Isolation and characterization of S-Adenosylmethionine synthase gene from cucumber and responsive to abiotic stress

• Published in: Plant physiology and biochemistry Vol. 141; pp. 431 - 445
• Main Authors: He, Mei-Wen, Wang, Yu, Wu, Jian-Qiang, Shu, Sheng, Sun, Jin, Guo, Shi-Rong
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.08.2019
• Subjects: Antioxidants - metabolism; Arabidopsis - metabolism; Cucumis sativus; Cucumis sativus - enzymology; Cucumis sativus - physiology; Droughts; Function; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Hydrogen Peroxide - chemistry; Methionine Adenosyltransferase - genetics; Methionine Adenosyltransferase - metabolism; Nicotiana - metabolism; Phylogeny; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified; Polyamines - chemistry; S-adenosylmethionine synthetase; Salt stress; Salt Tolerance; Salts; Stress, Mechanical; Stress, Physiological - genetics; Function; Salt stress; Cucumis sativus; S-adenosylmethionine synthetase; Gene expression
• DOI: 10.1016/j.plaphy.2019.06.006
• ISSN: 0981-9428

S-adenosylmethionine synthetase (SAMS) catalyzes methionine and ATP to generate S-adenosyl-L-methionine (SAM). In plants, accumulating SAMS genes have been characterized and the majority of them are reported to participate in development and stress response. In this study, two putative SAMS genes (CsSAMS1 and CsSAMS2) were identified in cucumber (Cucumis Sativus L.). They displayed 95% similarity and had a high identity with their homologous of Arabidopsis thaliana and Nicotiana tabacum. The qRT-PCR test showed that CsSAMS1 was predominantly expressed in stem, male flower, and young fruit, whereas CsSAMS2 was preferentially accumulated in stem and female flower. And they displayed differential expression profiles under stimuli, including NaCl, ABA, SA, MeJA, drought and low temperature. To elucidate the function of cucumber SAMS, the full-length CDS of CsSAMS1 was cloned, and prokaryotic expression system and transgenic materials were constructed. Expressing CsSAMS1 in Escherichia coli BL21 (DE3) improved the growth of the engineered strain under salt stress. Overexpression of CsSAMS1 significantly increased MDA content, H2O2 content, and POD activity in transgenic lines under non-stress condition. Under salt stress, however, the MDA content of transgenic lines was lower than that of the wild type, the H2O2 content remained high, the polyamine and ACC synthesis in transgenic lines exhibited a CsSAMS1-expressed dependent way. Taken together, our results suggested that both CsSAMS1 and CsSAMS2 were involved in plant development and stress response, and a proper increase of expression level of CsSAMS1 in plants is benificial to improving salt tolerance. •Two cucumber SAMS genes were identified in this study.•CsSAMS1 and CsSAMS2 genes positively responded to abiotic stresses.•CsSAMS1 might be a candidate gene improving plant development and salt tolerance.