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

Author(s):Show less -

Thomazella, Daniela P. T. ^[1] ; Teixeira, Paulo Jose P. L. ^[1] ; Oliveira, Halley C. ^[2] ; Saviani, Elzira E. ^[2] ; Rincones, Johana ^[1] ; Toni, Isabella M. ^[1] ; Reis, Osvaldo ^[1] ; Garcia, Odalys ^[1] ; Meinhardt, Lyndel W. ^[3] ; Salgado, Ione ^[2] ; Pereira, Goncalo A. G. ^[1]

Affiliation

^[1] Univ Estadual Campinas UNICAMP, Inst Biol, Lab Genom & Expressao, Dept Genet Evolucao & Bioagentes, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas UNICAMP, Inst Biol, Dept Biol Vegetal, BR-13083970 Campinas, SP - Brazil

^[3] USDA ARS, Sustainable Perennial Crops Lab, Beltsville, MD 20705 - USA

• Document type: Journal article
• Source: NEW PHYTOLOGIST; v. 194, n. 4, p. 1025-1034, JUN 2012.
• Web of Science Citations: 28

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 similar to 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 similar to 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 similar to 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. (AU)

• FAPESP's process: 09/50119-9 - Integrated and comparative study of three fungal diseases of cacao: witches' broom, frosty pod rot and brown-rot, aiming at understanding the pathogenic mechanisms for the development of control strategies
• Grantee: Gonçalo Amarante Guimarães Pereira
• Support Opportunities: Research Projects - Thematic Grants