Padrões de evolução genica e genomica em Moniliophthora perniciosa (Basiomicota, Agaricales), agente causal da vassoura de bruxa / Paterns of genomic evolution in Moniliophthora perniciosa (Basiomicota, Agaricales) causal agent of witche s broom disease

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

Moniliophthora perniciosa (Stahel) Aime &Phillips-Mora is a hemibiotrophic basidiomycete fungus that causes witches broom disease in cocoa (Theobroma cacao L.). This disease is characterized by the production of hyperplasic and hypertrophic stems and parthenogenetic fruits during biotrophic life-phasee, followed by necrosis of infected tissues during necrotrophic life-phase. This is the main disease affecting the cocoa production in South America and the Caribbean, causing a decrease of more than 65% in the production in southern Bahia, the main producing region. Several genes related to pathogenicity were found in M. perniciosa as part of the Witches Broom Genome Project. However the patterns of evolution of these genes, that could help to understand the evolution of plant pathogenicity in this species, were not yet studied. Also the changes occurred in this species at a genomic level during its evolution were not studied. These changes are particularly relevant since the majority of species closely related to M. perniciosa is not phytopathogenic and so the understanding of this evolution would help to understand the evolution of plant pathogens in general. This work attempts to increase the knowledge about the emergence of pathogenicity in M. perniciosa studding the evolution of genes potentially related to it, therefore increasing the knowledge about the witches broom and helping in the search for a way to control the disease. To do that, it were studied the evolutionary patterns of several genes related with the necrosis process characteristic of witches broom and genes candidate to have been obtained by horizontal gene transfer (HGT). These later were detected by a genome level screening. The results indicate that the evolution of plant pathogenicity in M. perniciosa involved both the acquisition of new genes and the use of genes already present in the saprotrophic ancestral in new functions. In particular, the search for horizontally transferred genes found two genes potentially involved in the disease which were not yet studied, suggesting that the evolutionary analysis at the genomic level is a relevant tool to the choice of genes candidate to laboratory analysis.

ASSUNTO(S)

vassoura-de-bruxa (fitopatologia) cacau genetics transferência horizontal de genes (hgt) cacao moniliophthora perniciosa moniliophthora perniciosa witches broom disease horizontal transference of genes genetica - evolução

Documentos Relacionados