Location: Sustainable Perennial Crops LaboratoryTitle: Global analyses of Ceratocystis cacaofunesta mitochondria: from genome to proteome Author
Submitted to: Biomed Central (BMC) Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2013
Publication Date: 2/11/2013
Citation: Pereira, G.A., Ambrosio, A.B., Nascimento, L.C., Oliveira, B.V., Teixeira, P.J., Tiburcio, R.A., Thomazella, D.P., Leme, A.F., Carazzolle, M.F., Vidal, R.O., Mieczkowski, P., Meinhardt, L.W., Garcia, O. 2013. Global analyses of Ceratocystis cacaofunesta mitochondria: from genome to proteome. Biomed Central (BMC) Genomics. 2013(14):91. Interpretive Summary: Research into diseases of cacao is important to the USA economy because cacao is the raw material for the production of chocolate and the chocolate industry is one of the main consumers of US grown dairy, nuts, oils and sugar products. Ceratocystis cacaofunesta is the causal agent of wilt disease in cacao, which results in the death of the infected trees. Since tree replacement takes 5 to 7 years this disease results in significant economic losses in the affected regions. To understand the how this fungus causes disease we analyzed mitochondrial genome and mitochondrial proteome of this fungus. The results provide the first partial genomic analysis of a species of the Ceratocystis complex and the first predicted mitochondrial protein inventory of a phytopathogenic fungus. This information provides insight into how this fungus functions and provides researchers mechanisms to develop new control measures. Plant pathologists, biologists and mycologists will benefit directly from this information.
Technical Abstract: Background The ascomycete fungus Ceratocystis cacaofunesta is the causal agent of wilt disease in cacao, which results in significant economic losses in the affected producing areas. Despite the economic importance of the Ceratocystis complex of species, no genomic data are available for any of its members. Given that mitochondria play important roles in fungal virulence and the susceptibility/resistance of fungi to fungicides, we performed the first functional analysis of this organelle in Ceratocystis using integrated “omics” approaches. Results The C. cacaofunesta mitochondrial genome (mtDNA) consists of a single, 103,147-bp circular molecule, making this the second largest mtDNA among the Sordariomycetes. Bioinformatics analysis revealed the presence of 15 conserved genes and 37 intronic open read frames in C. cacaofunesta mtDNA. Here, we predicted the mitochondrial proteome (mtProt) of C. cacaofunesta, which is comprised of 1,124 polypeptides - 52 proteins that are mitochondrially encoded and 1,072 that are nuclearly encoded. Transcriptome analysis revealed 33 probable novel genes. Comparisons among the Gene Ontology results of the predicted mtProt of C. cacaofunesta, Neurospora crassa and Saccharomyces cerevisiae revealed no significant differences. Moreover, C. cacaofunesta mitochondria were isolated, and the mtProt was subjected to mass spectrometric analysis. The experimental proteome validated 27% of the predicted mtProt. Our results confirmed the existence of 110 hypothetical proteins and 7 novel proteins of which 83 and 1, respectively, had putative mitochondrial localization. Conclusions The present study provides the first partial genomic analysis of a species of the Ceratocystis complex and the first predicted mitochondrial protein inventory of a phytopathogenic fungus. In addition to the known mitochondrial role in pathogenicity, our results demonstrated that the global function analysis of this organelle is similar in pathogenic and non-pathogenic fungi, suggesting that its relevance in the lifestyle of these organisms should be based on a small number of specific proteins and/or with respect to differential gene regulation. In this regard, particular interest should be directed towards mitochondrial proteins with unknown function and the novel protein that might be specific to this species. Further functional characterization of these proteins could enhance our understanding of the role of mitochondria in phytopathogenicity.