title: Molecular cloning and characterization of a novel soybean gene encoding a leucine-zipper-like protein induced to salt stress.
abstract: To understand molecular responses to salt stress in soybean (Glycine max [L.] Merr.), we identified 106 salt-inducible soybean genes that expressed differentially at 72 h after 100 mM NaCl treatment using the cDNA-amplified fragment length polymorphism (AFLP) method. The genes were designated as G. max Transcript-Derived Fragments (GmTDFs). Among these genes, we characterized a soybean gene GmTDF-5 that encoded an unknown protein of 367 amino acids. The GmTDF-5 protein was a putative cytosolic protein with two leucine-zipper motifs at the N-terminal and was calculated as 40.7 kDa. Southern blot analysis indicated that GmTDF-5 presents as an intron-less single gene on soybean genome and possibly distributes narrowly throughout the higher plants. By 100 mM NaCl treatment, the gene expression of GmTDF-5 was induced in the stem and lower-expanded leaf, and the amount of mRNA increased 5.1- and 2.0-fold up to 72 h, respectively. Interestingly, GmTDF-5 expression in the upper-leaf appeared dramatically with 10.0-fold increase at 72 h after the salt stress, but not until 48 h. Hyperosmotic pressure (mannitol treatment) and dehydration also caused the increases similar to NaCl treatment in the levels of GmTDF-5 expression. These results suggest that GmTDF-5 might be a novel cytosolic leucine-zipper-like protein functioning in mature organs of soybean shoot against water-potential changes.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Department of Applied Biological Resource Sciences, School of Agriculture, Ibaraki University, Chuo-3-21-1, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Aoki
authors.forename: Akemi
authors.initials: A
authors.lastname: Kanegami
authors.forename: Michiko
authors.initials: M
authors.lastname: Mihara
authors.forename: Toshio
authors.initials: T
authors.lastname: Kojima
authors.forename: Masakazu
authors.initials: M
authors.lastname: Shiraiwa
authors.forename: Hidenari
authors.initials: H
authors.lastname: Takahara
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D003681:Dehydration; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D008353:Mannitol / Q000494:pharmacology; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics; D018547:Plant Stems / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology*; D030262:Soybean Proteins / Q000737:chemistry / Q000235:genetics*; D013025:Glycine max / Q000187:drug effects* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D030262:Soybean Proteins; D008353:Mannitol; D012965:Sodium Chloride; D000040:Abscisic Acid; D020156:Salicylic Acid