photosynthetic indicators of plant growth. Under salt stress, plant photosynthetic efficiency should decrease; nitrogen content reflects the plant's absorption of substances in the soil, and salt stress will hinder the plant's intake of nutrients; malondialdehyde is a marker of oxidative stress. When plants are subjected to salt stress, oxidative stress occurs and a large amount of reactive oxygen is produced, and the malondialdehyde content also increases accordingly; proline is an osmotic regulating substance in plants that helps cells maintain water balance.
[0069] When plants are exposed to salt stress, oxidative stress occurs, producing large amounts of reactive oxygen species. Antioxidant enzymes increase their activity to eliminate excess reactive oxygen species, returning to normal levels when the stress is relieved. H2O2 levels are one of the reactive oxygen species that accumulate excessively under salt stress, with levels significantly increasing when plants are exposed to salt stress and decreasing when the stress is relieved.
[0070] Soluble proteins are involved in a variety of functions, including cellular metabolism, osmotic regulation, signal transduction, and stress resistance. Salt-tolerant plants can respond to salt stress by increasing their soluble protein content. Intercellular CO2 concentration, stomatal conductance, transpiration rate, and net photosynthetic efficiency are all indicators of plant photosynthesis, and plant photosynthetic efficiency should decrease under salt stress. H2O2 content, one of the reactive oxygen species that accumulates excessively under salt stress, increases significantly when plants are exposed to salt stress and decreases after the stress is alleviated.
[0071] As shown in Tables 2 to 9, physiological indicators such as leaf wet weight, leaf dry weight, root dry weight, leaf area, chlorophyll content, antioxidant enzymes, malondialdehyde content, proline content, and flavonoid content all demonstrate the stress effects of salinity on plant growth. These indicators were significantly alleviated after spraying the Mn3O4 NPs solution, with significant differences between treatment groups. This indicates that spraying the Mn3O4 NPs solution prepared in the present invention can alleviate the effects of salt stress on physiological indicators such as malondialdehyde content, proline content, and flavonoid content in vegetables.
[0072] Table 2 Physiological indicators of ice plant
[0073]
[0074] Note: 1 is the 0 mM NaCl treatment group, 2 is the 200 mM NaCl treatment group, 3 is the 200 mM NaCl and 100 mg / L mn3O4 NPs treatment group, different lowercase letters represent significant differences between different groups (P < 0.05), the same applies to the following table.
[0075] Table 3 Physiological indicators of ice plant
[0076]
[0077] Table 4 Physiological indicators of ice plant
[0078]
[0079] Table 5 Physiological indicators of broccoli
[0080]
[0081] Table 6 Physiological indicators of broccoli
[0082]
[0083] Table 7 Physiological indicators of broccoli
[0084]
[0085] Table 8 Physiological indicators of tomato
[0086]
[0087] Table 9 Physiological indicators of tomato
[0088]
[0089] Comparative Example 1
[0090] Manganese sulfate was used as a manganese source to react with sodium bicarbonate to form a precipitate, which was then calcined to synthesize Mn3O4NPs as follows:
[0091] Prepare 0.1M manganese nitrate in distilled water and stir until the temperature reaches 90°C. Then, add 0.05M sodium bicarbonate dropwise to raise the pH to 9. Stop adding sodium bicarbonate and continue heating and stirring for 3 hours. Cool to room temperature and stir overnight. Wash the reaction mixture by centrifugation and dry at 70°C overnight. Then, calcine the resulting reaction mixture at 600°C for 12 hours to obtain nano-Mn3O4.
[0092] Comparative Example 2
[0093] Mn3O4NPs were synthesized by hydrothermal reaction of potassium permanganate and glucose in a reactor as follows:
[0094] Weigh 0.2376g of potassium permanganate and 0.585g of glucose, dissolve them in 80mL of deionized water, transfer them to a polytetrafluoroethylene autoclave, adjust the solution to alkalinity with sodium hydroxide, and react at 120°C for 24 hours. The reaction product is centrifuged, washed, and dried in a vacuum oven at 80°C to obtain nano-Mn3O4.
[0095] Using a similar method to Example 1, three treatment groups were set up: 0mM NaCl, 200mM NaCl, 200mM NaCl + 100mg / L Mn3O4 NPs. The nano Mn3O4 prepared in Comparative Examples 1 and 2 was sprayed on ice plant, broccoli and tomato respectively. The results are shown in Table 1. Figure 3 and Figure 4 .
[0096] Depend on Figure 3 and Figure 4 It can be seen that when nano Mn3O4 prepared using manganese sulfate or potassium permanganate as the manganese source is sprayed on the leaves of salt-stressed plants, there is no obvious effect of alleviating salt stress. However, the nanoparticles synthesized using manganese acetate as the manganese source in Example 1 of the present invention can alleviate the effect of salt stress on plants.
[0097] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.
Claims
1. Application of nano-Mn3O4 in alleviating salt stress in vegetables and / or increasing the content of flavonoids in vegetables, wherein the manganese source for preparing the nano-Mn3O4 is manganese acetate tetrahydrate; the effective concentration of the nano-Mn3O4 is 50-150 mg / L; and the vegetables are: iceberg lettuce, broccoli, or tomatoes; The preparation method of the nano-Mn3O4 comprises: dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution; The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.
2. The use according to claim 1, characterized in that The temperature of the hydrothermal reaction is 120° C. and the time is 24 hours.
3. The use according to claim 1 or 2, characterized in that The lining material of the hydrothermal reaction device is polytetrafluoroethylene.
4. A method for alleviating salt stress in vegetables and / or increasing the content of flavonoids in vegetables, characterized in that: The following steps are involved: The nano-Mn3O4 solution is sprayed on the leaves of vegetables; the manganese source for preparing the nano-Mn3O4 solution is manganese acetate tetrahydrate; the concentration of nano-Mn3O4 in the nano-Mn3O4 solution is 50-150 mg / L; the vegetables are: iceberg lettuce, broccoli or tomatoes; The preparation method of the nano-Mn3O4 comprises: dissolving manganese acetate tetrahydrate in anhydrous ethanol to obtain a mixed solution; The mixed solution is subjected to a hydrothermal reaction to obtain the nano-Mn3O4.