Application of natural product santalol as agricultural fungicide in plant diseases
Santal alcohol, as an agricultural fungicide, solves the problems of drug resistance and safety of traditional fungicides. Through its highly effective inhibition of a variety of plant pathogens, it achieves green and safe disease control and has important application prospects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU UNIV
- Filing Date
- 2026-04-22
- Publication Date
- 2026-07-10
AI Technical Summary
Existing fungicides have problems with drug resistance when controlling plant diseases, and the use of traditional fungicides threatens the safety and sustainability of agricultural production. There is a need to develop agricultural fungicides with novel structures, unique mechanisms of action, high efficiency and low toxicity.
Santal alcohol is used as an agricultural fungicide to treat bacterial, fungal, and viral diseases of plants, including rice bacterial blight, citrus canker, and kiwifruit canker. Santal alcohol exhibits excellent biological activity against a variety of plant pathogens.
Santal alcohol exhibits excellent biological activity against a variety of plant pathogens, with inhibition rates and half-maximal inhibitory concentrations superior to traditional agents. It is green, safe, and can be degraded by soil microorganisms, making it suitable for the prevention and control of various plant diseases.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of plant disease control, and in particular to the application of the natural product santalol as an agricultural fungicide in the treatment of bacterial plant diseases. Background Technology
[0002] In agricultural production, plant diseases have long been a major bottleneck restricting the improvement of crop yield and quality, directly affecting the stability and sustainable development of agricultural production and posing a continuous threat to global food security. Among them, diseases caused by plant pathogenic bacteria are particularly prominent, characterized by rapid spread, wide infection range, and difficulty in control. Crops infected by pathogenic bacteria suffer from stunted growth and weakened development, resulting in a significant decrease in yield and marketable quality. In severe cases, it can cause large-scale plant death and crop failure, leading to huge economic losses in agricultural production. In food crops, bacterial leaf blight and bacterial leaf streak of rice occur on a large scale in major rice-producing areas year-round, causing significant yield losses and seriously threatening rice production safety. In fruit and vegetable cash crops, common bacterial diseases such as citrus canker, kiwifruit canker, solanaceous bacterial wilt, cruciferous soft rot, and cucumber bacterial angular leaf spot not only cause leaf and fruit drop but also severely reduce the appearance quality and commercial value of fruits, significantly reducing planting income. Plant pathogenic fungi are among the most widespread and damaging plant pathogenic microorganisms. They are diverse in species and have a wide host range, infecting almost all cultivated crops and wild plants, causing significant negative impacts on the stable development of agricultural production and ecological balance. After infecting plants, plant pathogenic fungi colonize and multiply within plant tissues, damaging plant cell structure and interfering with normal physiological metabolic processes by secreting enzymes and toxins. This leads to decreased yield, deterioration in quality, and reduced commercial value of agricultural products; in severe cases, it can cause the entire plant to wither and die. Plant viral diseases, due to their unique modes of infection, can also cause irreversible damage to plants.
[0003] Given the serious harm plant diseases cause to agricultural production, and their characteristics of being explosive, epidemic, devastating, and difficult to control, chemical control is a necessary measure. In the context of the national green development of agriculture, with the rapid development of agriculture and the increasing prominence of pest and disease problems, plant disease control should adapt to the times, balancing the dual goals of disease control and reduction of chemical pesticide use. Vigorously promoting green control technologies guided by the principle of "prevention first, integrated management" is imperative. Agricultural fungicides, due to their high efficiency and rapid effect, have become the most important means of controlling plant diseases and a major measure to ensure high and stable crop yields in my country. Agricultural fungicides can effectively control plant diseases, ensure healthy crop growth, and thus improve crop yield and quality, playing a crucial role in agricultural production. However, although traditional fungicides can inhibit diseases to a certain extent, their frequent use and single antimicrobial action mode have led to increasingly serious problems of plant pathogen resistance. Therefore, there is an urgent need to develop antibacterial drugs with novel structures, unique mechanisms of action, and high efficiency and low toxicity to replace traditional fungicides in order to improve the safety and sustainability of agricultural production. Summary of the Invention
[0004] The purpose of this invention is to provide the application of santalol as an agricultural fungicide in plant diseases, so as to solve the problems existing in the prior art.
[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides the application of santalol as an agricultural fungicide in plant diseases, wherein the structural formula of santalol is as follows: .
