大黄鱼是我国海水养殖产量最大的鱼类，杀香鱼假单胞菌是养殖大黄鱼危害最大的病害之一的“内脏白点病”的病原，secY基因是杀香鱼假单胞菌重要的毒力调控基因。本项目拟在前期研究的基础上，构建杀香鱼假单胞菌的secY过表达菌株，并与野生株、前期构建的稳定沉默突变株一起，综合应用基因稳定沉默技术、dual RNA-seq、iTRAQ、Western blot、免疫荧光等技术，从secY介导杀香鱼假单胞菌分泌蛋白特性与毒力、secY介导杀香鱼假单胞菌毒力的分子机制、secY介导的杀香鱼假单胞菌与宿主大黄鱼相互的分子机制等三个层次来系统开展secY基因的致病机制研究。本项目的研究结果将可揭示secY这个重要的毒力调控基因的致病功能，有助于深化对杀香鱼假单胞菌致病机理的认知，也有助于增进对杀香鱼假单胞菌与大黄鱼互作的认识。

Large yellow croaker is the marine-cultured fish with the largest annual output in China. Pseudomonas plecoglossicida is the pathogen of "visceral white spot disease", which is one of the most harmful diseases in cultured large yellow croaker. secY gene is an important virulence regulatory gene of P. plecoglossicida. In view of the above factors, the pathogenesis of secY gene is planed to be studied in this project based on the previous study. The over-expression strain of secY of P. plecoglossicida will be constructed first and be used in the studies on the pathogenesis of secY gene, together with wild strain and stable silencing mutants constructed in the early stage. The gene stable silencing technique, dual RNA-seq, iTRAQ, Western blot, Immunofluorescence and other techniques will be applicated synthetic. The studies on the pathogenesis of secY gene will be carried out from the following three levels: the characteristics and virulence of the secY-mediated secreted protein of P. plecoglossicida; molecular mechanism of secY-mediated virulence of P. plecoglossicida; molecular mechanism of secY-mediated pathogen-host interactions between P. plecoglossicida and large yellow croaker. The results of the studues of this project will reveal the pathogenic function of secY (an important virulence control gene), which can help to deepen the cognition of the pathogenic mechanism of the P. plecoglossicida, and also help to enhance the understanding of the interactions between P. plecoglossicida and large yellow croaker.