title: Differential expression of jasmonate biosynthesis genes in cacao genotypes contrasting for resistance against Moniliophthora perniciosa.
abstract: The resistance mechanism of cacao against M. perniciosa is likely to be mediated by JA/ET-signaling pathways due to the preferential TcAOS and TcSAM induction in a resistant genotype. The basidiomycete Moniliophthora perniciosa causes a serious disease in cacao (Theobroma cacao L.), and the use of resistant varieties is the only sustainable long-term solution. Cacao resistance against M. perniciosa is characterized by pathogen growth inhibition with reduced colonization and an attenuation of disease symptoms, suggesting a regulation by jasmonate (JA)/ethylene (ET) signaling pathways. The hypothesis that genes involved in JA biosynthesis would be active in the interaction of T. cacao and M. perniciosa was tested here. The cacao JA-related genes were evaluated for their relative quantitative expression in susceptible and resistant genotypes upon the exogenous application of ET, methyl-jasmonate (MJ), and salicylic acid (SA), or after M. perniciosa inoculation. MJ treatment triggered changes in the expression of genes involved in JA biosynthesis, indicating that the mechanism of positive regulation by exogenous MJ application occurs in cacao. However, a higher induction of these genes was observed in the susceptible genotype. Further, a contrast in JA-related transcriptional expression was detected between susceptible and resistant plants under M. perniciosa infection, with the induction of the allene oxide synthase gene (TcAOS), which encodes a key enzyme in the JA biosynthesis pathway in the resistant genotype. Altogether, this work provides additional evidences that the JA-dependent signaling pathway is modulating the defense response against M. perniciosa in a cacao-resistant genotype.
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário, 303, CP 96, Piracicaba, SP, 13400-970, Brazil.|School of Biological Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia.
authors.forename: Celso G
authors.initials: CG
authors.lastname: Litholdo
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário, 303, CP 96, Piracicaba, SP, 13400-970, Brazil.|Universidade Federal de Alagoas, Centro de Ciências Agrárias, BR 104, km 85 N, Rio Largo, AL, 57100-000, Brazil.
authors.forename: Gildemberg A
authors.initials: GA
authors.lastname: Leal
authors.affiliation: Comissão Executiva do Plano da Lavoura Cacaueira, ERJOH, BR 316 km 17, CP 46, Marituba, 67105-970, PA, Brazil.
authors.forename: Paulo S B
authors.initials: PS
authors.lastname: Albuquerque
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário, 303, CP 96, Piracicaba, SP, 13400-970, Brazil. figueira@cena.usp.br.
authors.forename: Antonio
authors.initials: A
authors.lastname: Figueira
mesh_terms: D001487:Basidiomycota / Q000502:physiology*; D002099:Cacao / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000235:genetics
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; C011006:jasmonic acid
keywords: Gene expression; Jasmonic acid; Plant-pathogen interaction; Theobroma cacao; Witches’ broom disease