Application of Triphenylbismuth Dichloride in Controlling Phytopathogenic Fungi

Abstract

The present invention provides the application of triphenylbismuth dichloride in preventing and controlling phytopathogenic fungi, belonging to the technical field of bacteriostatic agents. The present invention provides the application of triphenylbismuth dichloride in preventing and controlling phytopathogenic fungi, and specifically studies the effects of triphenylbismuth dichloride on the growth and pathogenicity of Sclerotinia sclerotiorum. The triphenylbismuth dichloride of the present invention can cause abnormal colony morphology of Sclerotinia sclerotiorum and has a certain inhibitory effect on various pathogenic fungi including Sclerotinia sclerotiorum. The triphenylbismuth dichloride of the present invention has a good control effect on crop sclerotinia blight caused by Sclerotinia sclerotiorum. The triphenylbismuth dichloride of the present invention is safe for plants, and spraying 200 ppm of triphenylbismuth dichloride on Arabidopsis thaliana has no obvious effect on the growth and seed yield of Arabidopsis thaliana.

Description

Technical Field

[0001] The present invention belongs to the technical field of bacteriostatic agents, and particularly relates to the application of triphenylbismuth dichloride in preventing and controlling plant pathogenic fungi. Background Art

[0002] Bismuth compounds were proven to have antibacterial activity as early as the 1960s and have been widely used in biomedicine. For example, bismuth compounds have been used to treat various gastrointestinal diseases due to their astringent and antidiarrheal properties, and have been topically applied to skin diseases and anorectal diseases such as hemorrhoids; insoluble trivalent bismuth compounds such as bismuth subcarbonate are active against Helicobacter pylori and can be used to treat peptic ulcers; bismuth-based metal complexes related to bismuth potassium citrate can effectively inhibit the activity of metallo-β-lactamase (MBL) in superbugs and curb the further enhancement of their drug resistance, greatly improving the efficacy and service life of existing antibiotics. Triphenylbismuth dichloride (TPBC) has strong antibacterial activity against many pathogenic bacteria, including drug-resistant strains such as methicillin-resistant Staphylococcus aureus and Enterococcus faecalis. Birkenstock et al. showed through metabolomics and enzymology analysis that triphenylbismuth dichloride may block the bacterial pyruvate dehydrogenase complex (PDC), thereby disrupting central metabolic activity. However, the effect of triphenylbismuth dichloride on fungi has not been reported.

[0003] References:

[0004] Birkenstock T, Liebeke M, Winstel V, Krismer B, Gekeler C, Niemiec MJ, Bisswanger H, Lalk M, Peschel A. Exometabolome analysis identifies pyruvate dehydrogenase as a target for the antibiotic triphenylbismuth dichloride in multiresistant bacterial pathogens. J Biol Chem. 2012, 287(4):2887 - 2895. Summary of the Invention

[0005] The purpose of the present invention is to provide the application of pyruvate dehydrogenase inhibitors in preventing and controlling plant pathogenic fungi, and the pyruvate dehydrogenase inhibitors have bacteriostatic effects on a variety of plant pathogenic fungi.

[0006] The present invention provides the application of pyruvate dehydrogenase inhibitors in preventing and controlling plant pathogenic fungi.

[0007] Preferably, the pyruvate dehydrogenase inhibitor includes triphenylbismuth dichloride.

[0008] Preferably, the plant pathogenic fungi include at least one of the following fungi: Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium graminearum, and Rhizoctonia solani.

[0009] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in preventing and controlling plant diseases caused by Sclerotinia sclerotiorum.

[0010] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Botrytis cinerea.

[0011] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Fusarium graminearum.

[0012] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Rhizoctonia solani.

[0013] The present invention also provides a plant pathogenic fungi bacteriostatic agent, the active ingredient of the plant pathogenic fungi bacteriostatic agent includes triphenylbismuth dichloride, and also includes excipients.

[0014] Preferably, in the plant pathogenic fungi bacteriostatic agent, the concentration of triphenylbismuth dichloride is not less than 5 ppm.

