Truncated Hemoglobins in Actinorhizal Nodules of Datisca glomerata.
2007 (English)In: Plant Biol (Stuttg), ISSN 1435-8603, Vol. 9, no 6, 776-785 p.Article in journal (Other academic) Published
Three types of hemoglobins exist in higher plants, symbiotic, non-symbiotic, and truncated hemoglobins. Symbiotic (class II) hemoglobins play a role in oxygen supply to intracellular nitrogen-fixing symbionts in legume root nodules, and in one case (Parasponia sp.), a non-symbiotic (class I) hemoglobin has been recruited for this function. Here we report the induction of a host gene, Dgtrhb1, encoding a truncated hemoglobin in Frankia-induced nodules of the actinorhizal plant Datisca glomerata Induction takes place specifically in cells infected by the microsymbiont, prior to the onset of bacterial nitrogen fixation. A bacterial gene (Frankia trHbO) encoding a truncated hemoglobin with O (2)-binding kinetics suitable for the facilitation of O (2) diffusion ( ) is also expressed in symbiosis. Nodule oximetry confirms the presence of a molecule that binds oxygen reversibly in D. glomerata nodules, but indicates a low overall hemoglobin concentration suggesting a local function. Frankia TrHbO is likely to be responsible for this activity. The function of the D. glomerata truncated hemoglobin is unknown; a possible role in nitric oxide detoxification is suggested.
Place, publisher, year, edition, pages
2007. Vol. 9, no 6, 776-785 p.
IdentifiersURN: urn:nbn:se:su:diva-19282PubMedID: 17682965OAI: oai:DiVA.org:su-19282DiVA: diva2:185806