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

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.