[0006] The application of the natural product santalol as an agricultural fungicide in plant diseases, wherein the plant diseases include bacterial plant diseases, fungal plant diseases, and viral plant diseases, and wherein the application of the natural product santalol as an agricultural fungicide in plant diseases is characterized in that: the plant diseases include those caused by *Rhizoctonia solani*, *Citrus canker*, *Actinidia kiwifruit*, *Xanthomonas rice* (a pathogenic strain of *Rhizoctonia solani*), *Xanthomonas carpetii*, *Xanthomonas brasiliensis* (a pathogenic strain of *Rhizoctonia solani*), *Pseudomonas syringae* (a pathogenic strain of *Rhizoctonia solani*), *Actinidia kiwifruit*, *Rhizoctonia solani*, *Rhizoctonia solani* (a pathogenic strain of *Rhizoctonia solani*), ...
[0007] The plant diseases mentioned are preferably caused by rice bacterial blight fungus, citrus canker fungus, kiwifruit canker fungus, grape colocynosis fungus, rice rhizobium, sorghum spore spore fungus, and tobacco mosaic virus.
[0008] Preferably, the application of santalol in the control of rice bacterial blight pathogens, with its half-maximal inhibitory concentration (EC50) against the pathogen is described. 50 The concentration was 41.16 mg / L.
[0009] Preferably, the application of santalol in the control of citrus canker pathogens, with its half-maximal inhibitory concentration (EC50) against citrus canker pathogens is described. 50 The concentration was 15.93 mg / L.
[0010] Preferably, the application of santalol in the control of kiwifruit canker pathogens, with its half-maximal inhibitory concentration (EC50) against the kiwifruit canker pathogen being... 50 The concentration was 30.40 mg / L.
[0011] This invention is the first to study the use of santalol as a fungicide to control plant diseases. Compared with traditional fungicides, santalol, as a natural product, has advantages such as being green, safe, and degradable by soil microorganisms. This invention experimentally verified the half-maximal inhibitory concentration (EC50) of santalol against rice bacterial blight pathogens. 50 The concentration was 41.16 mg / L, and the half-maximal inhibitory concentration (EC50) against citrus canker pathogens was 41.16 mg / L. 50 The concentration was 15.93 mg / L, and the half-maximal inhibitory concentration (EC50) against *Actinidia kiwifruit* causal agent was [missing value]. 50 The concentration was 30.40 mg / L, which was superior to the commercial control drug, tebuconazole, and superior to the commercial drug, thiamethoxam (EC). 50 =70.13 mg / L) and thiamethoxam (EC) 50 >100 mg / L). Santalum alcohol exhibited inhibition rates of 31.25%, 16.13%, and 25.39% against *Botrytis cinerea*, *Rhizoctonia solani*, and *Colletotrichum sacchari*, respectively, with its inhibitory activity against *Rhizoctonia solani* being superior to the control agent, malathionine. Santalum alcohol also demonstrated certain therapeutic, protective, and inactivating activities against plant pathogenic viruses (TMV). At a concentration of 500 mg / L, the therapeutic, protective, and inactivating activities of Santalum alcohol were 41.09%, 37.86%, and 48.95%, respectively, with its therapeutic activity slightly lower than that of the control agent, ningnanmycin. A series of bioactivity tests showed that the Santalum alcohol protected by this invention possesses excellent bioactivity against plant pathogenic bacteria, and also exhibits certain bioactivity against plant pathogenic viruses and fungi, demonstrating significant market value and application prospects. Detailed Implementation
[0012] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0013] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0014] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0015] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.
[0016] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0017] In this invention, santalol (95%) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. The rice bacterial blight pathogen was provided by Professor Zhou Mingguo's research group at Nanjing Agricultural University; the citrus canker pathogen was preserved by Professor Yang Song's research group; and the kiwifruit canker pathogen was provided by Professor Zou Lifang's research group at Shanghai Jiao Tong University.
[0018] Example 1: Bioactivity test of santalol against plant pathogenic bacteria The experimental subject was rice bacterial blight pathogen ( Xoo ), Citrus canker pathogen ( Right Kiwi fruit canker pathogen ( Ps Thiazole zinc (30% wettable suspension) and thiabendazole copper (20% wettable suspension) were used as experimental controls, and DMSO dissolved in the culture medium was used as a blank control.
[0019] (1) Inoculate rice bacterial blight fungus, citrus canker fungus and kiwi fruit canker fungus into NB medium and culture them in a constant temperature shaker at 28 ℃ and 220 rpm until the logarithmic growth phase for later use.
[0020] (2) Prepare NB liquid culture media containing different concentrations of the selected santalin, thiamethoxam zinc (30% wettable suspension), and thiamethoxam copper (20% wettable suspension) at concentrations of 200, 100, 50, 25, 12.5, and 6.25 μg / mL, respectively, and add 5 mL of each medium to a test tube.
[0021] (3) Add 40 µL of NB liquid culture medium containing plant pathogens to the test tubes containing different concentrations of reagents in step 1.2, and shake them in a constant temperature shaker at 28 ℃ and 220 rpm. The rice bacterial blight pathogen is cultured for 36 h, the citrus canker pathogen for 48 h, and the kiwi fruit canker pathogen for 28 h.
