Application of iron monatomic nano-enzyme in inhibition of Tilletia foetida or cultivation of wheat

Abstract

The invention discloses an application of an iron monatomic nano-enzyme in inhibition of Tilletia foetida or cultivation of wheat. According to the preparation method disclosed by the invention, Fe-SAzyme is synthesized by adopting a precursor calcination method. A plurality of influence antibacterial factors are optimized, and the obtained optimal antibacterial conditions are as follows: Tilletia foetida teliospore and an acidic buffer system containing Fe-SAzyme are co-incubated for 1 h, it is observed from a scanning electron microscope that the Tilletia foetida teliospore is deformed and broken, and the treated teliospore loses the germination ability after being inoculated to a culture medium. Tests show that the buffer system can catalyze and continuously generate three ROS (reactive oxygen species). In addition, experiments verify that Fe-SAzyme has no adverse effect on wheat seed germination and seedling growth. Therefore, the invention provides an innovative strategy for preventing and treating wheat tilletia foetida.

Description

Technical Field

[0001] The invention belongs to the field of wheat light stinking smut prevention and control, and relates to the application of iron single-atom nanozymes in inhibiting light stinking smut or cultivating wheat. Background Art

[0002] The problem of fungal infection has exacerbated the world food crisis, and fungal infection has caused a global loss of 10%-23% of food. Wheat light bunt is a worldwide fungal disease of wheat, which relies on the germination of the winter spores of the light bunt fungus to produce secondary basidiospores to infect seedlings. This winter spore has extremely strong vitality and tolerance, and usually can remain dormant for several years or even more than ten years. Although the use of chemical agents has effectively controlled wheat light bunt for a period of time, due to the development of organic agriculture and the enhancement of pathogen resistance, wheat light bunt has shown a trend of expanding infection areas worldwide. Therefore, how to scientifically, efficiently and safely prevent and control wheat light bunt is facing huge challenges.

[0003] Studies have shown that ROS (·OH, ·O2 – , 1 O2) can cause DNA mutations, change lipid metabolism, and induce bacterial death. The scientific community has found that many synthetic nanomaterials have the ability to release ROS and show significant bactericidal properties. Therefore, nanomaterials with high catalytic activity, that is, strong ability to catalyze substrates to produce ROS, are considered to be an effective means to combat drug-resistant bacteria. In recent years, single-atom nanozymes (SAzymes) have become a research frontier and hotspot in the field of catalysis due to their atomically dispersed metal active sites. The atomically dispersed active centers of SAzymes significantly improve the utilization rate of atoms and the density of active sites, while their coordination structure provides a clear explanation for the catalytic mechanism. Xu et al. synthesized monodisperse mesoporous carbon nanospheres at the Zn-N4 site. The material exhibited excellent peroxidase-like activity, was able to catalyze the decomposition of H2O2 to produce ·OH, effectively inhibited the growth of Pseudomonas aeruginosa, significantly promoted wound healing, and had high biosafety. Wang et al. prepared Cu SASs / NPC, which has peroxidase-like activity, glutathionease activity and photothermal properties. It can catalyze H2O2 to produce ·OH to kill bacteria, and absorb near-infrared light to increase the local temperature to kill bacteria, while enhancing the catalytic activity of the enzyme to produce more ·OH; Cu SASs / NPC also has GSH-Px activity, which consumes the GSH of bacteria, thereby significantly improving the bactericidal effect. The antibacterial research and application of these single-atom nanomaterials have opened up a new track for the prevention and control of light stinking smut. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide an application of an iron single-atom nanozyme in inhibiting light stinking smut or cultivating wheat. The iron single-atom nanozyme of the present invention can be used to prevent and control wheat light stinking smut.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: The present invention provides the application of iron single-atom nanozyme in inhibiting light smut fungus or cultivating wheat.

[0006] Wherein, the inhibition of T. tiliaceus is achieved by using the winter spores of T. tiliaceus.

[0007] Wherein, the cultivating wheat is applied in cultivating wheat germination or seedling growth.

