Evaluation Of Berberine As A Natural Compound To Inhibit Monilinia Fructicola

Peach brown rot is one of the most serious diseases in peachproduction,and is caused by the fungus Monilinia fructicola, which infects theflowers, leaves, and fruits. This disease causes considerable economic loss inpeach-producing areas. In the past half century, scientists were alwayssearching for fungicides with high efficiency, low toxicity and reduceddrug-resistance by M. fructicola. As a plant-derived natural compound,berberine is benign to the enviromment and has been verified to be able tohighly inhibit the growth of M. fructicola. Up to now, its research is still at thepreliminary stage, and its evaluation as a novle fungicide is required forcontrolling peach brown rot. To boost the application of berberine inproduction, we compared the efficacy of berberine and four otherrepresentative fungicides. Then we evaluated the compound pesticideconsisting of berberine and carbendazim, and finally explored the molecularmechanism of M. fructicola response to berberine stress.In drug effect comparison experiment, all four fungicides includingcarbendazim, tebuconazole, fludioxonil, and azoxystrobin showed significantinhibitory activity against M. fructicola, and carbendazim domenstrated the highest antibacterial activity with MIC of0.05g/mL and EC50of merely0.0115g/mL. Compared with other fungicides, berberine, although not asefficient as carbendazim and fludioxonil, was comparable to tebuconazole andwas superior to azoxystrobin.The above study revealed the much higher activity of carbendazim thanthat of other fungicides. Thus, we performed ccomplex test with berberine andcarbendazim by using a co-toxicity factor method aiming at evaluating theactivity of complex pesticide. In pesticide compound antibacterial test, theequivalent linear method was used to design the complex ratio, it was foundthat when berberine and carbendazim the optimal complex concentration ratiois3657:1. The result indicated that when less carbendazim was added,synergistic effect emerged, meaning the avoidance of drug resistance.Finally, this study on drug-resistant mechanism at molecular level wasperformed via reverse transcription PCR to uncover the potential target ofberberine on M. fructicola. Based on previous work, this study focused ontubulin gene (β-tub) cutinase gene (cut-1) cytochrome P450sterol14α-demethylase gene (Mfcyp51), ABC transporter gene (Mfabc1), alternativeoxidase gene (Mfaox1)and two component histidine kinase (Mfos1). Themodel of M. fructicola response to berberine stress was established throughmultiple generation culture. Compared with the primary generation of M.fructicola, M. fructicola of eighth generation domenstrated difference in theexpression of cut1Mfcyp51and Mfabc1, while no difference inβ-tub Mfaox1and Mfos1. This preliminary study concerning molecular mechanismhas proved that berberine can make overexpression or mutan these genes ofM.fructicola to avoid the sterilization effect of berberine. These results supportthe promising application of berberine as a fungicide for inhibition of M.fructicola.