Proteome analysis of wheat leaf rust fungus, Puccinia triticina, infection structures enriched for haustoria

Abstract

Puccinia triticina (Pt) is a representative of several cereal-infecting rust fungal pathogens of major economic importance world wide. Upon entry through leaf stomata, these fungi establish intracellular haustoria, crucial feeding structures. We report the first proteome of infection structures from parasitized wheat leaves, enriched for haustoria through filtration and sucrose density centrifugation. 2-D PAGE MS/MS and gel-based LC-MS (GeLC-MS) were used to separate proteins. Generated spectra were compared with a partial proteome predicted from a preliminary Pt genome and generated ESTs, to a comprehensive genome-predicted protein complement from the related wheat stem rust fungus, Puccinia graminis f. sp. tritici (Pgt) and to various plant resources. We identified over 260 fungal proteins, 16 of which matched peptides from Pgt. Based on bioinformatic analyses and/or the presence of a signal peptide, at least 50 proteins were predicted to be secreted. Among those, six have effector protein signatures, some are related and the respective genes of several seem to belong to clusters. Many ribosomal structural proteins, proteins involved in energy, general metabolism and transport were detected. Measuring gene expression over several life cycle stages of ten representative candidates using quantitative RT-PCR, all were shown to be strongly upregulated and four expressed solely upon infection.

Expression profiling of genes involved in the biotrophic colonisation of Coffea arabica leaves by Hemileia vastatrix

“…In H. vastatrix, RTP1 transcripts were highly expressed at all in planta stages and for all compatible interactions surveyed, but not in the in vitro phases. These results are consistent with the expression profiles of orthologous RTP1 genes in M. larici-populina (Duplessis et al 2011b), P. triticina (Song et al 2011) and U. appendiculatus (Puthoff et al 2008). Several RTP gene homologs were detected in a 454-pyrosequencing library of rust infected coffee leaves , indicating their expression in planta.…”

Intact spore MALDI-TOF mass spectrometry and proteomic analysis of Puccinia pathogenic fungi

“…Many of the identified proteins were in accordance with those found in studies on germinating spores [38] or haustoria, which develop during the invasion of the host plant [39]. It is clear that there were host-pathogen interactions present in the given biological system when the studied spores were collected from wheat leaves.…”

Advancing Knowledge on Biology of Rust Fungi Through Genomics

“…Although somewhat out of the scope of this review chapter, the generation of the genomic and transcriptomic data for rust fungi has made feasible interesting and complementary proteomic research. In particular, with respect to revealing potential effector suites produced in P. triticina haustoria, protein identification using generated proteomic spectra was greatly improved because of available comprehensive gene model predictions (Song et al, 2011). In this pathosystem, protein spectra derived from purified haustoria from various virulent and avirulent isolates are currently analysed against generated genomic resources from the corresponding isolates to identify specific effector variants (C. Rampitsch, B.D.…”