Genetic Engineering Research Center, College of Bioengineering, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides and Key Lab. of Functional Gene and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.
J Invertebr Pathol. 2011 Sep;108(1):7-12. doi: 10.1016/j.jip.2011.06.002. Epub 2011 Jun 12.
Phosphomannose isomerase (PMI) catalyzes the reversible interconversion of fructose 6-phosphate (Fru-6-P) and mannose 6-phosphate (Man-6-P), providing a link between glycolysis and the mannose metabolic pathway. In this study, we identified pmi gene (Mapmi) from the entomopathogenic fungus, Metarhizium acridum, and analyzed its functions using RNA interference (RNAi). Amending the growth medium with cell stress chemicals significantly reduced growth, conidial production and percent germination in Mapmi-RNAi mutant strain, compared to the wild-type strain. Growth of RNAi mutant was lower than the wild type strain with glucose or fructose as sole carbon source. RNAi mutant exhibited a normal growth phenotype with mannose at low concentrations, while trace or high concentration of mannose was more negatively impacted the growth of RNAi mutant than the wild type strain. Infection with Mapmi-RNAi mutant against Locusta migratoria manilensis (Meyen) led to a significantly reduced virulence compared to infection with the wild-type strain. These results suggest that Mapmi plays essential roles in stress tolerance and pathogenicity of M. acridum.
磷酸甘露糖异构酶（PMI）催化果糖 6-磷酸（Fru-6-P）和甘露糖 6-磷酸（Man-6-P）的可逆转化，为糖酵解和甘露糖代谢途径之间提供了联系。在这项研究中，我们从昆虫病原真菌玫烟色棒束孢中鉴定出了 pmi 基因（Mapmi），并通过 RNA 干扰（RNAi）分析了其功能。与野生型菌株相比，在添加细胞应激化学品的培养基中，Mapmi-RNAi 突变菌株的生长、分生孢子产生和萌发率显著降低。与葡萄糖或果糖作为唯一碳源相比，RNAi 突变体的生长速度低于野生型菌株。RNAi 突变体在低浓度下表现出正常的生长表型，但痕量或高浓度的甘露糖对 RNAi 突变体的生长影响比对野生型菌株更大。与野生型菌株相比，用 Mapmi-RNAi 突变体感染东亚飞蝗导致毒力显著降低。这些结果表明 Mapmi 在玫烟色棒束孢的应激耐受和致病性中发挥重要作用。