[0008] The method for preparing the iron single-atom nanozyme comprises the following steps:

[0009] 1) Weigh Zn(NO3)2·6H2O, Fe(NO3)3·9H2O and CTAB and mix them to obtain a mixed metal salt;

[0010] 2) dissolving the mixed metal salt obtained in step 1) in deionized water to obtain a mixed metal salt solution;

[0011] 3) preparing a 2-methylimidazole solution having a mass percent concentration of 6.0-7.0%;

[0012] 4) adding the mixed metal salt solution prepared in step 2) to the 2-methylimidazole solution prepared in step 3), stirring vigorously for 10 min-30 min, and then standing at room temperature for 3 h-5 h;

[0013] 5) washing the product obtained in step 4) with an ethanol aqueous solution having a volume fraction of 40% to 70%, and vacuum drying to obtain a light yellow powder;

[0014] 6) The light yellow powder obtained in step 5) is placed in an alumina ark, and slowly heated to 900°C at a heating rate of 3°C / min-5°C / min in a tube furnace under Ar gas protection, and kept at 900°C for 2 hours. After taking out, it is naturally cooled to room temperature, and the product is collected and ground to obtain a black powder, which is an iron single-atom nanozyme.

[0015] Wherein, the concentrations of Zn(NO3)2·6H2O, Fe(NO3)3·9H2O and CTAB in step (2) are 1.9-2.1%, 0.06-0.07% and 0.09-0.1%, respectively.

[0016] Wherein, in the application, the concentration of iron single-atom nanozyme is 0.005-0.06 mg / mL.

[0017] Wherein, the application conditions include pH 3.5-5.5.

[0018] Wherein, the application conditions include a temperature of 20°C-37°C.

[0019] Wherein, the application conditions also include a H2O2 concentration of 4.85-29.1mM.

[0020] Wherein, the concentration of the teliospores of the light smut fungus is 10 4 ~10 7 Pieces / mL.

[0021] Invention mechanism: Through the specific experimental discovery of the present invention, see Figure 1 After the winter spores of Ustilago glabra are incubated in an acidic solution (pH 3.5-4.0) containing Fe-SAzyme, Fe-SAzyme exerts oxidase (OXD)-like catalytic activity, generates reactive oxygen species, destroys the winter spore structure, and causes the winter spore to lose its germination function. After the winter spores of Ustilago glabra are incubated in a buffer system (pH3.5-4.0+H2O2) containing Fe-SAzyme, Fe-SAzyme exerts oxidase (OXD)-like and peroxidase (POD)-like catalytic activity, generates strong reactive oxygen species, destroys the winter spore structure, and causes the winter spore to lose its germination function. After the winter spores of Ustilago farnesii are incubated in a buffer system containing Fe-SAzyme (pH 3.5-4.0+H2O2), Fe-SAzyme can exert oxidase (OXD) and peroxidase (POD)-like activities at room temperature (20°C), produce reactive oxygen, destroy the winter spore structure, and cause the winter spore to lose its germination function.

[0022] Beneficial effects: Compared with the prior art, the Fe-SAzyme prepared by the present invention provides a new strategy for the targeted prevention and control of wheat light stinking smut, and this prevention and control technology is safe, efficient, pollution-free and drug-free, and is expected to be widely used in agricultural growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the principle of destroying winter spores of Tilletia glabra by Fe-SAzyme prepared by the present invention.

[0024] Figure 2 It is a scanning electron microscope image of the Fe-SAzyme prepared by the present invention.

[0025] Figure 3 It is a diagram of the oxidase-like activity determination and condition optimization analysis of the Fe-SAzyme prepared by the present invention.

[0026] Figure 4It is a diagram of the peroxidase-like activity determination and condition optimization analysis of the Fe-SAzyme prepared by the present invention.

[0027] Figure 5 It is a diagram of the haloperoxidase activity determination and condition optimization analysis of the Fe-SAzyme prepared by the present invention.

[0028] Figure 6 It is the effect of Fe-SAzyme on the inhibition of teliospore germination in buffer systems with different pH conditions.

