New application of quinolone compounds in preventing and controlling plant bacterial disease citrus canker

Abstract

The invention discloses a novel use of quinolone compounds as fungicides in the prevention and treatment of citrus canker, a bacterial disease of crops. The quinolone compounds are fleroxacin, enoxacin, gatifloxacin, moxifloxacin hydrochloride, enrofloxacin, marbofloxacin, norfloxacin, monofloxacin mesylate, prulifloxacin, banofloxacin, pazufloxacin mesylate, pipemidic acid, sparfloxacin, difloxacin hydrochloride, lomefloxacin hydrochloride, pefloxacin, mesylate Tosufloxacin, cinoxacin, garefoxacin, besifloxacin hydrochloride, ofloxacin, nalidixic acid, clinafloxacin and sitafloxacin can prevent and control bacterial diseases caused by citrus canker bacteria. In particular, gatifloxacin, moxifloxacin hydrochloride, monofloxacin mesylate, sparfloxacin, tosufloxacin mesylate, clinafloxacin and sitafloxacin show excellent antibacterial activity against citrus canker bacteria, and can realize their new use in the prevention and control of bacterial diseases of crops.

Description

Technical Field

[0001] The present invention relates to the field of agricultural fungicides, and more specifically, to a new use of quinolone compounds as fungicides in preventing and treating plant bacterial diseases such as citrus canker. Background Art

[0002] In recent years, bacterial diseases have become the second most common disease in my country's agricultural production, second only to fungal diseases. Plant bacterial diseases and the complications they induce seriously threaten the healthy development of agriculture and food security, and have become one of the biggest problems that should be solved immediately in agriculture. However, the types and quantities of pesticides for the prevention and control of bacterial diseases in my country are currently limited, and there are few new varieties. Long-term use of these agents has led to increasingly serious drug resistance in pathogens and a decreasing effect of existing pesticides. Therefore, research and development of new pesticides that are efficient, low-toxic, and low-residue and can effectively control bacterial diseases has become one of the important goals of current pesticide development.

[0003] Quinolone compounds are synthetic antibacterial drugs. Their mechanism of action is to selectively inhibit bacterial DNA gyrase and topoisomerase IV, prevent bacterial DNA synthesis and replication, and show strong bactericidal activity against most Gram-positive and Gram-negative bacteria. Quinolone compounds have the characteristics of broad antibacterial spectrum, strong activity, high bioavailability, no cross-resistance with other antibacterial drugs, and low toxic and side effects, and are widely used in the fields of medicine and veterinary medicine. The prior art discloses that oxolinic acid (CN 201910307325), ciprofloxacin (CN 201510069315), levofloxacin (CN201810599892) and nadifloxacin (CN201811479010) show good control effects on bacterial diseases such as crops and flowers, but there is no report on the use of other quinolone compounds as fungicides in the prevention and control of plant bacterial diseases such as citrus canker.

[0004] Based on this, the present invention uses 24 quinolone compounds as research objects, evaluates their antibacterial activity against plant pathogenic bacteria, and finds that most quinolone compounds show strong antibacterial activity against the plant bacterial disease citrus canker, especially gatifloxacin, moxifloxacin hydrochloride, monofloxacin mesylate, sparfloxacin, tosufloxacin mesylate, clinafloxacin, sitafloxacin show excellent inhibitory effect against citrus canker bacteria. Therefore, quinolone compounds have good development prospects as agents for preventing and treating important bacterial diseases of crops, especially citrus canker. Summary of the invention

[0005] The purpose of the present invention is to use quinolone compounds for the prevention and treatment of bacterial diseases of crops, so as to expand the application scope of various agents and to screen and obtain some highly effective and low-toxic pesticide fungicides.

