水稻纹枯病菌毒素提纯及其组分初步分析

Separation,purification,and preliminary composition analysis of the toxin of Rhizoctonia solani,the pathogen of rice sheath blight

用不同方法提取的水稻纹枯病菌(Rhizoctonia solani)毒素活性有显著差异,但紫外扫描图谱(最大吸收波长约220 nm)相似,表明其可能为同类物质。其中,以乙醚萃取法获得的粗毒素对水稻胚根伸长的抑制率最高,达94.63%,接种水稻叶鞘后可产生典型的纹枯病症状。将乙醚萃取法提取的粗毒素经2次Sephadex G-75凝胶柱层析纯化,收集活性峰而获得精毒素。薄层色谱(TLC)分析表明,该毒素为糖类物质。高效液相色谱(HPLC)检测显示,该毒素至少有4个特殊吸收峰,表明可能有4种组分。经红外光谱(IR)分析,该毒素含有N-H(或O-H)、C=O、C-N(或C-O)等基团。气质联用(GC-MS)检测表明,该毒素含有葡萄糖、N-乙酰氨基甘露糖和蔗糖,而不含苯甲酸、苯乙酸及其衍生物。

Crude toxin, extracted from the culture filter of Rhizoctonia solani with different methods was different in the biological activity but had similar UV absorption spectra with the maximum absorptive wave length of about 220 nm, which indicated that they may have similar chenmical composition. The crude toxin extracted with ether had the strongest inhibition to rice radiele growth with the inhibition rate of 94.63% and could induce the characteristic symptoms of rice sheath blight. The crude toxin was continuously separated and purified by Sephadex G-75 silica gel column chromatography for two times, and the active eluates were collected and called the pure toxin. On the basis of thin layer chromatogra phy （TLC） analysis, the toxin was carbohydrate. By high performance liquid chromatography （HPLC） analysis, the toxin had four specific absorption peaks at least, which indicated that it could contain four components. Through infrared spectrum （IR） determination, the toxin could have N-H （or O-H）, C=O, C-N （or C-O） signals. According to gas chromatography mass spectrometry （GC-MS）, the toxin contained glucose, N-acetyl-mannose and sucrose, but no benzoic acid, phenylacetic acid and their ramifications.