[0029] Figure 7 These are scanning electron microscope images of teliospores after incubation in different buffer systems.

[0030] Figure 8 It is the signal of hydroxyl radicals produced by Fe-SAzyme in different buffer systems determined by EPR.

[0031] Fig. 9 It is the signal of superoxide anion produced by Fe-SAzyme in different buffer systems determined by EPR.

[0032] Fig.10 It is the signal of singlet oxygen produced by Fe-SAzyme in different buffer systems determined by EPR.

[0033] Fig.11 This is a test of the effect of Fe-SAzyme on wheat seed germination and seedling growth. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the examples. It should be understood that the following examples are only intended to explain and illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0035] Example 1 Preparation and characterization of single-atom iron nanozyme

[0036] 1. Iron single-atom nanozymes were synthesized by precursor calcination method. Weigh 0.3626g Zn(NO3)2·6H2O, 0.01231g Fe(NO3)3·9H2O and 0.0175g CTAB, add them to 18mL deionized water, and sonicate to make them fully dissolved and rich in foam; weigh 5.6752g 2-methylimidazole, and dissolve it in 82mL deionized water; then quickly inject the mixed metal salt solution into the 2-methylimidazole solution, stir vigorously for 10min, and let it stand at room temperature (25℃) for 3h. The obtained product is washed several times with 50% ethanol aqueous solution and vacuum dried to obtain a light yellow powder; the light yellow powder is placed in an alumina ark, and then under Ar gas protection, slowly heated to 900℃ at a heating rate of 5℃ / min in a tube furnace, kept at 900℃ for 2h, taken out and naturally cooled to room temperature, the product is collected and ground to obtain a black powder, which is the iron single atom nanozyme (Fe-SAzyme).

[0037] 2. Material characterization: Scanning electron microscopy (SEM) was used to characterize the nanomaterials. Fe-SAzyme showed a complete hexahedral cubic structure, with uniform particle distribution and high size consistency. Figure 2 The material successfully maintained a relatively complete hexahedral framework structure without obvious structural collapse or particle aggregation (such as Figure 2 There are many micropores on the surface of the material, which are attributed to the volatilization of zinc at a high temperature of 650°C (as shown in the figure on the left). Figure 2 As shown in the right figure). Elemental mapping analysis confirmed the uniform distribution of carbon (C), nitrogen (N), and iron (Fe) in the nanocube morphology. Phase-corrected high-angle annular dark field scanning transmission electron microscopy (AC-HAADF-STEM) analysis showed that there were a large number of small bright spots in the image. These bright spots showed higher brightness in TEM imaging because the mass of iron atoms is significantly higher than that of light atoms such as carbon and nitrogen.

[0038] 3. Determination of three enzyme activities of iron single-atom nanozymes

[0039] 3.1) Determination of oxidase-like (OXD) activity of Fe-SAzyme

[0040] In exploring the OXD-like activity of Fe-SAzyme, TMB was used as an indicator, and the color change of TMB was used as an indicator to evaluate the catalytic activity. From the experiment, it can be seen that under the catalytic action of Fe-SAzyme, TMB is oxidized from a colorless state to blue ox-TMB, and the absorbance at a wavelength of 652nm will be significantly enhanced. In order to optimize the OXD-like activity of Fe-SAzyme, key experimental parameters such as the pH of the reaction buffer (0.2 mol / L acetic acid-sodium acetate buffer system, hereinafter referred to as the buffer), the concentration of Fe-SAzyme, the concentration of TMB, and the reaction temperature were investigated. From the experimental data, it can be seen that in the buffer system of pH 3.5, when the concentration of Fe-SAzyme is 0.02 mg / mL, the concentration of TMB is 0.03 mg / mL, and the reaction temperature is 37°C, Fe-SAzyme exhibits the best OXD-like enzyme activity, such as Figure 3 As shown. Calculate the oxidase activity of Fe-SAzyme. At this time, V max =4.61×10 -3 mM / s.

