title: Effect of Medicago sativa Mhb1gene expression on defense response of Arabidopsis thaliana plants.
abstract: Besides the previously described nitric oxide-detoxification activity we identified new features of class-1 non-symbiotic hemoglobin from Medicago sativa (Mhb1). Under in vitro conditions, using peroxidase in-gel activity assay, the Mhb1 protein was shown to possess also peroxidase-like activity. Due to this activity, in the presence of nitrite and hydrogen peroxide, the protein can mediate autonitration and nitration of other proteins at tyrosine residues, as revealed by tandem mass spectrometry and immune assay approaches. Mhb1 through its multifunctional activities can affect different components of signal transduction cascades operating during plant response to infections. This influence is manifested by Mhb1-mediated selective up-regulation of expression of certain pathogen inducible genes in Pseudomonas syringae infected Arabidopsis thaliana plants which overproduce Mhb1, as revealed by reverse transcription-quantitative real-time PCR analysis. Changes in expression level of these genes can influence such processes as synthesis of secondary metabolites, protein degradation and biosynthesis of ethylene. They can also result in alteration of pathogen-induced defense response of Mhb1 transgenic plants.
authors: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, Poland.
authors: Anna
authors: A
authors: Maassen
authors: Jacek
authors: J
authors: Hennig
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006454:Hemoglobins / Q000235:genetics* / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000494:pharmacology; D000455:Medicago sativa / Q000235:genetics*; D009573:Nitrites / Q000378:metabolism; D009585:Nitrogen Dioxide / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics; D044224:Pseudomonas syringae / Q000472:pathogenicity; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D015854:Up-Regulation
chemical_list: D006454:Hemoglobins; C415205:Mhb1 protein, Medicago sativa; D009573:Nitrites; D009687:Nuclear Proteins; D010940:Plant Proteins; D006861:Hydrogen Peroxide; D009585:Nitrogen Dioxide