Searching for Moniliophthora perniciosa pathogenicity genes

Autor(es)

Leal, Gildemberg A. ^[1] ; Gomes, Luiz H. ^[2] ; Albuquerque, Paulo S. B. ^[3] ; Tavares, Flavio C. A. ^[2] ; Figueira, Antonio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, BR-13418900 Piracicaba, SP - Brazil

^[3] Comissao Execut Plano Lavoura Cacaueira, ERJOH, BR-67105970 Marituba, PA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FUNGAL BIOLOGY; v. 114, n. 10, p. 842-854, OCT 2010.
• Citações Web of Science: 15

Resumo

The basidiomycete Moniliophthora perniciosa is the causal agent of witches' broom disease of Theobroma cacao (cacao). Pathogenesis mechanisms of this hemibiotrophic fungus are largely unknown. An approach to identify putative pathogenicity genes is searching for sequences induced in mycelia grown under in vitro conditions. Using this approach, genes from M. perniciosa induced under limiting nitrogen and light were identified from a cDNA library enriched by suppression subtractive hybridization as potential putative pathogenicity genes. From the 159 identified unique sequences, 59 were annotated and classified by gene ontology. Two sequences were categorized as ``Defence genes, Virulence, and Cell response{''} presumably coding for allergenic proteins, whose homologues from other fungi are inducers of animal or plant defences. Differential gene expression was evaluated by quantitative amplification of reversed transcripts (RT-qPCR) of the putative identified genes coding for the two allergenic proteins (Aspf13 and 88KD), and for the enzymes Arylsulfatase (AS); Aryl-Alcohol Oxidase; Aldo-Keto Reductase (AK); Cytochrome P450 (P450); Phenylalanine Ammonia-Lyase; and Peroxidase from mycelia grown under contrasting N concentrations. All genes were validated for differential expression, except for the putative Peroxidase. The same eight genes were analysed for expression in susceptible plants inoculated with M. perniciosa, and six were induced during the early asymptomatic stage of the disease. In infected host tissues, transcripts of 88KD and AS were found more abundant at the biotrophic phase, while those from Aspf13, AK, PAL, and P450 accumulated at the necrotrophic phase, enabling to suggest that mycelia transition from biotrophic to necrotrophic might occur earlier than currently considered. These sequences appeared to be virulence life-style genes, which encode factors or enzymes that enable invasion, colonization or intracellular survival, or manipulate host factors to benefit the pathogen's own survival in the hostile environment. (C) 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 07/07175-0 - Análise genética da resposta de defesa de Theobroma cacao a Moniliophthora perniciosa, agente causal da vassoura-de-bruxa
• Beneficiário: Antonio Vargas de Oliveira Figueira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 03/11483-0 - Identificação de regiões genômicas e genes diferencialmente expressos associados à resistência do cacaueiro (Theobroma cacao L.) à vassoura-de-bruxa (agente causal Crinipellis perniciosa)
• Beneficiário: Antonio Vargas de Oliveira Figueira
• Modalidade de apoio: Auxílio à Pesquisa - Regular