[0041] 3.2) Determination of peroxidase-like (POD) activity of Fe-SAzyme

[0042] By introducing H2O2, Fe-SAzyme and TMB into the buffer system, it was observed that the ·OH generated by the decomposition of H2O2 catalyzed by Fe-SAzyme could effectively oxidize TMB into blue ox-TMB. By monitoring the change in absorbance at a wavelength of 652nm, it was confirmed that the material had POD-like activity. In order to improve the enzyme activity, parameters such as the pH of the buffer, the concentration of Fe-SAzyme, the concentration of TMB, the concentration of H2O2 and the reaction temperature were optimized. After optimization experiments, it was found that in a buffer system of pH 4.0, when the concentration of Fe-SAzyme was 0.05mg / mL, the concentration of TMB was 0.03mg / mL, and the concentration of H2O2 was 14.55mM, at a reaction temperature of 37°C, Fe-SAzyme exhibited the best POD-like enzyme activity, such as Figure 4 As shown. Calculate the peroxidase activity of Fe-SAzyme. At this time, V max =1.41×10 -3 mM / s.

[0043] 3.3) Determination of haloperoxidase-like (HPO) activity of Fe-SAzyme

[0044] The HPO-like activity of nanomaterials refers to the ability of nanomaterials to simulate the function of halogen peroxidase in nature, which can catalyze the reaction between H2O2 and halogen molecules (such as chlorine Cl2 and bromine Br2), thereby achieving the oxidation or reduction of halogens. This type of activity is usually manifested in nanomaterials as highly efficient catalysis and significant selectivity for specific chemical reactions.

[0045] In the experiment, the HPO-like enzyme activity of Fe-SAzyme was tested and optimized. The optimal conditions for enzyme activity were obtained by optimizing the concentration of CB, H2O2, NaCl and reaction temperature. The experimental results show that when CB is 200μM, H2O2 is 19.4mM, NaCl is 0.4mM, and the reaction temperature is 37℃, the HPO-like enzyme activity of Fe-SAzyme is the best, as shown in 5. The halogen-peroxidase activity of Fe-SAzyme was calculated by recording the absorbance data. At this time, V max =3.38×10 -5 mM / s.

[0046] Example 2 Effect of Fe-SAzyme on the Inhibition of Winter Spore Germination of Tillandsia odorifera under Different pH Conditions

[0047] 1. To investigate the inhibitory effect on the germination of winter spores of Ustilago farfara under three different pH conditions. The following three pH buffer control groups were set up in the experiment: pH 3.5 buffer group, (pH 4.0 buffer + H2O2) group, (pH 5.8 buffer + H2O2 + NaCl) group; at the same time, three material treatment groups were established, namely: (pH 3.5 buffer + Fe-SAzyme) group, (pH 4.0 buffer + H2O2 + Fe-SAzyme) group, (pH 5.8 buffer + H2O2 + NaCl + Fe-SAzyme) group. The winter spores of Ustilago farfara were placed in these six different buffer systems and incubated for 2 hours, with the final concentration of winter spores being 10 6 The winter spores of light stinking smut are obtained by picking out the infected whole diseased wheat kernels from wheat infected with light stinking smut, which are called galls. Winter spores are extracted from the galls to make a winter spore suspension, and the concentration of winter spores is calculated by counting with a hemocytometer.

[0048] 2. After incubation, the teliospores were transferred to WA plates, and the germination and growth status of the six groups of teliospores were monitored in real time by microscopy. In the three control groups, it was observed that the teliospores began to germinate on the WA plates from the 5th day, and formed H bodies and secondary basidiospores by the 8th day. The secondary basidiospores were then transferred to PDA medium and cultured for 10 days. The formation of small white colonies was observed by the naked eye, such as Figure 6WA plate is a water agar plate, which is prepared by preparing agar powder into a 2% aqueous solution, sterilizing it under high temperature and high pressure conditions (121°C, 15min), and pouring the agar powder aqueous solution into a disposable sterile plate before solidification to prepare a water agar plate.

