title: Expression of potato S-adenosyl-L-methionine synthase (SbSAMS) gene altered developmental characteristics and stress responses in transgenic Arabidopsis plants.
abstract: S-adenosyl-L-methionine (SAM) synthase (SAMS) catalyze the biosynthesis of SAM, which is a precursor for ethylene and polyamines, and a methyl donor for a number of biomolecules. A full-length cDNA of SAMS from Solanum brevidens was expressed in Arabidopsis thaliana to study its physiological function. RT-PCR analysis showed that SbSAMS expression was enhanced significantly in S. brevidens leaves upon treatment with salt, mannitol, ethephon, IAA and ABA. The transgenic SbSAMS overexpression lines accumulated higher levels S-adenosyl homocysteine (SAHC) and ethylene concomitantly with increased SAM level. Expression levels of genes related to ethylene biosynthesis such as ACC synthase, but not polyamine biosynthesis genes were enhanced in SbSAMS overexpressing Arabidopsis lines. In addition, ABA responsive, wound and pathogen-inducible genes were upregulated in SbSAMS transgenic Arabidopsis plants. Transgenic Arabidopsis lines exhibited higher salt and drought stress tolerance compared to those of vector control. Based on these results we conclude that SbSAMS is expressed under abiotic stress to produce SAM as a broad-spectrum signal molecule to upregulate stress-related genes including ethylene and ABA biosynthetic pathway genes responsible for ABA, pathogen and wound responses.
authors.affiliation: Department of Bioscience and Bioinformatics, Graduate School, Myongji University, Yongin, Gyeonggi-Do 449-728, Republic of Korea.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Bioinformatics, Graduate School, Myongji University, Yongin, Gyeonggi-Do 449-728, Republic of Korea.
authors.forename: Sang Hyon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Center for Nutraceutical and Pharmaceutical Materials, Myongji University, Cheoin-gu, Yongin, Gyeonggi-Do 449-728, Republic of Korea.
authors.forename: Sasikumar Arunachalam
authors.initials: SA
authors.lastname: Palaniyandi
authors.affiliation: Center for Nutraceutical and Pharmaceutical Materials, Myongji University, Cheoin-gu, Yongin, Gyeonggi-Do 449-728, Republic of Korea. Electronic address: ymichigan@mju.ac.kr.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Yang
authors.affiliation: Department of Bioscience and Bioinformatics, Graduate School, Myongji University, Yongin, Gyeonggi-Do 449-728, Republic of Korea; Center for Nutraceutical and Pharmaceutical Materials, Myongji University, Cheoin-gu, Yongin, Gyeonggi-Do 449-728, Republic of Korea. Electronic address: jwsuh@mju.ac.kr.
authors.forename: Joo-Won
authors.initials: JW
authors.lastname: Suh
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D008716:Methionine Adenosyltransferase / Q000096:biosynthesis* / Q000235:genetics; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development*; D032322:Solanum / Q000201:enzymology / Q000235:genetics*; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D008716:Methionine Adenosyltransferase
keywords: Abiotic stress; Ethylene; S-Adenosyl-l-methionine; SAM synthase