禾谷镰刀菌中磷脂酰肌醇转运蛋白功能分析

磷脂酰肌醇转运蛋白(phosphatidylinositol transfer protein,PITP)保守存在于真核生物中,负责膜系统中磷脂酰肌醇和磷脂酰胆碱的转运,参与胞内的脂类信号调控过程。由禾谷镰刀菌(Fusarium graminearum)引起的小麦赤霉病严重威胁粮食产量和食品安全,而在禾谷镰刀菌的研究中发现磷脂信号网络中的关键元件参与病原菌致病过程的调控。我们利用基因敲除的方法对禾谷镰刀菌中PITP家族的功能进行分析,在禾谷镰刀菌中鉴定了7个PITP蛋白的编码基因,并成功获得了其单敲除突变体。通过表型分析发现,这7个基因的单敲除突变体在营养生长、无性及有性生殖和致病性方面与野生型菌株并无明显差异。研究结果表明:1)禾谷镰刀菌中的PITP基因并不是看家基因;2)不同PITP基因之间可能存在功能冗余;3)丝状真菌中PITP的生理功能与酵母中的PITP存在显著差异。

Functional analysis of phosphatidylinositol transfer proteins in Fusarium graminearum

Phosphatidylinositol transfer protein (PITP), a kind of conserved protein existed in eukaryotes, transfers phosphatidylinositol or phosphatidylcholine between membranes and takes part in cellular lipid signaling events. Fusarium head blight caused by F. graminearum seriously threats grain production and food security. The previous researches demonstrated that the key components of the phospholipids signaling network were involved in the regulation of virulence process in F. graminearum. Therefore, we decided to analyze the function of PITPs in this pathogen using gene deletion method. Finally, seven of PITPs genes were identified and successfully deleted, respectively. The phenotype analysis showed that the single gene deletion mutants for these 7 PITPs exhibited no obvious differences on vegetable growth, asexual and sexual reproduction, and virulence process compared to wild type strain. The above data indicated that 1) PITP genes in F. graminearum are not housekee ping genes; 2) functional redundancy may exist among these genes; 3)biological functions of PITPs in filamentous fungi have great diversity compared with that in yeast.