[0049] 3. Among the three material treatment groups, in the (pH 3.5 buffer + Fe-SAzyme) group and the (pH 4.0 buffer + H2O2 + Fe-SAzyme) group, the teliospores did not germinate on the 5th day of culture on the WA plate, and no H bodies or secondary basidiospores were formed on the 8th day. At the same time, deformation of the teliospores was observed; while in the (pH 5.8 buffer + H2O2 + NaCl + Fe-SAzyme) group, some teliospores germinated on the 5th day, and the germinated teliospores successfully formed H bodies and secondary basidiospores on the 8th day. After transfer on the 8th day and culture for 10 days, no colonies were observed on the PDA plates of the (pH 3.5 buffer + Fe-SAzyme) group and the (pH 4.0 buffer + H2O2 + Fe-SAzyme) group, while multiple small white colonies were generated on the PDA plate of the (pH 5.8 buffer + H2O2 + NaCl + Fe-SAzyme) group. like Figure 6 shown.

[0050] Example 3 Effect of H2O2 on the Inhibition of Tiliospore Germination of Tilium spores

[0051] 1. In view of the significant OXD-like and POD-like enzyme activities exhibited by Fe-SAzyme under pH 3.5 and 4.0 conditions, the effects of introducing H2O2 on the germination of winter spores of S. tiliaceus under these two specific pH conditions were compared. A total of eight groups were set up in the experiment, divided into four control groups and four experimental groups. The control groups were: pH 3.5 buffer control group, pH 4.0 buffer control group, (pH3.5 buffer + H2O2) control group, (pH 4.0 buffer + H2O2) control group; the four experimental groups included: (pH 3.5 buffer + Fe-SAzyme) group, (pH 4.0 buffer + Fe-SAzyme) group, (pH 3.5 buffer + H2O2 + Fe-SAzyme) group, (pH4.0 buffer + H2O2 + Fe-SAzyme) group. The volume of each group of solutions was 2mL, and the concentration of the group containing H2O2 was 20mM, and the final concentration of Fe-SAzyme was 20μg / mL. The winter spores of S. tiliaceus were placed in the eight different buffer systems and incubated in a biochemical incubator at 20°C for 2 h. The final concentration of winter spores was 10 6After incubation, 100 μL of the teliospore suspension was transferred to the agar plate, and then the agar plate was placed in a biochemical incubator for culture. The culture conditions were: temperature, 16°C, humidity, 60%, and normal light. All experimental groups were performed in triplicate.

[0052] 2. Transfer 100 μL of the winter spores of the eight groups of U. sutsugamushi to WA plates, and observe the germination of the winter spores under a microscope. The results of microscopic observation showed that on the 5th day, the winter spores of U. sutsugamushi in the four control groups had germinated to form promycelia, and further generated bundles of basidiospores. By the 8th day, the winter spores in the control groups all produced primary basidiospores, which fused with each other to form H bodies (germination and growth process of winter spores of U. sutsugamushi: After 5 days of culture of the winter spores of U. sutsugamushi inoculated on the WA plate, the winter spores began to form promycelia. After another 2 days of growth, a bundle of filamentous primary basidiospores would grow on the top of the promycelia. The cells of the primary basidiospores The protoplasm will enter the primary hyphae and eventually migrate into the interior of the primary basidiospore, prompting the primary hyphae to form a septum. In the same basidiospore bundle, there are usually pairs of primary basidiospores with opposite mating types, which fuse to form H bodies through a short conjugation process. The H bodies further differentiate into infective hyphae, vegetative hyphae, and sausage-shaped or filamentous secondary basidiospores. Secondary basidiospores are eventually formed on basidiospore stalks and released forcefully. The secondary basidiospores are transferred to PDA medium, and after about 17 days of culture, small white colonies will form). Due to the difference in pH of the buffer system, the time of spore germination is slightly different, and the trace amount of H2O2 in the buffer system has almost no effect on the germination of winter spores. Under the microscope, the germination of winter spores was not observed in the four material groups, but the morphology of winter spores was found to have changed.

