IbSIMT1, a novel salt-induced methyltransferase gene from Ipomoea batatas, is involved in salt tolerance
IbSIMT1, a novel salt-induced methyltransferase gene from Ipomoea batatas, is involved in salt tolerance
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IbSIMT1 是一种来自红薯的新型盐诱导甲基转移酶基因，与耐盐性有关
DOI：
10.1007/s11240-014-0638-6
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发表时间：
2015-02-01
影响因子：
3
通讯作者：
Liu, Qingchang
中科院分区：
文献类型：
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作者：
Liu, Degao;He, Shaozhen;Liu, Qingchang
S-腺苷甲硫氨酸（SAM）依赖性甲基转移酶（MTase）基因是一个多基因家族，然而，只有少数已在功能水平上的特点。本研究从耐盐甘薯（Ipomoea batatas（L.）林。）ND 98线。IbSIMT 1含有一个功能未知的DUF 248结构域和一个MTase结构域。盐胁迫和脱落酸处理均使IbSIMT 1基因在甘薯中的表达上调。将IbSIMT 1过表达甘薯（cv.与野生型相比，上树19）植株表现出显著更高的耐盐性。脯氨酸含量显着增加，而丙二醛含量显着降低转基因植株。超氧化物歧化酶（SOD）活性和光合作用在转基因植株中显着提高。还发现H2 O2在转基因植物中的积累显著低于野生型。IbSIMT 1的过表达上调了盐胁迫响应基因，包括吡咯啉-5-羧酸合成酶、吡咯啉-5-羧酸还原酶、SOD、psbA和磷酸核酮糖激酶基因。这些结果表明，新的IbSIMT 1基因参与甘薯耐盐性，并通过调节渗透平衡，保护膜完整性和光合作用，增加活性氧自由基清除能力提高转基因甘薯植物的耐盐性。
S-adenosyl-methionine (SAM)-dependent methyltransferase (MTase) genes are a multigene family; however, only a few have been characterized at the functional level. In the present study, a novel salt-induced SAM-dependent MTase gene, named IbSIMT1, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line ND98. IbSIMT1 contains a DUF248 domain of unknown function and an MTase domain. Expression of IbSIMT1 was up-regulated in sweetpotato under salt stress and abscisic acid treatment. The IbSIMT1-overexpressing sweetpotato (cv. Shangshu 19) plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbSIMT1 up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes under salt stress. These findings suggest that the novel IbSIMT1 gene is involved in sweetpotato salt tolerance and enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity.