A genome survey of Moniliophthora perniciosa gives new insights into Witches Broom Disease of cacao.
Mondego, J. M. C.; carazzolle, M. F.; Costa, G. G. L.; Formighieri, E. F.; Parizzi, L. P.;
RIncones, J.; Cotomacci, C.; Carraro, D. M.; Cunha, A. F.; Carrer, H.; Vidal, R. O.; Estrela, R. E.; García, O.; Thomazella, D. P. T.; Oliveira, B. V. O.; Pires, A. B. l.; Rio, M. C. S.; Araújo, M. R. R.; Castro, L. A. B.; Gramacho, K. P.; Gonçalves, M. S.; Góes-Neto, A.; Barbosa, L. V.; Guiltinan, M.; Bailey, B. A.; Meinhardt, L. W.; Cascardo, J. C.M.; Perreira, G. A. G. BMC Genomics. 9:548. Doi:10.1186/1471-2164-9-548 0
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 cacaos 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.