[0053] 3. The metabolites of winter spores in all groups were transferred from WA to PDA medium for culture for two weeks. It was observed that small white colonies grew on the PDA medium of the four control groups, and no colonies were seen on the PDA plates of the four material groups. According to the experimental results, it was confirmed that the winter spores of the light stinking powder fungus failed to germinate and produce secondary basidiospores after being treated with the buffer solutions of the four materials, so they could not form colonies visible to the naked eye.

[0054] 4. After the winter spores incubated in different buffer systems were washed, centrifuged and low-temperature dried, SEM was used to conduct detailed morphological observations. In the control group, the winter spores of S. sutchuenensis maintained a spherical shape with an intact surface structure. The winter spores incubated in the (pH 3.5 buffer + Fe-SAzyme) buffer system showed significant morphological changes, manifested as surface corrosion damage and significant cracks. Many holes were observed on the surface of the winter spores incubated in the (pH 4.0 buffer + Fe-SAzyme) buffer system, showing a multi-layered structure of the winter spore wall, and the originally complete spore wall became rough. The morphology of the winter spores incubated in the (pH 3.5 buffer + H2O2 + Fe-SAzyme) buffer system has been completely deformed, the surface has been severely damaged, and the winter spores have broken. The winter spores incubated in the (pH 4.0 buffer + H2O2 + Fe-SAzyme) buffer system also showed serious morphological changes, forming large depressions, and obvious cracks on the spore surface. Figure 7 shown.

[0055] 5. EPR spectroscopy was used to quantitatively analyze the signals of ROS released by Fe-SAzyme in different buffer systems. Under the conditions of pH 3.5 and pH 4.0, ROS detection was performed continuously for 5 minutes and 10 minutes in the solution containing Fe-SAzyme with or without the addition of H2O2. At the same time, the samples without Fe-SAzyme under the four conditions were measured as blank controls. According to the detection spectrum, the generation of the three ROS was not detected in the blank control group. As long as Fe-SAzyme is present in the buffer system, the generation of the three ROS can be observed. The release signals of the three ROS continued to increase with time, indicating that in the dynamic equilibrium process of ROS release and quenching, the release rate exceeded the quenching rate. The detection and analysis diagram of the three ROS is shown in Figure 8 , Fig. 9 and Fig.10 .

[0056] Example 4 Effect of Fe-SAzyme on the Inhibition of Teliospore Germination at Different Concentrations

[0057] 1. Based on the determination of the above optimal conditions for inhibiting the germination of teliospores, the inhibitory effects of different concentrations of teliospores under these conditions were further explored. Four different teliospore concentrations were set in the experiment: 10 4 pcs / mL, 10 5 pcs / mL, 10 6 pcs / mL, 10 7 / mL to evaluate the effect of teliospore concentration on germination inhibition.

[0058] 2. Electron microscopic image analysis showed that when the winter spore concentration was 10 4 / mL, the incubated teliospores generally showed serious morphological deformation, with the surface being sunken or even flattened, the teliospore wall being corroded, and the teliospores being ruptured. 5 Under the condition of 10 / mL, almost all teliospores showed severe deformation, large depressions appeared on the surface, and the spore wall was corroded and cracked. 6 / mL, the winter spores were observed to be deformed, with depressions on the surface and corrosion of the spore wall. 7 When the concentration of iodine / mL was 0.1447 W / mL, about 80% of the winter spores had depressions on their surfaces, 50% of which were small depressions. At the same time, a certain proportion of the spore walls also showed corrosion.

[0059] Example 5 Effect of incubation temperature on inhibition of teliospore germination

[0060] 1. From the experimental results of the effect of optimized temperature on enzyme activity, it can be seen that at temperatures of 20°C and 37°C, the activities of OXD and POD-like enzymes are at a high level. The effect of Fe-SAzyme on winter spore germination under these two temperature conditions was explored.

[0061] 2. The experimental results show that under two different incubation temperature conditions, the degree of damage to the winter spores of Ustilago farnesii is similar, both manifested as large depressions, corrosion of the winter spore wall and rupture of the winter spores, with no significant difference.

