title: Enhancement of stress tolerance in transgenic tobacco plants constitutively expressing AtIpk2beta, an inositol polyphosphate 6-/3-kinase from Arabidopsis thaliana.
abstract: Inositol phosphates (IPs) and their turnover products have been implicated to play important roles in stress signaling in eukaryotic cells. In higher plants genes encoding inositol polyphosphate kinases have been identified previously, but their physiological functions have not been fully resolved. Here we expressed Arabidopsis inositol polyphosphate 6-/3-kinase (AtIpk2beta) in two heterologous systems, i.e. the yeast Saccharomyces cerevisiae and in tobacco (Nicotiana tabacum), and tested the effect on abiotic stress tolerance. Expression of AtIpk2beta rescued the salt-, osmotic- and temperature-sensitive growth defects of a yeast mutant strain (arg82Delta) that lacks inositol polyphosphate multikinase activity encoded by the ARG82/IPK2 gene. Transgenic tobacco plants constitutively expressing AtIpk2beta under the control of the Cauliflower Mosaic Virus 35S promoter were generated and found to exhibit improved tolerance to diverse abiotic stresses when compared to wild type plants. Expression patterns of various stress responsive genes were enhanced, and the activities of anti-oxidative enzymes were elevated in transgenic plants, suggesting a possible involvement of AtIpk2beta in plant stress responses.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Renjie
authors.initials: R
authors.lastname: Tang
authors.forename: Jinqi
authors.initials: J
authors.lastname: Zhu
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Bernd
authors.initials: B
authors.lastname: Mueller-Roeber
authors.forename: Huijun
authors.initials: H
authors.lastname: Xia
authors.forename: Hongxia
authors.initials: H
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics*; D017931:DNA Primers; D004361:Drug Tolerance; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018384:Oxidative Stress; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology; D016133:Polymerase Chain Reaction; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D006861:Hydrogen Peroxide; C523083:IPK2beta protein, Arabidopsis; D017853:Phosphotransferases (Alcohol Group Acceptor)