Phytophthora detection in planta

Phytophthora is arguably one of the most damaging genera of plant pathogens and is recognized as a threat to a broad spectrum of plant species. This pathogen is well suited to transmission via the international plant trade, and globalization has been promoting its spread since the 19th century. Early detection is essential for its effective control and of paramount importance in reducing the economic and ecological impact. The increasing sensitivity of the mass spectrometry-based detection indicates that a protein-based analysis may soon complement routine molecular techniques for pathogen detection. Here, a shotgun proteomics approach was utilized for Phytophthora analysis. The collection of 37 Phytophthora isolates representing 12 different species was screened, and species-specific peptide patterns were identified. Next, Phytophthora proteins were detected in planta, employing model plants S. tuberosum and H. vulgare. Although the evolutionarily conserved sequences represented more than 10% of the host proteome and limited the pathogen detection, the comparison between qPCR and protein data highlighted more than 300 protein markers correlated positively with the amount of P. infestans DNA. Finally, the analysis of P. palmivora response in barley proteome and metabolome revealed significant alterations in primary metabolism, providing the first insight into molecular mechanisms behind this biotic interaction.