title: The SUI-homologous translation initiation factor eIF-1 is involved in regulation of ion homeostasis in rice.
abstract: Halophytes survive high salinity by using complex adaptive mechanisms. In a search for novel molecular mechanisms involved in salt acclimation, transcript analyses revealed increased expression of a SUI-homologous translation initiation factor eIF-1 in the salt-tolerant grass species Festuca rubra ssp. littoralis but not in rice. Upon analysis of the cell specificity of eIF-1 transcription by in situ polymerase chain reaction (PCR), predominant signals were detected in rice leaf mesophyll. To further examine the role of eIF-1 in salt tolerance, transgenic rice plants were generated that over-express this factor under the control of the CaMV-35S promoter. The eIF-1 over-expressing lines showed improved growth under salt stress that was correlated with maintenance of photosynthetic activity and reduced Na(+) and Cl(-) accumulation in leaves. The transgenic rice lines also activated expression of the vacuolar H(+)-ATPase. In addition, an oxidoreductase that belongs to the aldo/keto reductase family was identified as a gene with modified expression in the eIF-1 over-expressing lines, compared with wild-type rice. Our data suggest that eIF-1 has a central function in salt-stress adaptation in rice by regulating ion accumulation and the intracellular redox status.
authors.affiliation: Department of Physiology and Biochemistry of Plants, Faculty of Biology, University of Bielefeld, Bielefeld, Germany.
authors.forename: C J
authors.initials: CJ
authors.lastname: Diédhiou
authors.forename: O V
authors.initials: OV
authors.lastname: Popova
authors.forename: K-J
authors.initials: KJ
authors.lastname: Dietz
authors.forename: D
authors.initials: D
authors.lastname: Golldack
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000975:Antioxidants / Q000378:metabolism; D015977:Eukaryotic Initiation Factor-1 / Q000378:metabolism*; D031751:Festuca / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006706:Homeostasis / Q000502:physiology; D007477:Ions / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010448:Peptide Initiation Factors; D030821:Plants, Genetically Modified / Q000378:metabolism; D050436:Regulatory Elements, Transcriptional; D029701:Saccharomyces cerevisiae Proteins; D054712:Salinity; D012964:Sodium / Q000378:metabolism; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015977:Eukaryotic Initiation Factor-1; D007477:Ions; D010448:Peptide Initiation Factors; C072076:SUI1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012964:Sodium; D010088:Oxidoreductases; D025262:Vacuolar Proton-Translocating ATPases