[0015] Beneficial effects: The present invention provides the application of pyruvate dehydrogenase inhibitor in preventing and controlling plant pathogenic fungi, specifically studied the effect of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum, and the EC 50 is 23.35 ppm. It is also confirmed in the examples of the present invention that triphenylbismuth dichloride may be toxic to Sclerotinia sclerotiorum, making the mycelial growth slow and the colony morphology abnormal, and even making some Sclerotinia sclerotiorum not develop diseases; triphenylbismuth dichloride has a certain inhibitory effect on the growth of Sclerotinia sclerotiorum Sunf-M, Botrytis cinerea B05.10, Fusarium graminearum PH-1, and Rhizoctonia solani WH-1. The inhibitory effect of triphenylbismuth dichloride on Sunf-M is the strongest. When the treatment concentration is 80 ppm, the inhibition rate of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum is 80.09%, while the inhibition rate on Rhizoctonia solani is only 44.59%. The present invention also confirms the safety of triphenylbismuth dichloride to plants. Spraying 200 ppm triphenylbismuth dichloride on Arabidopsis thaliana has no obvious effect on the growth and seed yield of Arabidopsis thaliana. Description of the Drawings

[0016] Figure 1 It is a result diagram of the effect of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum;

[0017] Figure 2 Figure showing the effect of triphenylbismuth dichloride on the pathogenicity of Sclerotinia sclerotiorum;

[0018] Figure 3 Figure showing the effect of triphenylbismuth dichloride treatment on the growth and yield of Arabidopsis thaliana. Detailed implementation methods

[0019] The present invention provides the application of pyruvate dehydrogenase inhibitors in controlling plant pathogenic fungi.

[0020] The pyruvate dehydrogenase inhibitor described in the present invention preferably includes bismuth compounds. In the examples, triphenylbismuth dichloride is taken as an example for illustration, but it cannot be considered as the entire scope of protection of the present invention. The plant pathogenic fungi described in the present invention preferably include at least one of the following fungi: Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium graminearum, and Rhizoctonia solani.

[0021] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in preventing and controlling plant diseases caused by Sclerotinia sclerotiorum.

[0022] In the examples of the present invention, it is confirmed that triphenylbismuth dichloride can affect the growth of Sclerotinia sclerotiorum and may be toxic. When the concentration is sufficient, it can make Sclerotinia sclerotiorum lose its pathogenic ability. When the treatment concentration is 80 ppm, the inhibition rate of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum for 48 h is 80.09%.

[0023] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Botrytis cinerea. After adding triphenylbismuth dichloride to the PDA medium, the inhibition rate on Botrytis cinerea is significantly higher than that of the common fungicide carbendazim. When the treatment concentration is 80 ppm, the inhibition rate of triphenylbismuth dichloride on Botrytis cinerea is 66.46%, while the inhibition rate of carbendazim on Botrytis cinerea is only 6.22%. It may be due to the fact that Botrytis cinerea already has a certain resistance to carbendazim.

[0024] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Fusarium graminearum. When the treatment concentration is 80 ppm, the inhibition rate of triphenylbismuth dichloride on Fusarium graminearum is 56.80%.

[0025] The present invention also provides the application of triphenylbismuth dichloride as an active ingredient of a bacteriostatic agent in inhibiting the growth of Rhizoctonia solani. In the examples of the present invention, when the treatment concentration of triphenylbismuth dichloride is 80 ppm, the inhibition rate of triphenylbismuth dichloride on Rhizoctonia solani is 44.59%.

[0026] The present invention also provides a plant pathogenic fungi bacteriostatic agent, the active ingredient of which includes triphenylbismuth dichloride and also includes excipients.

[0027] In the present invention, in the plant pathogenic fungi bacteriostatic agent, the concentration of triphenylbismuth dichloride is not less than 5 ppm. And the EC 50 of triphenylbismuth dichloride against Sclerotinia sclerotiorum is 23.35 ppm.

[0028] To further illustrate the present invention, the following examples are used to describe in detail the application of triphenylbismuth dichloride provided by the present invention in preventing and controlling plant pathogenic fungi, but they should not be construed as limiting the protection scope of the present invention.

