Studies on Differential Proteins of Two Forms of Xenorhabdus Nematophilus

Abstract

As an entomopathogenic bacterium, Xenorhabdus nematophila (X. nematophila) can be parasitic in the gut of entomopathogenic nematodes. Compared with the primary form of X. nematophila, its secondary form has more differences in physiological characteristics and metabolic pathways, such as insecticide, antibacterial, anti-cancer and other functions. Many studies about the application of X. nematophila as biological agents in ecological environment have been reported. However, its pathogenic mechanism and specific functional molecules remain to be studied. Therefore, this study is dedicated to research differential proteins between the primary and the secondary bacteria with iTRAQ technique to further explore the functional mechanism and functional proteins of X. nematophila. A total number of 367 differentially expressed proteins were detected with iTRAQ technique. Besides Xenocoumacin and Xnph1 proteins that had been widely studied by some scholars, other specific proteins in primary bacteria excavated are as follows: Xcn and Xnph1 proteins with antibacterial property, proteins related to the attachment of X. nematophila to the host insects including flagellin, fimbrial adaptor, fimbrial adhesion and capsular synthesis regulator component B, glutamate synthase that plays an important role in multiple metabolic pathways in the primary bacteria, multidrug resistance secretion proteins with the property of tumor drug resistance and defense effects against cytotoxic compounds produced by normal cells and malignant cells.