Puccinia triticina pathotypes- THTT and THTS display complex transcript profiles on wheat cultiver Thatcher
Abstract Background: Wheat leaf rust is an important disease worldwide. Understanding the Puccinia triticina f. sp. tritici (Pt) pathogenic molecular mechanism and the inconstant toxic region is critical for managing the disease. The present study aimed to analyze pathogenic divergence between Pt isolates.Results: Total RNA was extracted from wheat cultiver Thatcher infected by two Pt isolates, Tc361_1 (THTT) and Tc284_2 (THTS) at 144 hours post inoculation (hpi). The mRNA was then sequenced, and a total of 2,784 differentially expressed genes (DEGs) were detected. Forty-five genes were specifically expressed in THTT; these genes included transcription initiation factors and genes with transmembrane transporter activity and other genes. Twenty-six genes were specifically expressed in THTS, including genes with GTPase activity, ABC transporter genes and other genes. Fifty-four differentially expressed candidate effectors were screened from the two isolates. Two candidate effectors were chosen and validated on tobacco, and the results showed that they could inhibit necrosis induced by Bax. qRT-PCR of 12 significant DEGs was carried out to validate the results are similar to that of RNA-seq at 144 hpi, to show the expression levels of these DEGs in the early stage and to elucidate the differences in expression between the two Pt pathotypes.Conclusion: The results obtained in this study showed that the two pathtypes of THTT and THTS although contribute similar virulence to wheat, there are a large number of genes participate in the interaction with susceptible wheat cultivar Thatcher, and revealed the pathgenicity of rust is very complicated.