In-Depth Analysis of the <i>Magnaporthe oryzae</i> Conidial Proteome

The filamentous fungus Magnaporthe oryzae (M. oryzae) is the causative agent of rice blast
disease
and presents a significant threat to worldwide rice production. To
establish the groundwork for future research on the pathogenic development
of M. oryzae, a global proteomic study of conidia
was performed. The filter aided sample preparation method (FASP) and
anion StageTip fractionation combined with long, optimized shallow
210 min nanoLC gradients prior to mass spectrometry analysis on an
Orbitrap XL was applied, which resulted in a doubling of protein identifications
in comparison to our previous GeLC analysis. Herein, we report the
identification of 2912 conidial proteins at a 1% protein false discovery
rate (FDR) and we present the most extensive study performed on M. oryzae conidia to date. A similar distribution between
identified proteins and the predicted proteome was observed when subcellular
localization analysis was performed, suggesting the detected proteins
build a representative portion of the predicted proteome. A higher
percentage of cytoplasmic proteins (associated with translation, energy,
and metabolism) were observed in the conidial proteome relative to
the whole predicted proteome. Conversely, nuclear and extracellular
proteins were less well represented in the conidial proteome. Further
analysis by gene ontology revealed biological insights into identified
proteins important for central metabolic processes and the physiology
of conidia.