title: The role of a cytosolic superoxide dismutase in barley-pathogen interactions.
abstract: Reactive oxygen species (ROS), including superoxide ( O2·-/ HO2·) and hydrogen peroxide (H2O2), are differentially produced during resistance responses to biotrophic pathogens and during susceptible responses to necrotrophic and hemi-biotrophic pathogens. Superoxide dismutase (SOD) is responsible for the catalysis of the dismutation of O2·-/ HO2· to H2O2, regulating the redox status of plant cells. Increased SOD activity has been correlated previously with resistance in barley to the hemi-biotrophic pathogen Pyrenophora teres f. teres (Ptt, the causal agent of the net form of net blotch disease), but the role of individual isoforms of SOD has not been studied. A cytosolic CuZnSOD, HvCSD1, was isolated from barley and characterized as being expressed in tissue from different developmental stages. HvCSD1 was up-regulated during the interaction with Ptt and to a greater extent during the resistance response. Net blotch disease symptoms and fungal growth were not as pronounced in transgenic HvCSD1 knockdown lines in a susceptible background (cv. Golden Promise), when compared with wild-type plants, suggesting that cytosolic O2·-/ HO2· contributes to the signalling required to induce a defence response to Ptt. There was no effect of HvCSD1 knockdown on infection by the hemi-biotrophic rice blast pathogen Magnaporthe oryzae or the biotrophic powdery mildew pathogen Blumeria graminis f. sp. hordei, but HvCSD1 also played a role in the regulation of lesion development by methyl viologen. Together, these results suggest that HvCSD1 could be important in the maintenance of the cytosolic redox status and in the differential regulation of responses to pathogens with different lifestyles.
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, SA, 5064, Australia.
authors.forename: Damien J
authors.initials: DJ
authors.lastname: Lightfoot
authors.affiliation: Department of Crop Genetics, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Graham R D
authors.initials: GR
authors.lastname: Mcgrann
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, SA, 5064, Australia.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Able
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000502:physiology*; D001483:Base Sequence; D016923:Cell Death; D003600:Cytosol / Q000201:enzymology*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D020082:Magnaporthe / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014026:Nicotiana / Q000382:microbiology
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase
keywords: hemi-biotroph; net blotch disease; plant-pathogen interaction; reactive oxygen species; superoxide dismutase