2M3P灵菌红素对植物病原菌的抑制作用及其机制

Inhibitory Effect and Mechanism of 2-Methyl-3-pentyl prodigiosin(2M3PPG) producing by Serratia marcescens XJU-PA-6 against Crop pathogens

本研究以从中国新疆塔尔巴哈台山上的有毒植物——块根芍药(Paeonia anomala)中分选获得一株产红色素的植物内生菌Serratia marcescens XJU-PA-6为研究对象,首先通过琼脂扩散法将Serratia marcescens XJUPA-6的发酵获得的色素粗提物分别和11种常见作物病原真菌进行拮抗实验,结果表明,色素粗提物对黄瓜枯萎病菌、番茄灰霉病菌、油菜菌核病菌、棉花黄萎病菌、西瓜枯萎病菌和苹果斑点落叶病菌均有较强的抑菌作用,其中对苹果斑点落叶病菌的抑菌作用为最稳定;然后,采用紫外光谱、核磁共振氢谱碳谱分析及GC分析确认XJU-PA-6所产生的红色素为2-甲基-3-戊基灵菌红素(2M3PPG);最后结合扫描电镜、透射电镜和气质联用技术,通过分析发现,2M3PPG可通过抑制苹果斑点落叶病菌中14-α-去甲基化酶活性,来抑制真菌细胞膜上重要成分——麦角固醇的生物合成,从而造成真菌细胞膜中甾醇含量的降低,进而造成细胞膜结构和功能消失,最终导致真菌死亡。本研究结果初步证明,2M3PPG在生物农药方面具有较好地应用潜力。

Endogenous bacterium Serratia marcescens XJU-PA-6 isolated from Paeonia anomala(grown in Tarbarha Taishan,Xinjiang),which can produce haematochrom,was used in this work.Firstly,haematochrom was isolated from the broth of XJU-PA-6 using fermentation method.And then the antagonistic effect of isolated haematochrom against 11 common crop pathogenic fungi was explored with agar plate diffusion method.The results showed that haematochrom produced by S.marcescens XJU-PA-6 can strongly against Fusarium oxysporum f.Sp,Alternaria mali,Botrytis cinerea,Sclerotinia sclerotiorum,Verticillium dahliae and Fusarium oxysporum f.sp.niveum,especially for Verticillium dahlia.Following,the haematochrom producing by S.marcescens XJU-PA-6 was identified as 2-methyl-3-pentylcitamin(2M3PPG)by UV spectroscopy,nuclear magnetic resonance spectroscopy(NMR)and GC-MS.Also,the antigonitic michanisms of 2M3PPG to Verticillium dahliae was carried out using scanning electron microscopy(SEM),transmission electron microscopy(TEM)and GS-MS analysis,the results revealed 2M3PPG can inhibit the biosynthesis of erythropoietin,this event probably happened via inhibiting the activity of 14-α-demethylase in Verticillium dahlia.The results of this work showed that 2M3PPG has a very good potential application as biopesticide.