[0022] (4) Measure the OD of bacterial solutions of various concentrations on a spectrophotometer. 595 The value was also measured, and the OD of the corresponding concentration of sterile NB liquid culture medium containing the toxin was also determined. 595 value.
[0023] Corrected OD value = OD value of sterile culture medium - OD value of sterile culture medium Inhibition rate = [(OD value of bacterial suspension in calibration control medium - OD value of toxic culture medium in calibration) / OD value of bacterial suspension in calibration control medium] × 100% The experimental results are shown in Table 1.
[0024] Table 1. EC50 of santalol against plant pathogenic bacteria *Bacillus oryzae* (rice bacterial blight), *Citrus canker* (citrus canker), and *Actinidia kiwifruit canker*. 50 value
[0025] EC 50 Median effective concentration (MEC) is an important indicator for evaluating the sensitivity of plant pathogens to compounds, and it is also a crucial parameter for setting the compound concentration when studying the mechanism of action of target compounds. In concentration gradient experiments, six appropriate concentrations were set using the two-fold dilution method. Finally, the inhibition rate of the agent against the plant pathogen and the agent concentration were converted into logarithmic values, and the toxicity curve was obtained through regression analysis using SPSS software to calculate the EC50. 50 .
[0026] As shown in Table 1, santalol exhibits good in vitro antibacterial activity against *Bacillus thuringiensis*, and its EC50 content is [missing information]. 50 =41.16 mg / L, its in vitro antibacterial activity was significantly better than that of the commercial control drug thiabendazole (EC).50 =70.04 mg / L); Santal alcohol exhibits excellent in vitro antibacterial activity against *Citrus canker*, with an EC50 concentration of 70.04 mg / L. 50 =15.93 mg / L, its in vitro antibacterial activity is significantly superior to that of the commercial drug thiazolium zinc (EC). 50 =32.54 mg / L) and thiamethoxam (EC) 50 =87.89 mg / L); Santalum alcohol exhibits excellent in vitro antibacterial activity against *Actinidia kiwifruit* causal agent, with its EC50 concentration being 87.89 mg / L. 50 =30.40 mg / L, its in vitro antibacterial activity was significantly better than that of the commercial control drug tebuconazole, which was superior to that of the commercial drug thiamethoxam (EC). 50 =70.13 mg / L) and thiamethoxam (EC) 50 >100mg / L).
[0027] Example 2: Bioactivity test of the natural product santalol against plant pathogenic fungi. The mycelial growth rate method, also known as the toxic medium method, is one of the routine methods for determining the toxicity of fungicides. The main principle is to mix the test agent with a culture medium and measure the toxicity of the agent by the rate at which colonies grow on the toxic medium. In this example, *Staphylococcus aureus*, *Rhizoctonia solani*, and *Anthracnose fungi* of the tea plant were used as test subjects, with DMSO as a blank control. The specific procedures are as follows: 1) Weigh an appropriate amount of drug according to the test concentration, dissolve it with DMSO (the amount should not exceed 1% of the final toxic medium), then add 0.1% Tween 20 solution to make up to 10 mL, pour it into 90 mL of melted PDA medium, mix well, and then pour it into 9 petri dishes for later use; 2) Sterilize the punch (with an inner diameter of 5 mm) by flame, and after it cools, punch holes in the hyphae near the edge of the pre-activated strain, and use an inoculation needle to place the hyphae facet to the center of the toxic medium. After treatment, place them uniformly at 25℃ for incubation; 3) After the colony diameter of the control group grows to 5.5-6.6 cm, use the cross-cross method to determine the colony diameter of the control group and each drug treatment group; 4) Calculate the inhibition rate (%) using the following formula: Inhibition rate % = (CT) / (C-0.5)×100. Where, C is the colony diameter of the control group, T is the colony diameter of the drug treatment group, and 0.5 cm is the diameter of the inoculated mycelium.
[0028] Table 2 Inhibitory activity of santalol against plant pathogenic fungi (25 μg / mL)
[0029] Table 2 shows that santalol exhibits certain in vitro antibacterial activity against plant pathogenic fungi (such as *Botrytis cinerea*, *Rhizoctonia solani*, and *Colletotrichum sacchariformis*). At a concentration of 25 μg / mL, santalol showed inhibition rates of 31.25%, 16.13%, and 25.39% against *Botrytis cinerea*, *Rhizoctonia solani*, and *Colletotrichum sacchariformis*, respectively. Its inhibitory activity against *Rhizoctonia solani* was superior to that of the control agent, malathionine.