[0006] The invention discloses a novel use of quinolone compounds as fungicides in preventing and controlling bacterial diseases of crops. The quinolone compounds are fleroxacin, enoxacin, gatifloxacin, moxifloxacin hydrochloride, enrofloxacin, marbofloxacin, norfloxacin, monofloxacin mesylate, prulifloxacin, banofloxacin, pazufloxacin mesylate, pipemidic acid, sparfloxacin, difloxacin hydrochloride, lomefloxacin hydrochloride, pefloxacin, tosufloxacin mesylate, cinoxacin, garefoxacin, besifloxacin hydrochloride, ofloxacin, nalidixic acid, clinafloxacin and sitafloxacin, which can prevent and control bacterial diseases of crops caused by citrus canker bacteria.

[0007] Compared with the prior art, the present invention has the following effects: most quinolone compounds show excellent antibacterial activity against Xanthomonas citri var. citri, and can be used in the application of Xanthomonas citri var. citri infestans, a bacterial disease of agricultural crops. DETAILED DESCRIPTION

[0008] The invention discloses a novel use of quinolone compounds as fungicides in preventing and controlling bacterial diseases of crops. The quinolone compounds are fleroxacin, enoxacin, gatifloxacin, moxifloxacin hydrochloride, enrofloxacin, marbofloxacin, norfloxacin, monofloxacin mesylate, prulifloxacin, banofloxacin, pazufloxacin mesylate, pipemidic acid, sparfloxacin, difloxacin hydrochloride, lomefloxacin hydrochloride, pefloxacin, tosufloxacin mesylate, cinoxacin, garefoxacin, besifloxacin hydrochloride, ofloxacin, nalidixic acid, clinafloxacin and sitafloxacin, which can prevent and control bacterial diseases of crops caused by citrus canker bacteria.

[0009] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention. However, the content of the present invention is not limited to the scope described in the embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the protection scope of the present invention.

[0010] Example: Indoor antibacterial activity determination and results

[0011] The microbroth dilution method was used: the citrus canker bacteria were inoculated into 20 mL of MH medium, and then incubated in a constant temperature shaker at 37°C for 12 h at a speed of 150 rpm. An appropriate amount of bacterial culture solution was taken and the absorbance at 600 nm was measured using an ELISA reader. The culture solution without bacteria was used as a blank control. The OD value was calculated based on the OD value. 600 0.1 is equivalent to a concentration of 1×10 8 cfu / mL, and the bacterial suspension was diluted with MH medium to a concentration of 1×10 6 cfu / mL of bacterial solution for later use.

[0012] Use a spray gun to draw 50 μL of diluted bacterial solution into a 96-well plate, and then add 50 μL of compound solution in turn. The blank control is to add the same volume of PBS solution. Set 3 replicates for each concentration. After the sample is placed in a constant temperature incubator at 28°C for 24 hours, its OD value at 600nm is measured, and the inhibition rate is calculated by the following formula, and the inhibition concentration EC is calculated using SPSS software. 50 The inhibitory effects of 25 quinolone compounds on citrus canker bacteria were determined, and the results are shown in Table 1.

[0013]

[0014] Table 1. Inhibitory activity of quinolones against Xanthomonas citri var.

[0015]

[0016] From the test results in Table 1, it can be seen that most of the quinolone compounds involved in the present invention exhibit excellent bactericidal activity. In particular, gatifloxacin, moxifloxacin hydrochloride, monofloxacin mesylate, sparfloxacin, tosufloxacin mesylate, clinafloxacin, and sitafloxacin have the strongest antibacterial activity against citrus canker bacteria, and their EC 50 The values ​​were 0.27, 0.14, 0.29, 0.15, 0.14, 0.09, and 0.11 μg / mL, respectively. In summary, the quinolone compounds of the present invention exhibit significant inhibitory activity against the plant bacterial disease citrus canker, and can be used in the prevention and treatment of crop diseases.

Claims

1. Use of quinolone compounds in preventing and treating plant bacterial diseases such as citrus canker, characterized in that: The quinolone compound is moxifloxacin hydrochloride.

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