拟枝孢镰孢Fspgp2基因负调控T-2毒素产量

Fusarium sporotrichioides Fspgp2 gene involved in negative control of T-2 toxin production

T-2毒素(T-2 toxin)是单端孢霉烯族毒素中细胞毒性最强的一种,广泛污染粮食作物,在世界多国的大麦、黑麦、燕麦、玉米等样品中均有污染报道,威胁粮食安全与人畜健康。目前T-2毒素标准物质主要是从产毒菌培养物中提取纯化获得,产率较低,主要依赖进口,货期长、价格昂贵。本研究筛选了一株产T-2毒素的拟枝孢镰孢Fsp1,通过基因敲除策略构建了T-2毒素负调控元件Fspgp2的敲除突变体,突变体的菌丝生长及产孢量与野生型菌株相比无显著差异,但其T-2毒素产量显著提高,在大米培养基中产量为421.98mg/kg,为构建T-2毒素宏量制备纯化技术提供菌源基础,对于粮食中T-2毒素污染风险的持续监测和控制技术的研发意义重大。

T-2 toxin is the most cytotoxic among the type A trichothecene toxins,which is widely contaminated in grain samples,and has been reported in barley,rye,oat,and corn samples in many countries in the world,threatening grain safety and animal health.At present,T-2 toxin standard material is mainly extracted from the culture of toxigenic fungi,and the yield of toxin is low.In China,the supply of the toxin mainly depends on imports with long delivery time and high price.In this study,a T-2-toxin-producing strain Fusarium sporotrichioides Fspl was isolated,and the deletion mutant of negative regulatory element Fspgp2 of T-2 toxin was constructed by gene knockout strategy.Subsequent verification results showed that the mycelial growth and conidial production of the mutant appeared to be undifferentiated as compared with that of the wild-type strain,and the production of T-2 toxin of the mutant was significantly increased(421.98 mg/kg in rice culture).The mutant hopefully could provide strain source for preparation and purification of T-2 toxin on a large scale,which is of great significance for development of monitoring and controlling T-2 toxin contamination in grains.