Towards Phytopathogen Diagnostics? Coconut Bud Rot Pathogen Phytophthora palmivora Mycelial Proteome Analysis Informs Genome Annotation.

Planetary agriculture stands to benefit immensely from phytopathogen diagnostics, which would enable early detection of pathogens with harmful effects on crops. For example, Phytophthora palmivora is one of the most destructive phytopathogens affecting many economically important tropical crops such as coconut. P. palmivora causes diseases in over 200 host plants, and notably, the bud rot disease in coconut and oil palm, which is often lethal because it is usually detected at advanced stages of infection. Limited availability of large-scale omics datasets for P. palmivora is an important barrier for progress toward phytopathogen diagnostics. We report here the mycelial proteome of P. palmivora using high-resolution mass spectrometry analysis. We identified 8073 proteins in the mycelium. Gene Ontology-based functional classification of detected proteins revealed 4884, 4981, and 3044 proteins, respectively, with roles in biological processes, molecular functions, and cellular components. Proteins such as P-loop, NTPase, and WD40 domains with key roles in signal transduction pathways were identified. KEGG pathway analysis annotated 2467 proteins to various signaling pathways, such as phosphatidylinositol, Ca2+, and mitogen-activated protein kinase, and autophagy and cell cycle. These molecular substrates might possess vital roles in filamentous growth, sporangia formation, degradation of damaged cellular content, and recycling of nutrients in P. palmivora. This large-scale proteomics data and analyses pave the way for new insights on biology, genome annotation, and vegetative growth of the important plant pathogen P. palmivora. They also can help accelerate research on future phytopathogen diagnostics and preventive interventions.

Aß42 Expressing Drosophila melanogaster Model for Alzheimer's Disease: Quantitative Proteomics Identifies Altered Protein Dynamics of Relevance to Neurodegeneration.

Production and deposition of ß-amyloid peptides (Aß) are among the major hallmarks of the pathogenesis of Alzheimer's disease (AD). Mapping the altered protein dynamics associated with Aß accumulation and neuronal damage may open up new avenues to innovation for drug target discovery in AD. Using quantitative proteomics, we report new findings from the amyloid beta-peptide with 42 amino acids (Aß42) expressing Drosophila melanogaster model for AD compared to that of the wild-type flies. We identified 302,241 peptide-spectrum matches with 25,641 nonredundant peptides corresponding to 7959 D. melanogaster proteins. Furthermore, we unraveled 538 significantly altered proteins in Aß42 expressing flies. These differentially expressed proteins were enriched for biological processes associated with neuronal damage leading to AD progression. We also identified 463 unique post-translational modification events mapping to 202 proteins from the same dataset. Among these, 303 modified peptides corresponding to 246 proteins were also altered in the AD model. These modified proteins are known to be involved in the disruption of molecular functions maintaining neuronal plasticity. This study provides new molecular leads on altered protein dynamics relevant to neurodegeneration, neuroplasticity, and AD progression induced by Aß42 toxicity. These proteins may prove useful to discover new drugs in an AD model of D. melanogaster and evaluate their efficacy and mode of molecular action in the future.