[0030] Example 3: Bioactivity test of santalol against plant pathogen viruses The half-leaf spot method was used to determine the in vivo activity of the compound against tobacco mosaic virus (TMV). 3 mg of the test compound was accurately weighed into a weighing bottle, and 60 μL of DMSO solvent was added to dissolve it completely. A 500 mg / L compound solution was prepared by dissolving the compound in double-distilled water containing 1 wt% Tween 20. Separately, 250 μL of 2 wt% ribavirin aqueous solution was dissolved in 60 μL of DMSO solvent and an appropriate amount of double-distilled water containing 1 wt% Tween 20 to prepare a 500 mg / L ribavirin solution.
[0031] The in vivo therapeutic activity of the agent against TMV infection. Uniformly growing heart-leaf tobacco plants were selected, and virus solution (concentration 6 × 10⁻⁶) was first collected using a parallel dipper. -3 (mg / mL) The virus solution was manually inoculated onto the leaf surface (whole leaf) along the veins, using a friction rubbing motion. The inoculation intensity on both leaves should be kept as consistent as possible. The leaves were supported under a flat wooden board. After the virus solution dried, the emery was rinsed off the leaves with running water. After the leaves dried, the left half of the leaf was treated with the solution, and the right half was treated with sterilized water as a control. Three plants were treated per dose, each with 3-4 leaves. The plants were then placed in a light incubator with humidity control at 23 ℃ and 10000 LuX of light. The number of necrotic spots was observed and recorded after 2-4 days. Each treatment was repeated three times, and the inhibition rate (Y) was calculated using the following formula: Y (%) = (RL) / R × 100% Where: Y is the inhibition rate of the compound against tobacco mosaic virus; R is the number of necrotic spots in the control group (right half of the leaf); L is the number of necrotic spots in the treatment group (left half of the leaf).
[0032] The embodiments of the present invention are provided to illustrate the technical solutions of the present invention, but the content of the embodiments is not limited thereto. The experimental results are shown in Table 3.
[0033] Table 3. Activity test of santalol against plant pathogen virus TMV (500 mg / L)
[0034] As shown in Table 3, santalol exhibited certain therapeutic, protective, and inactivating activities against the plant pathogenic virus TMV in in vivo experiments. At a concentration of 500 mg / L, the therapeutic, protective, and inactivating activities of santalol were 41.09%, 37.86%, and 48.95%, respectively.
[0035] In summary, through a series of bioactivity tests, the results show that the santalol protected by this invention has excellent bioactivity against plant pathogenic bacteria, and also has certain bioactivity against plant pathogenic viruses and fungi, which has important research value and application prospects.
[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A novel use of the natural product santalol, characterized in that, Application of fungicides in plant diseases.
2. The application of the natural product santalol as an agricultural fungicide in plant diseases according to claim 1, characterized in that: The plant diseases mentioned include those caused by *Rhizoctonia solani*, *Citrus canker*, *Actinidia kiwifruit*, *Xanthomonas rice* (a pathogenic strain of *Rhizoctonia solani*), *Xanthomonas carpetii*, *Xanthomonas brasiliensis* (a pathogenic strain of *Rhizoctonia solani*), *Pseudomonas syringae* (a pathogenic strain of *Rhizoctonia solani*), *Actinidia kiwifruit* (a pathogenic strain of *Rhizoctonia solani*), *Rhizoctonia solani* (a pathogenic strain of *Rhizoctonia solani*), *Pseudomonas syringae* (a pathogenic strain of *Rhizoctonia solani*), and *Rhizoctonia solani* (a pathogenic strain of *Rhizoctonia solani*). The plant fungal diseases mentioned are those caused by *Rhizoctonia solani*, *Fusarium wilt*, *Botrytis cinerea*, or *Colletotrichum sorghum*. The plant viral diseases mentioned are those caused by tobacco mosaic virus.
3. The application of santalol, a natural product according to claim 2, as an agricultural fungicide in plant diseases, characterized in that: The plant diseases mentioned are those caused by rice bacterial blight fungus, citrus canker fungus, kiwifruit canker fungus, grape colocynosis fungus, rice rhizobium, sorghum spore spore fungus, and tobacco mosaic virus.
4. The application according to claim 3, characterized in that: Application of santalol in the control of rice bacterial blight pathogen, and its half-maximal inhibitory concentration (EC50) against the pathogen. 50 The concentration was 41.16 mg / L.
5. The application according to claim 3, characterized in that, Application of santalol in the control of citrus canker pathogen, and its half-maximal inhibitory concentration (EC50) against citrus canker pathogen. 50 It was 15.93 mg / L.
6. The application according to claim 3, characterized in that, Application of santalol in the control of kiwifruit canker pathogen, and its half-maximal inhibitory concentration (EC50) against kiwifruit canker pathogen. 50 The concentration was 30.40 mg / L.