title: Expression analysis of proline metabolism-related genes from halophyte Arabis stelleri under osmotic stress conditions.
abstract: Arabis stelleri var. japonica evidenced stronger osmotic stress tolerance than Arabidopsis thaliana. Using an A. thaliana microarray chip, we determined changes in the expression of approximately 2 800 genes between A. stelleri plants treated with 0.2 M mannitol versus mock-treated plants. The most significant changes in the gene expression patterns were in genes defining cellular components or in genes associated with the endomembrane system, stimulus response, stress response, chemical stimulus response, and defense response. The expression patterns of three de novo proline biosynthesis enzymes were evaluated in A. stelleri var. japonica seedlings treated with 0.2 M mannitol, 0.2 M sorbitol, and 0.2 M NaCl. The expression of Δ¹ -pyrroline-5-carboxylate synthetase was not affected by NaCl stress but was similarly induced by mannitol and sorbitol. The proline dehydrogenase gene, which is known to be repressed by dehydration stress and induced by free L-proline, was induced at an early stage by mannitol treatment, but the level of proline dehydrogenase was increased later by treatment with both mannitol and NaCl. The level of free L-proline accumulation increased progressively in response to treatments with mannitol, sorbitol, and NaCl. Mannitol induced L-proline accumulation more rapidly than NaCl or sorbitol. These findings demonstrate that the osmotic tolerance of the novel halophyte, Arabis stelleri, is associated with the accumulation of L-proline.
authors.affiliation: Department of Genetic Engineering, Sungkyunkwan University, Suwon, South Korea.
authors.forename: Yuchul
authors.initials: Y
authors.lastname: Jung
authors.forename: Jungan
authors.initials: J
authors.lastname: Park
authors.forename: Yunjung
authors.initials: Y
authors.lastname: Choi
authors.forename: Jin-Gweon
authors.initials: JG
authors.lastname: Yang
authors.forename: Donggiun
authors.initials: D
authors.lastname: Kim
authors.forename: Beom-Gi
authors.initials: BG
authors.lastname: Kim
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Roh
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Lee
authors.forename: Chung-Kyoon
authors.initials: CK
authors.lastname: Auh
authors.forename: Sukchan
authors.initials: S
authors.lastname: Lee
mesh_terms: D031214:Arabis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D009997:Osmotic Pressure / Q000502:physiology*; D011392:Proline / Q000378:metabolism*; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D012965:Sodium Chloride; D011392:Proline