The hemibiotrophic cacao pathogen Moniliophthora perniciosa depends on a mitochondrial alternative oxidase for biotrophic development

Abstract

The tropical pathogen Moniliophthora perniciosa causes witches’ broom disease in cacao. As a hemibiotrophic fungus, it initially colonizes the living host tissues (biotrophic phase), and later grows over the dead plant (necrotrophic phase). Little is known about the mechanisms that promote these distinct fungal phases or mediate the transition between them.An alternative oxidase gene (Mp-aox) was identified in the M. perniciosa genome and its expression was analyzed througout the fungal life cycle. In addition, the effects of inhibitors of the cytochrome-dependent respiratory chain (CRC) and alternative oxidase (AOX) were evaluated on the in vitro development of M. perniciosa.Larger numbers of Mp-aox transcripts were observed in the biotrophic hyphae, which accordingly showed elevated sensitivity to AOX inhibitors. More importantly, the inhibition of CRC prevented the transition from the biotrophic to the necrotrophic phase, and the combined use of a CRC and AOX inhibitor completely halted fungal growth.On the basis of these results, a novel mechanism is presented in which AOX plays a role in the biotrophic development of M. perniciosa and regulates the transition to its necrotrophic stage. Strikingly, this model correlates well with the infection strategy of animal pathogens, particularly Trypanosoma brucei, which uses AOX as a strategy for pathogenicity.

Genetic and Functional Investigation of Zn2Cys6Transcription Factors RSE2 and RSE3 in Podospora anserina

“…Several studies indicate that the AOX is upregulated in oxidative stress conditions (14,15). It is developmentally regulated in the pathogenic dimorphic fungus Paracoccidioides brasiliensis (15) and plays an important role in the life cycle of the fungal plant pathogen Moniliophthora perniciosa (16). Recently, it has been shown that the AOX is relevant to the virulence of several human-pathogenic fungi, such as Cryptococcus neoformans (17), Aspergillus fumigatus (18), and Paracoccidioides brasiliensis (19).…”

Overexpression of a Novel Biotrophy-Specific Colletotrichum truncatum Effector, CtNUDIX, in Hemibiotrophic Fungal Phytopathogens Causes Incompatibility with Their Host Plants

“…Thereafter, they rarely formed necrotrophic secondary hyphae, and their growth was restricted to primary hyphae occupying single epidermal cells, which remained alive even after prolonged incubation. More recently, a mitochondrial alternative oxidase from Moniliophthora perniciosa, the causal agent of witches' broom disease in cacao, was identified as a regulator of the BNS (7). However, none of these proteins were secreted into the host.…”

Estudos de Modelagem Comparativa da lanosterol 14-alfa demetilase de Moniliophthora perniciosa

“…In consequence of the spread of witches' broom, Brazil, which ranked second in world exports, began importing the fruit. The reflection on the local economy was immediate, because the eradication of producing areas led to unemployment of many rural workers (THOMAZELLA et al, 2012;ZAPAROLI et al, 2009). …”

“…The basidiomycete Moniliophthora perniciosa (AIME; PHILLIPS-MORA, 2005) is a hemibiotrophic fungus that causes the witches' broom disease, which has become of the spreading phytopathological problem of the producing regions of Theobroma cacao in the American continent (THOMAZELLA et al, 2012;ZAPAROLI et al, 2009). In Brazil, this pathogen was identified in 1989 in the south of Bahia State, a region of cocoa intensive plantation, causing an impact on the local economy.…”

“…However, the forms of control so far have low efficiency (THOMAZELLA et al, 2012;ZAPAROLI et al, 2009). Currently, several efforts have been made in the elucidation of molecular targets (JUNIOR et al, 2013;PINHEIRO et al, 2012;SANTOS et al, 2011;SENA et al, 2011).…”