为有效利用自然界广泛存在的细菌天敌-噬菌体来生态调控植物细菌病害，迫切需要搞清楚噬菌体复杂且多样化的裂解机制。申请者团队前期国内外首次分离获得水稻细菌性褐条病菌的烈性噬菌体AP1，全基因组测定及生信和生物学分析鉴定出一种具有新裂解机制的穿孔素-内溶素双组分系统，其无信号肽的内溶素单独具溶菌功能，且与不同于目前报道类型的穿孔素互作。本申请项目拟首先分离、纯化和特征化噬菌体AP1的穿孔素和内溶素，明确它们的生物学功能；然后利用全长基因的截短体分别构建穿孔素和内溶素的突变体并比较其和野生型的裂解能力，明确它们在噬菌体AP1裂解水稻褐条病菌中的功能；最后在生物学、细胞学和共表达水平上鉴定穿孔素和内溶素在裂解中的协同增效，结合pull down和BiFC互作分析，以最终明确噬菌体AP1新穿孔素-内溶素双组分系统裂解水稻褐条病菌的机制，为更好地利用这一新裂解系统来生物防治植物细菌病害提供理论依据。

In order to effectively control plant bacterial diseases using the bacteriophages that widely distributed in nature, it is very necessary to make clear the complex and diverse mechanism of bacteriophage lysis. The applicants firstly isolated and obtained lytic bacteriophage AP1 of rice bacterial brown stripe pathogen in the world, furthermore, a new two-component lysis system was successfully identified through complete genome sequencing, bioinformatics analyses and biological test. Prokaryotic expression revealed the lytic function of endolysin without signal peptide and the synergistic effect of holin, while the interaction between them was justified by bacterial two-hybrid analysis. The aim of this project is to clarify their biological function by isolating, purifying and characterizing the holin and endolysin of bacteriophage AP1; and then elucidate the role of holin and endolysin in the lysis of Acidovorax oryzae by comparing the lysis ability between the wild type and the constructed mutants; and finally determinate the mechanism of the new two-component system in the lysis of Acidovorax oryzae by identifying their synergistic effects in biology, cytology and co-expression levels, in combination with the interaction based on the analysis of BiFC and pull down. The result of this study will provide a theoretical basis for the use of the new lysis system in biological control of plant bacterial diseases.