[0029] Example 1

[0030] Effect of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum

[0031] Triphenylbismuth dichloride with different final concentrations (5 ppm, 10 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm) was added to the PDA medium, and the medium without adding any substance and the medium added with DMSO were used as controls. Fresh mycelial blocks of Sclerotinia sclerotiorum were inoculated and cultured at 20 °C.

[0032] The results are as Figure 1 shown that the growth of Sclerotinia sclerotiorum was significantly inhibited at a final concentration of 5 ppm of triphenylbismuth dichloride, and the colony morphology was abnormal. After culturing in the PDA medium containing 80 ppm of triphenylbismuth dichloride for 24 h, Sclerotinia sclerotiorum hardly grew, and the inhibition rate of its growth reached 97.89%.

[0033] Inhibition rate (%) = (average value of fungal hyphal diameter in the control group - average value of fungal hyphal diameter in the treatment group) / (average value of fungal hyphal diameter in the control group - diameter of the inoculated mycelial block) × 100%, the same below.

[0034] The average inhibition rate of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum for 24 h is shown in Table 1.

[0035] Table 1 Average inhibition rate of triphenylbismuth dichloride on the growth of Sclerotinia sclerotiorum for 24 h

[0036]

[0037] Calculate the inhibition rate after culturing for 24 h at different agent concentrations, convert the agent concentration into concentration logarithm (X), and convert the inhibition rate into probit value (Y). According to the linear relationship between X and Y ( Figure 1 ) to obtain the EC 50 of triphenylbismuth dichloride is 23.35 ppm.

[0038] Example 2

[0039] Effect of pyruvate dehydrogenase inhibitor triphenylbismuth dichloride on the pathogenicity of Sclerotinia sclerotiorum

[0040] Prepare 20 mL of triphenylbismuth dichloride solutions with different concentrations (50 ppm, 100 ppm, 200 ppm, 250 ppm) respectively, and spray them on the detached rape leaves. Use ddH 2 O treatment and DMSO treatment as controls. After leaving them for 3 - 4 h until the leaves are dry, inoculate fresh Sclerotinia sclerotiorum mycelial blocks. Observe 48 h after inoculation. Compared with the ddH 2 O treatment, the lesion area is significantly reduced in the 100 ppm triphenylbismuth dichloride treatment. Compared with the ddH 2 O treatment, the lesion area caused by Sclerotinia sclerotiorum is extremely significantly reduced in the 200 ppm triphenylbismuth dichloride treatment and some leaves do not develop diseases after inoculation ( Figure 2 ).

[0041] Observe 5 d after inoculation. Some leaves treated with 200 ppm triphenylbismuth dichloride solution and 250 ppm triphenylbismuth dichloride solution still do not develop diseases. Pick the non - diseased mycelial blocks and transfer them to PDA medium for culturing. Observe after 48 h. The growth of the mycelia is slow and the colony morphology is abnormal. It may be that triphenylbismuth dichloride has an inhibitory effect on the growth of Sclerotinia sclerotiorum.

[0042] Directly spray 50 mL of triphenylbismuth dichloride solution with a final concentration of 200 ppm on the living rape plants, use DMSO treatment as a control. Take pictures, observe and measure the lesion diameter 48 h after inoculation. Similar to the results of inoculation on detached leaves, after treatment with 200 ppm triphenylbismuth dichloride solution, the lesion area caused by Sclerotinia sclerotiorum is significantly reduced and some Sclerotinia sclerotiorum do not develop diseases ( Figure 2 ).

[0043] Example 3

[0044] Effect of triphenylbismuth dichloride on the growth rate of different strains

[0045] Use a 5 - mm puncher to take fresh Sclerotinia sclerotiorum mycelial blocks, and inoculate the mycelial blocks on the surface of PDA medium supplemented with 5 ppm, 10 ppm, 30 ppm, 50 ppm, 80 ppm triphenylbismuth dichloride and carbendazim respectively. Use PDA added with DMSO, 0.1 M HCl (add 20 μL of the corresponding reagent to every 50 mL of PDA) and PDA without adding any substance as controls. Culture at 20 °C until the control (PDA) fills a 9 - cm petri dish, calculate the inhibition rate and take pictures for recording.

