Study On The Mechanism Of Sulfonamide Compound SYAUP-CN-26 On Botrytis Cinerea

Sulfonamides,as a research hotspot in the world today,are widely used in the agricultural to control the harm of harmful organisms in the field.In this laboratory,a series of sulfonamide compounds were synthesized and screened to obtain the test compound(1S,2R-((3-bromophenethyl)amino)-N-(4-chloro-2-(trifluoromethyl)phenyl)cyclohexane-1-sulfon amide)(code:SYAUP-CN-26).The resluts of this study have shown that SYAUP-CN26 has a very excellent antifungal activity against Botrytis cinerea.Because of its novel structure,the mechanism of SYAUP-CN-26 is different from fungicides which were commonly used in the market for the prevention and treatment of gray mold.It has the potential to be a lead compound for fungicides against gray mold.In order to further explore the mechanism of SYAUP-CN-26 on Botrytis cinerea,this paper studied its effects on the substance synthesis ability,respiratory metabolic capacity,and mitochondrial function of Botrytis cinerea,respectively.And determined the effect of SYAUP-CN-26 at three concentrations EC50(1.823 mg/L),EC90(19.263 mg/L)and MIC(79.754 mg/L)on the cell wall,cell membrane,protein,reducing sugar,respiratory metabolism,ATP content and mitochondrial function of Botrytis cinerea.The results are as follows:Through the determination of the chitinase activity of Botrytis cinerea,it was found that the chitinase activity remained stable in each concentration-treated group throughout the entire measurement interval,and the difference was not significant compared with the chitinase activity of the control group.The results indicated that the compound SYAUP-CN-26 has no inhibitory effect on the cell wall of Botrytis cinerea.The content of reducing sugar in the cells of Botrytis cinerea was inhibited after 24 h treatment with 79.754 mg/L of SYAUP-CN-26,which was lower than that of the control group,while the content of reducing sugar in the extracellular was remained stable throughout the measurement time range,this showed that the compound SYAUP-CN-26 could inhibit the synthesis of reducing sugars at a certain concentration.With the increase of the concentration of the compound SYAUP-CN-26 and the extension of the treatment time,the content of soluble protein was inhibited and showed a downward trend.And the content of ergosterol was inhibited after treatment with SYAUP-CN-26 for 12 hours.After treatment with compound SYAUP-CN-26,the cell conductivity,malondialdehyde(MDA),extracellular DNA and RNA contents of the treatment groups with each concentration showed an upward trend.The above results indicated that the compound SYAUP-CN-26 has an inhibitory effect on the cell membrane of Botrytis cinerea,and weaken the cell’s ability to synthesize substances.The effect of the compound SYAUP-CN-26 on the respiration rate of Botrytis cinerea was measured by the Liquid-Phase Oxygen Measurement.After 24 hours of treatment with three concentrations of the compound SYAUP-CN-26,the respiratory rate inhibition of Botrytis cinerea was 54.74%,76.89 % and 82.48%,severely inhibited respiratory metabolism.For different ages of Botrytis cinerea,the degree of inhibition decreased slightly with the increase of Botrytis cinerea age.And the superposition rate of the compound SYAUP-CN-26 with malonic acid,Iodine acetic acid,and sodium phosphate three typical respiratory inhibitors indicated that the tricarboxylic acid cycle pathway(TCA)of Botrytis cinerea was affected.In addition,the ATP content was severely reduced.The activity of mitochondrial complexesⅠ~Ⅴ was measured by the kit,and the results showed that the activities of the five complexes were all inhibited to varying degrees.The activity of complexesⅠ,complex Ⅱ and complex Ⅳ was most significantly inhibited,and the inhibition of complex Ⅱ activity was not affected by the concentration.And the activity of complex Ⅲ was less inhibited,which remained basically stable.The activity of complex Ⅴ was also inhibited by the compound.In addition,the openness of the mitochondrial membrane permeability transport pore(MPTP)was increased.In summary,the compound SYAUP-CN-26 could inhibit the synthesis of reducing sugars and soluble proteins of Botrytis cinerea and change the permeability of the cell membrane.But more importantly,the compound SYAUP-CN-26 inhibited the activity of the mitochondrial respiratory chain complex of Botrytis cinerea,which inhibited its respiratory metabolism and ATP synthesis.