小麦叶锈菌休眠与萌发夏孢子的差异表达

Analysis of differently expressed genes between resting and germinated urediniospores of wheat leaf rust

摘要:

[目的] 小麦叶锈菌引起的小麦叶锈病是小麦的重要病害之一，孢子萌发和侵入气孔是保证叶锈菌正常侵染寄主的重要前提。本研究旨在研究小麦叶锈菌夏孢子萌发的差异表达特性，为揭示萌发的机制及其与致病的关系提供依据。[方法] 利用小麦叶锈菌致病类型THTT的休眠夏孢子和萌发夏孢子进行RNA-seq分析。[结果] 在萌发夏孢子中筛选出相比休眠夏孢子上调表达的基因为4400个，下调基因5325个。GO富集分析发现，上调差异基因主要涉及细胞进程、有机物代谢、信号传导、单个有机体过程、催化酶活性等；下调基因主要涉及单组织过程、单个有机体细胞过程、有机物代谢过程、催化活性调节等过程。利用KEGG分析发现，差异基因共参与109条通路，从中筛选出两条与孢子萌发相关的通路——丝裂原活化蛋白激酶（MAPK）信号通路和囊泡运输中的SNARE蛋白交流。10个基因的定量分析结果与基因数字表达谱分析结果一致。[结论] 研究获得了叶锈菌孢子萌发及侵入气孔过程中的重要差异基因，研究结果为研究叶锈菌致病机制奠定基础。

关键词:小麦叶锈菌;夏孢子萌发;RNA-seq分析;差异表达;致病性

Abstract:

[Objective] Wheat leaf rust caused by Puccinia triticina (Pt) is one of the most serious wheat diseases worldwide. Urediniospores germination is the premise to ensure the normal infection of leaf rust. Therefore, we studied differential expression characteristics of germinating urediniospores, to provide a basis for revealing the mechanism of germination and its relationship with pathogenesis. [Methods] We used RNA-seq to analyze the differentially expressed genes at resting and germinated urediniospores of THTT pathotype. [Results] We found 4400 up-regulated unigenes and 5325 down-regulated unigenes at germination stage compared with resting urediniospores. GO enrichment analysis showed that the up-regulated differentially unigenes mainly referred to cellular process, the metabolic process of organic matter, signal transduction, single-organism process and catalytic enzyme activity etc. The down-regulated unigenes mainly referred to single-organism process, single-organism cellular process, the metabolic process of organic matter, catalytic activity etc. All differentially expressed unigenes referred to 109 pathways. We choose Mitogen-activated protein kinase (MAPK) signaling pathway and Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) interactions in vesicular transport, which are related with germinating. The results of quantitative analysis of 10 unigenes were consistent with the results of gene digital expression profiling. [Conclusion] The result discovered the significantly differential unigenes in germinated urediniospores and this lay a base for understanding the pathogenic mechanism of Pt.

Key words:Puccinia triticina;urediniospores germination;RNA-seq;differential expression;pathogenicity