[0046] The results are shown in Table 2. Both bismuth triphenyl dichloride and carbendazim have certain inhibitory effects on the growth of the ascomycete Sclerotinia sclerotiorum Sunf-M, Botrytis cinerea B05.10, Fusarium graminearum PH-1, and the basidiomycete Rhizoctonia solani WH-1. Bismuth triphenyl dichloride has the strongest inhibitory effect on Sunf-M. When the treatment concentration is 80 ppm, the inhibition rate of bismuth triphenyl dichloride on the growth of Sclerotinia sclerotiorum for 48 h is 80.09%, and the inhibition rates on the growth of Botrytis cinerea and Fusarium graminearum also reach over 50%, while the inhibition rate on Rhizoctonia solani is only 44.59%. This indicates that bismuth triphenyl dichloride may have selectivity in its effects on different fungi, and its control effect on diseases caused by ascomycetes may be better than that on basidiomycetes.

[0047] Table 2 Bacteriostatic efficiency of bismuth triphenyl dichloride at different concentrations

[0048]

[0049] To further compare the efficacy differences between bismuth triphenyl dichloride and the commonly used fungicide carbendazim, the inhibition rates were calculated after treatment with different concentrations of carbendazim. The results are shown in the following table. When using 10 ppm of carbendazim, the bacteriostatic effects on Sclerotinia sclerotiorum Sunf-M, Fusarium graminearum PH-1, and Rhizoctonia solani WH-1 are all over 80%. When using 50 ppm of carbendazim for treatment, the inhibition rate on Botrytis cinerea is the highest, but it is only 32.06%, which is significantly lower than the inhibition rate of bismuth triphenyl dichloride on Botrytis cinerea at this concentration. This indicates that Botrytis cinerea may already have a certain degree of resistance to the commonly used fungicide carbendazim, and the newly screened chemical agent has high application potential in agricultural production.

[0050] Table 3 Bacteriostatic efficiency of carbendazim at different concentrations

[0051]

[0052] Example 4

[0053] Effect of bismuth triphenyl dichloride treatment on the growth and yield of Arabidopsis thaliana

[0054] To explore whether the treatment with bismuth triphenyl dichloride has an impact on plant growth, Arabidopsis thaliana plants grown for 5 weeks were sprayed with a 200 ppm solution of bismuth triphenyl dichloride. ddH 2 O and DMSO treatments were used as controls. Each pot with 4 Arabidopsis thaliana plants was used as a replicate, and there were 3 replicates for each treatment. 20 mL of the corresponding solution was sprayed for each treatment. After treatment, the plants were cultured under normal light, the seeds were collected and weighed. As Figure 3 shown, spraying 200 ppm of bismuth triphenyl dichloride on Arabidopsis thaliana has no obvious effect on the growth and seed yield of Arabidopsis thaliana.

[0055] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all of them. Other embodiments can be obtained based on these embodiments without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. Application of triphenylbismuth dichloride in preventing and controlling phytopathogenic fungi, characterized in that, the phytopathogenic fungi are Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium graminearum or Rhizoctonia solani; the concentration of triphenylbismuth dichloride is not less than 5 ppm.

2. Application of triphenylbismuth dichloride as an active ingredient of an antibacterial agent in preventing and controlling plant diseases caused by Sclerotinia sclerotiorum, characterized in that, the concentration of triphenylbismuth dichloride in the antibacterial agent is not less than 5 ppm.

3. Application of triphenylbismuth dichloride as an active ingredient of an antibacterial agent in inhibiting the growth of Botrytis cinerea, characterized in that, the concentration of triphenylbismuth dichloride in the antibacterial agent is not less than 5 ppm.

4. Application of triphenylbismuth dichloride as an active ingredient of an antibacterial agent in inhibiting the growth of Fusarium graminearum, characterized in that, the concentration of triphenylbismuth dichloride in the antibacterial agent is not less than 5 ppm.

5. Application of triphenylbismuth dichloride as an active ingredient of an antibacterial agent in inhibiting the growth of Rhizoctonia solani, characterized in that, the concentration of triphenylbismuth dichloride in the antibacterial agent is not less than 5 ppm.

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