Research article
A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao
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* Corresponding author: Gonçalo AG Pereira goncalo@unicamp.br
- † Equal contributors
1 Laboratório de Genômica e Expressão, Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, 13083-970, Campinas – SP, Brazil
2 Laboratório de Genômica e Biologia Molecular, Hospital A.C. Camargo, 01509-010, São Paulo – SP, Brazil
3 HEMOCENTRO, Laboratório de Genoma e Hemoglobina, Universidade Estadual de Campinas, 13084-878, Campinas – SP, Brazil
4 Departamento de Ciências Biológicas, ESALQ, USP, 13418-900, Piracicaba – SP, Brazil
5 Laboratório de Genômica e Expressão Gênica, Departamento de Genética e Biologia Molecular, Universidade Estadual de Santa Cruz, 45650-000, Ilhéus – BA, Brazil
6 Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica – PqEB – Av. W5 Norte, 70770-900, Brasília – DF, Brazil
7 CEPLAC/CEPEC/SEFIT, 45600-970, Itabuna – BA, Brazil
8 Laboratório de Biologia Molecular – Faculdade de Farmácia, Universidade Federal da Bahia, 40170-290, Salvador – BA, Brazil
9 Laboratório de Pesquisa em Microbiologia (LAPEM), Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana (UEFS), 44031-460, Feira de Santana – BA, Brazil
10 Laboratório de Biologia Molecular – Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal da Bahia, 40170-290, Salvador – BA, Brazil
11 Department of Horticulture, Pennsylvania State University, University Park, Chester, PA 16802, USA
12 Sustainable Perennial Crops Laboratory, USDA-ARS, 10300 Baltimore Av, Bldg. 001, 18 Beltsville MD 20705-2350, USA
BMC Genomics 2008, 9:548 doi:10.1186/1471-2164-9-548
Published: 18 November 2008Abstract
Background
The basidiomycete fungus Moniliophthora perniciosa is the causal agent of Witches' Broom Disease (WBD) in cacao (Theobroma cacao). It is a hemibiotrophic pathogen that colonizes the apoplast of cacao's meristematic tissues as a biotrophic pathogen, switching to a saprotrophic lifestyle during later stages of infection. M. perniciosa, together with the related species M. roreri, are pathogens of aerial parts of the plant, an uncommon characteristic in the order Agaricales. A genome survey (1.9× coverage) of M. perniciosa was analyzed to evaluate the overall gene content of this phytopathogen.
Results
Genes encoding proteins involved in retrotransposition, reactive oxygen species (ROS) resistance, drug efflux transport and cell wall degradation were identified. The great number of genes encoding cytochrome P450 monooxygenases (1.15% of gene models) indicates that M. perniciosa has a great potential for detoxification, production of toxins and hormones; which may confer a high adaptive ability to the fungus. We have also discovered new genes encoding putative secreted polypeptides rich in cysteine, as well as genes related to methylotrophy and plant hormone biosynthesis (gibberellin and auxin). Analysis of gene families indicated that M. perniciosa have similar amounts of carboxylesterases and repertoires of plant cell wall degrading enzymes as other hemibiotrophic fungi. In addition, an approach for normalization of gene family data using incomplete genome data was developed and applied in M. perniciosa genome survey.
Conclusion
This genome survey gives an overview of the M. perniciosa genome, and reveals that a significant portion is involved in stress adaptation and plant necrosis, two necessary characteristics for a hemibiotrophic fungus to fulfill its infection cycle. Our analysis provides new evidence revealing potential adaptive traits that may play major roles in the mechanisms of pathogenicity in the M. perniciosa/cacao pathosystem.