title: Absence of Cu-Zn superoxide dismutase BCSOD1 reduces Botrytis cinerea virulence in Arabidopsis and tomato plants, revealing interplay among reactive oxygen species, callose and signalling pathways.
abstract: Plants activate responses against pathogens, including the oxidative burst. Necrotrophic pathogens can produce reactive oxygen species (ROS) that benefit the colonization process. Previously, we have demonstrated that tomato plants challenged with Botrytis cinerea accumulate ROS and callose, together with the induction of genes involved in defence, signalling and oxidative metabolism. Here, we studied the infection phenotype of the Δbcsod1 strain in both tomato and Arabidopsis plants. This mutant lacks bcsod1, which encodes Cu-Zn superoxide dismutase (SOD). This enzyme catalyses the conversion of superoxide ion ( O2-) into hydrogen peroxide (H2O2). ROS play a protective role and act as signals in plants. Δbcsod1 displayed reduced virulence compared with wild-type B05.10 in both species. Plants infected with Δbcsod1 accumulated less H2O2and more O2- than those infected with B05.10, which is associated with an increase in the defensive polymer callose. This supports a major role of fungal SOD in H2O2production during the plant-pathogen interaction. The early induction of the callose synthase gene PMR4 suggested that changes in ROS altered plant defensive responses at the transcriptional level. The metabolites and genes involved in signalling and in response to oxidative stress were differentially expressed on Δbcsod1 infection, supporting the notion that plants perceive changes in ROS balance and activate defence responses. A higher O2-/H2O2ratio seems to be beneficial for plant protection against this necrotroph. Our results highlight the relevance of callose and the oxylipin 12-oxo-phytodienoic acid (OPDA) in the response to changes in the oxidative environment, and clarify the mechanisms that underlie the responses to Botrytis in Arabidopsis and tomato plants.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, 46980 Paterna, Valencia, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: López-Cruz
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, 46980 Paterna, Valencia, Spain.
authors.forename: Crespo-Salvador
authors.initials: CS
authors.lastname: Óscar
authors.affiliation: Grupo de Bioquímica y Biotecnología, Área de Fisiología Vegetal, Departamento de Ciencias Agrarias y del Medio Natural, Escola Superior de Tecnologia i Ciències Experimentals, Universitat Jaume I, 12071 Castellón, Spain.
authors.forename: Fernández-Crespo
authors.initials: FC
authors.lastname: Emma
authors.affiliation: Grupo de Bioquímica y Biotecnología, Área de Fisiología Vegetal, Departamento de Ciencias Agrarias y del Medio Natural, Escola Superior de Tecnologia i Ciències Experimentals, Universitat Jaume I, 12071 Castellón, Spain.
authors.forename: García-Agustín
authors.initials: GA
authors.lastname: Pilar
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, 46980 Paterna, Valencia, Spain.
authors.forename: González-Bosch
authors.initials: GB
authors.lastname: Carmen
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology*; D020171:Botrytis / Q000201:enzymology* / Q000472:pathogenicity*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005936:Glucans / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics / Q000382:microbiology*; D055442:Metabolome; D009154:Mutation / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D000072105:Superoxide Dismutase-1 / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D014774:Virulence
chemical_list: D000975:Antioxidants; D005936:Glucans; D017382:Reactive Oxygen Species; D013481:Superoxides; C048306:callose; D006861:Hydrogen Peroxide; D000072105:Superoxide Dismutase-1
keywords: Arabidopsis thaliana; Botrytis cinerea; OPDA; ROS; SOD; Solanum lycopersicum; callose