背景:Macrophominaphaseolina是一种病原体,可引起机会性疾病,该疾病通过土壤和种子传播,并影响500多种不同的植物物种,像水果,树木,行作物。霉菌毒素,例如phaseolinicacid,和phaseolinone,在以前的研究中,由M.phaseolina分离株产生;然而,这些霉菌毒素的产生似乎因宿主和地区而异。
结果:在这项研究中,从腐烂的木薯块茎中分离出菜豆巨噬细胞菌株3A,并使用内部转录间隔区序列的分析进行鉴定。在25°C下将分离物接种在新鲜的健康木薯块茎上,并监测块茎腐烂潜力4周。用设计的引物测定毒力基因MPH_06603、MPH_06955和MPH_01521,和次级代谢产物通过FTIR和GCMS进行表征。从实验的第2周开始观察到腐烂的块茎效应,块茎严重腐烂和体重减轻。PCR显示存在MPH_06603毒力基因。GCMS显示N-甲基新戊酰胺(115.0m/z),丁烷,1,4-二甲氧基-(119.0m/z),5-羟甲基糠醛(126.0m/z)是病原体产生的主要代谢产物。代谢物中的化合物抑制CYP3A4酶,引起眼睛刺激,和人类以太相关基因抑制。
结论:这项研究表明,菜籽是木薯块茎腐烂的原因,导致农产品产量降低。产生的代谢物是有毒的,对人类食用不安全。建议农民销毁受这种病原体影响的木薯,以防止其对人类和动物的毒性作用。
BACKGROUND: Macrophomina phaseolina is a pathogen that causes an opportunistic disease that spreads by soil and seeds and affects more than 500 different plant species, like fruits, trees, and row crops. Mycotoxins, such as phaseolinic acid, and phaseolinone, are produced by M. phaseolina isolates in previous investigations; however, the production of these mycotoxins seems to vary depending on the host and the region.
RESULTS: In this study, Macrophomina phaseolina strain 3 A was isolated from rotten cassava tuber and identified using the analysis of the sequences of the internal transcribed spacer region. The isolate was inoculated on a fresh healthy cassava tuber at 25 °C and tuber-rotting potential was monitored for 4 weeks. Virulence genes MPH_06603, MPH_06955, and MPH_01521 were determined with designed primers, and secondary metabolites were characterized by FTIR and GCMS. The rotten tuber effect was observed from the 2nd week of the experiment with severe tuber rot and weight reduction. The PCR showed the presence of MPH_06603 virulence gene. The GCMS showed N-Methylpivalamide (115.0 m/z), Butane, 1,4-dimethoxy- (119.0 m/z), and 5-Hydroxymethylfurfural (126.0 m/z) were the predominant metabolites produced by the pathogen. The compounds in the metabolites inhibit CYP3A4 enzymes, cause eye irritation, and Human Ether-a-go-go-related gene inhibition.
CONCLUSIONS: This study revealed that M. phaseolina was responsible for the cassava tuber rot which leads to a lower yield of farm produce. The metabolites produced are toxic and unsafe for human consumption. It is suggested that farmers should destroy any cassava affected by this pathogen to prevent its toxic effects on humans and animals.