串珠镰刀菌伏马菌素产毒株分子遗传学研究进展

Molecular genetics on Fumonisin-producing strains of Fusarium verticillioides

伏马菌素是一组主要由串珠镰刀菌产生的真菌毒素。伏马菌素B1对某些牲畜有急性毒性及潜在的致癌性 ,如引起马脑白质软化症、猪肺水肿或大鼠肝癌 ,流行病学研究认为其与人类食管癌的高发有关。目前国际上对伏马菌素的研究已经深入到分子水平 ,通过对串珠镰刀菌伏马菌素产毒株的遗传学研究 ,鉴定了 4个与伏马菌素生物合成相关的基因fum1、fum2、fum3和fum4及由 4个基因fum6、fum7、fum8和fum9所组成的伏马菌素生物合成协同调节基因蔟。应用简并PKS引物 ,进行PCR扩增 ,证明fum5为伏马菌素生物合成所必需的多酮肽合成酶基因。并对串珠镰刀菌伏马菌素产毒株进行了分子生物学研究。还通过转基因技术来控制串珠镰刀菌感染及伏马菌素生成 ,以减少对人、动物健康及食品安全的危害。

Fumonisins are a group of mycotoxins produced by Fus arium verticillioides (synonym Fusarium moniliforme Sheldon). Fumonisin B1 has acute toxicity and potential carcinogenicity to some animals, causing leuko encephalomalacia in horses, porcine pulmonary edema (PPE) and liver cancer in ra ts. It was considered to be epidemiologically associated with high incidence of Human Esophageal Cancer (EC) in human. At present, the study on fumonisins has r eached molecular levels. 4 clustered and coregulated genes fum1, fum2, fum3 an d fum4 associated with Fumonisin biosynthesis were identified through genetics study on Fumonisin producing strains of Fusarium verticillioides. The resul t of PCR with degenerate primers based on polyketide synthase (PKS) gene proved that fum5 was PKS gene required for fumonisin biosynthesis. Study on molecu lar biology of Fumonisin producing strains was also performed. Furthermore, tran sgenic strategies were used for ear mold resistance to Fusarium and reducing Fum onisin contamination in plants, to decrease the hazard to the health of both hum an and animals, as well as food safety.