Submitted to: Journal of Genetics and Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2011
Publication Date: 7/23/2011
Citation: Huang, X., Chen, X., Coram, T., Wang, M., Kang, Z. 2011. Gene expression profiling of Puccinia striiformis f. sp. tritici during development reveals a highly dynamic transcriptome. Journal of Genetics and Genomics. 38:357-371. Interpretive Summary: The stripe rust fungus causes one of the most important diseases of wheat worldwide. However, little is known about expression patterns of genes related to the infection process and sporulation of the pathogen. In this study, a custom microarray was constructed and utilized to determine gene expression patterns from the pathogen during the infection process and sporulation. Microarray analysis was conducted by hybridizing with cDNA from urediniospores, germinated urediniospores, and inoculated wheat leaves sampled at various time points after inoculation. From a total of 442 genes tested, 55 genes were differentially induced during the infection process in a compatible interaction and 17 genes in an incompatible interaction. These genes were charcatreized into various groups according to their expression patterns during the infection process, from which their involvement in pathogenicity/virulence and reproduction were derived. The study demonstrates that the microarray technology is useful to identify pathogen genes involved in the host-pathogen interactions.
Technical Abstract: Puccinia striiformis f. sp. tritici (Pst) causes stripe rust, one of the most important diseases of wheat worldwide. cDNA libraries had been constructed from urediniospores, germinated urediniospores and haustoria. However, little is known about the expression patterns of the genes related to the infection process and sporulation of the pathogen. In this study, a custom oligonucleotide microarray was constructed using sequences of 442 gene transcripts selected from Pst cDNA libraries. The expression patterns of the genes were determined by hybridizing the microarray with cDNA from Pst in vitro and Pst-infected wheat leaves. The time course study identified 55 transcripts that were differentially expressed during the infection process in a compatible interaction. They were identified to have functions related to the following biological processes, including carbohydrate and lipid metabolism, energy, cell signaling, protein synthesis, cell structure and division. In an incompatible interaction, 17 transcripts of the pathogen were differentially expressed in resistant wheat leaves inoculated with an avirulent Pst race, ten of which had similar expression patterns to those in the compatible interaction. Several candidates for pathogenicity and virulence/avirulence related genes were also identified. The results of quantitative real-time PCR validated the expression patterns of some selected genes. The study demonstrates that the custom oligonucleotide microarray technology is useful to determine the expression patterns of the pathogen genes involved in different types of the hostepathogen interactions and stages of development.