[0062] Example 6 Test on the effect of iron single atom nanozyme on the germination and growth of healthy wheat seeds

[0063] 1. Select healthy wheat grains, divide them into 5 groups, 10 grains in each group, place them in 50mL centrifuge tubes, add pure water control group, pH 3.5 buffer, (pH 3.5 buffer + H2O2), (pH 3.5 buffer + Fe-SAzyme) and (pH 3.5 buffer + H2O2 + Fe-SAzyme) solutions respectively, incubate the 5 groups in a 20℃ biochemical incubator for 1 hour, then transfer them to culture dishes, wrap the wheat grains with gauze, incubate them in a 16℃ incubator for 3 days, observe and record the germination of wheat seeds. Then plant the germinated seeds in each group in a beaker filled with nutrient soil, incubate the beaker at 16℃, and observe the emergence of wheat.

[0064] 2. Observation results: Fig.10 The pH of the solution, the enzyme activity of the material, and the trace amount of H2O2 did not affect the germination and growth of wheat seeds. All five groups of wheat seeds germinated and emerged normally, and their growth conditions were consistent. Fig.11 shown.

[0065] 3. After the wheat seedlings in the five groups grew for 40 days, the wheat seedlings were pulled out, washed, drained, cut into pieces, weighed about 0.5g, and the iron content of each group of wheat seedlings was detected by ICP-MS. After testing, the iron content of the five groups of wheat seedlings was 13.33mg / kg, 13.52mg / kg, 11.50mg / kg, 13.15mg / kg, and 11.37mg / kg, respectively. There was no significant difference in the iron content of each group of wheat seedlings, indicating that during the 40 days of wheat growth, iron single-atom nanoparticles did not accumulate in the wheat seedlings.

Claims

1. Application of single-atom iron nanozymes in inhibiting smut fungus or cultivating wheat.

2. The use according to claim 1, characterized in that: The inhibition of T. tiliaceus is achieved by using the teliospores of T. tiliaceus.

3. The use according to claim 1, characterized in that: The wheat cultivation is applied in cultivating wheat for germination or seedling growth.

4. The use according to claim 1, 2 or 3, characterized in that: The preparation method of the iron single-atom nanozyme comprises the following steps: 1) Weigh Zn(NO3)2•6H2O, Fe(NO3)3•9H2O and CTAB and mix them to obtain a mixed metal salt; 2) dissolving the mixed metal salt obtained in step 1) in deionized water to obtain a mixed metal salt solution; 3) preparing a 2-methylimidazole solution having a mass percentage concentration of 6.0-7.0%; 4) adding the mixed metal salt solution prepared in step 2) to the 2-methylimidazole solution prepared in step 3), stirring vigorously for 10 min to 30 min, and then standing at room temperature for 3 h to 5 h; 5) washing the product obtained in step 4) with 40%-70% by volume ethanol aqueous solution, and vacuum drying to obtain a light yellow powder; 6) The light yellow powder obtained in step 5) is placed in an alumina ark, and slowly heated to 850-950°C at a heating rate of 3°C / min-5°C / min in a tube furnace under Ar gas protection, and kept at 850-950°C for at least 2 h. After being taken out, it is naturally cooled to room temperature, and the product is collected and ground to obtain a black powder, which is an iron single-atom nanozyme.

5. The use according to claim 4, characterized in that: In the step 2), the mass concentrations of Zn(NO3)2•6H2O, Fe(NO3)3•9H2O and CTAB are 1.9-2.1%, 0.06-0.07% and 0.09-0.1%, respectively.

6. The use according to claim 1, characterized in that: The concentration of the iron single-atom nanozyme is 0.005-0.06 mg / mL.

7. The use according to claim 1, characterized in that: The application conditions include pH 3.5-5.

5.

8. The use according to claim 1, characterized in that: The application conditions also include a temperature of 20°C-37°C.

9. The use according to claim 1, characterized in that: The application conditions also include a H2O2 concentration of 4.85-29.1 mM.

10. The use according to claim 1, characterized in that: The concentration of the teliospores of the light smut fungus is 10 4 ~10 7 Pieces / mL.

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