title: Functional analysis of oxidative burst in sugarcane smut-resistant and -susceptible genotypes.
abstract: Smut pathogen induced an early modulation of the production and scavenging of reactive oxygen species during defence responses in resistant sugarcane that coincided with the developmental stages of fungal growth. Sporisorium scitamineum is the causal agent of sugarcane smut disease. In this study, we characterized sugarcane reactive oxygen species (ROS) metabolism in response to the pathogen in smut-resistant and -susceptible genotypes. Sporisorium scitamineum teliospore germination and appressorium formation coincided with H2O2accumulation in resistant plants. The superoxide dismutase (SOD) activity was not responsive in any of the genotypes; however, a higher number of isoenzymes were detected in resistant plants. In addition, related to resistance were lipid peroxidation, a decrease in catalase (CAT), and an increase in glutathione S-transferase (GST) activities and an earlier transcript accumulation of ROS marker genes (CAT3, CATA, CATB, GST31, GSTt3, and peroxidase 5-like). Furthermore, based on proteomic data, we suggested that the source of the increased hydrogen peroxide (H2O2) may be due to a protein of the class III peroxidase, which was inhibited in the susceptible genotype. H2O2is sensed and probably transduced through overlapping systems related to ascorbate-glutathione and thioredoxin to influence signalling pathways, as revealed by the presence of thioredoxin h-type, ascorbate peroxidase, and guanine nucleotide-binding proteins in the infected resistant plants. Altogether, our data depicted the balance of the oxidative burst and antioxidant enzyme activity in the outcome of this interaction.
authors.affiliation: Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP, 13400-970, Brazil.
authors.forename: Leila P
authors.initials: LP
authors.lastname: Peters
authors.affiliation: Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP, 13400-970, Brazil.|Current address: Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Ilha Solteira, SP, 15385-000, Brazil.
authors.forename: Giselle
authors.initials: G
authors.lastname: Carvalho
authors.affiliation: Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP, 13400-970, Brazil.
authors.forename: Milca B
authors.initials: MB
authors.lastname: Vilhena
authors.affiliation: Centro Avançado de Pesquisa Tecnológica do Agronegócio de Cana-IAC/APTA, Rod. Antonio Duarte Nogueira, Km 321, Ribeirão Preto, SP, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Creste
authors.affiliation: Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP, 13400-970, Brazil.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Azevedo
authors.affiliation: Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP, 13400-970, Brazil. cbmontei@usp.br.
authors.forename: Claudia B
authors.identifier: http://orcid.org/0000-0002-1238-9354
authors.initials: CB
authors.lastname: Monteiro-Vitorello
mesh_terms: D004198:Disease Susceptibility / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005838:Genotype; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D010935:Plant Diseases / Q000382:microbiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst / Q000502:physiology*; D031786:Saccharum / Q000382:microbiology / Q000502:physiology*; D014588:Ustilago / Q000472:pathogenicity*
chemical_list: D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide
keywords: Antioxidant enzymes; Biotic stress; Hydrogen peroxide; Phytopathogen; Reactive oxygen species; Sporisorium scitamineum