稻瘟菌MgORP1基因敲除突变株的构建及其表型分析

Characterization of oxysterol binding protein homolog MgORP1 in therice blast fungus Magnaporthe grisea

摘要:

【目的】了解稻瘟病菌中氧固醇结合蛋白（oxysterol-binding proteins related proteins，缩写为ORPs）家族成员组成情况，构建MgORP1基因缺失突变株和互补株，对MgORP1基因功能进行初步研究。 【方法】以ORPs家族的典型结构域“ORD”为靶标，对稻瘟病菌基因组数据库进行BlastP搜索。通过同源重组的策略，构建MgORP1基因缺失突变体，再通过重新导入该基因全长片段获得互补株。然后对野生型、突变体和互补株进行菌落、分生孢子和附着胞形态或形成情况、以及致病力进行比较分析。【结果】稻瘟病菌基因组中含有6个可能的ORPs族蛋白，其中MgORP1基因的破坏降低了稻瘟菌在完全培养基上的菌落生长速率和产孢量。但对菌丝、分生孢子和附着胞的形态，以及在水稻上的致病力没有明显影响。【结论】MgORP1基因可能与稻瘟病菌的菌落生长和产孢量相关。

Abstract:

[Objective] To study the component of ORPs (Oxysterol-binding proteins-related proteins) family in the rice fungus (Magnaporthe grisea), and the functions of MgORP1 gene with growing development of M. grisea, we constructed two MgORP1 deletion mutants and a complementation mutant. [Methods] All proteins of ORPs have a conserved OSBP-related ligand-binding domain (ORD), which was compared by BLASTP with the sequences of M. grisea genomic DNA published in M.grisea database. One of ORP gene, designated as MgORP1, was deleted by gene replacement and then the phenotypes of △MgORP1 were characterized. [Results] Six putative ORP family proteins have been found in M. grisea, and the growth rate of hyphal colony in complete medium and conidiation of △MgORP1 were lower, whereas the ability of conidia germination, appressoria formation and pathogenicity were normal. [Conclusion] MgORP1 gene of M.grisea was probably involved in colony growth and conidiation.