盐胁迫对胶霉毒素生物合成基因gliT表达的影响

Effects of salt stress on the expression of gliotoxin biosynthesis gene gliT

从烟曲霉菌株F3中克隆得到gliT基因(胶霉毒素生物合成基因簇成员之一),其编码产物GliT是一个假定的硫氧还蛋白还原酶,含有保守的Pyr_redox和TrxB结构域,与来自于烟曲酶菌株Af293的GliT在氨基酸水平上的同源性高达97%。不同盐浓度培养条件下,烟曲霉菌株F3中gliT基因的表达变化与发酵液中胶霉毒素的含量变化之间存在着明显的相关性,均在盐浓度70 g/L培养条件下达到峰值,提示gliT基因在胶霉毒素生物合成过程中的作用可能与盐胁迫有关。

gliT is a member of gliotoxin biosynthesis gene cluster.To know its role in the biosynthesis of gliotoxin,a gliT gene was cloned from Aspergillus fumigatus strain F3.This gene is deduced to encode a putative thioredoxin reductase,which shares about 97% homology with the GliT from A.fumigatus strain Af293 and contains the conserved domains of Pyr_redox and TrxB.The expression levels of this gene showed a significant positive correlation with the gliotoxin contents in the fermentation broth of A.fumigatus strain F3 under conditions of increasing salinity,and reached their peaks under 70 g/L salinity.These results showed that the role of gliT on the biosynthesis of gliotoxin may be related to salt（or salinity） stresses.