小麦隐匿柄锈菌与小麦互作不同阶段的基因差异表达分析

Anslysis of differentially expressed genes in Puccina triticina at different stages of the interaction between wheat and wheat leaf rust pathogen

摘要:

【目的】小麦叶锈病是影响小麦生产主要病害之一，其病原菌新小种的出现和劣势小种上升为优势小种导致抗病品种的抗病性不断被克服。小麦隐匿柄锈菌与小麦互作不同阶段差异表达谱分析对于揭示该病菌致病的分子机制，进而有效防控小麦叶锈病具有重要意义。【方法】利用转录组分析小麦隐匿柄锈菌致病生理小种与感叶锈病小麦品种MuTcLr19亲和互作后期（6 d）与互作早期（6、12、24 h）差异基因表达谱，实验以亲和互作早期（MIQ）为对照组，亲和互作6 d（MI6d）为实验组。【结果】测试结果表明，上调表达基因19 275个，下调表达基因4 548个。GO富集分析发现，差异表达基因功能主要涉及代谢过程、催化活性、细胞过程、单组织过程、细胞内的细胞器、核酸结合和水解酶活性、氮化合物代谢、细胞代谢过程等。KEGG分析发现，差异表达基因共参与了109条通路，筛选出囊泡运输中SNARE的相互作用通路、卟啉和叶绿素代谢通路及ABC转运通路和病原菌的致病相关。随机取来自这3条通路的5个基因进行荧光定量分析，结果表达趋势与转录组表达谱结果一致。【结论】小麦隐匿柄锈菌在早期表达的差异基因注释到的功能更多与小麦隐匿柄锈菌致病性有关，后期表达的差异基因大部分与小麦隐匿柄锈菌的生长代谢有关，早期与后期表达的基因存在明显的差异。研究结果为今后开展小麦隐匿柄锈菌致病机制研究奠定了基础。

Abstract:

[Objective] Wheat leaf rust caused by Puccina triticina (Pt) is one of the most damaging diseases in wheat production. The emergence of new races of Pt and the rise of inferior races led to the continuous overcoming of the resistance of varieties. Therefore, the analysis of deferentially expressed genes of Pt in different infection stages is of great significance to reveal the pathogenic molecular mechanism of wheat leaf rust.[Methods] In this study, deferentially expression genes in the interaction of pathogenic type THTT of Pt and the susceptible wheat (MU19) at the early interaction (inoculated after 6 h, 12 h, 24 h) and a later stage (6 d after inoculation) were analyzed with the RNA-seq transcriptome analysis method. Taking the early stage (MIQ) as the control group, and 6 d of affinity interaction (MI6d) as the experimental group to analysis the differentially expressed genes.[Results] 19 275 unigenes were up-regulated and 4 548 genes were down-regulated at 6 d. GO enrichment analysis found that the function of the deferentially expressed unigenes were mainly involved in metabolic processes of catalytic activities, cellular formation processes, single-tissue synthesis, intracellular organelle formation, nucleic acid binding and hydrolase activities, nitrogen compound metabolism, cellular metabolic process, etc. KEGG analysis showed that differentially expressed genes were involved in 109 pathways. The SNARE interaction pathway, porphyrin and chlorophyll metabolism pathway and ABC transporter pathway in vesicle transport were found to be related with pathogenicity of the Pt. Five genes were randomly selected from these three pathways for qRT-PCR analysis, and their expression trends were shown consistent with the results of transcriptome expression profile.[Conclusion] The function of the differently expressed genes at the early stages of inoculation may be related to the pathogenicity of the pathogen, while most of the differently expressed genes in the later stage are related to the growth and metabolism in the pathogen. There are obvious differences between the genes expressed at early and later stages. These results are important and provide fundamental references for future studies on the pathogenic mechanism of wheat leaf rust.