Anabaena sp. PCC7120 transformed with glycine methylation genes from Aphanothece halophytica synthesized glycine betaine showing increased tolerance to salt
Anabaena sp. PCC7120 transformed with glycine methylation genes from Aphanothece halophytica synthesized glycine betaine showing increased tolerance to salt
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DOI：
10.1007/s00203-012-0824-z
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发表时间：
2012-06
影响因子：
2.8
通讯作者：
R. Waditee‐Sirisattha;Meenakshi Singh;H. Kageyama;Daungjai Sittipol;A. Rai;T. Takabe
中科院分区：
文献类型：
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作者：
R. Waditee‐Sirisattha;Meenakshi Singh;H. Kageyama;Daungjai Sittipol;A. Rai;T. Takabe
光合固氮水藻虽然对盐敏感，但在热带水田的碳氮循环中起着重要的作用。通过表达甘氨酸甜菜碱合成基因来提高anabaenacells的耐盐性是一个有趣的研究课题。由于蓝藻中缺乏胆碱，胆碱氧化酶不能用于合成甘氨酸甜菜碱。在这里，从耐盐蓝藻中编码甘氨酸-肌氨酸和二甲基甘氨酸甲基转移酶（ApGSMT-DMT）的基因在anabaenasp中表达。应变PCC7120。表达apgsmt - dmt的anabaenact细胞无需添加任何物质即可合成甘氨酸甜菜碱。甜菜碱的积累水平随着盐浓度的升高而增加。与对照细胞相比，转化细胞表现出更好的生长和更强的耐盐性。目前的工作提供了一个前景，工程固氮蓝藻通过操纵从头合成甘氨酸甜菜碱增强耐受性。
Photosynthetic, nitrogen-fixingAnabaenastrains play an important role in the carbon and nitrogen cycles in tropical paddy fields although they are salt sensitive. Improvement in salt tolerance ofAnabaenacells by expressing glycine betaine–synthesizing genes is an interesting subject. Due to the absence of choline in cyanobacteria, choline-oxidizing enzyme could not be used for the synthesis of glycine betaine. Here, the genes encoding glycine-sarcosine and dimethylglycine methyltransferases (ApGSMT-DMT) from a halotolerant cyanobacteriumAphanothece halophyticawere expressed inAnabaenasp. strain PCC7120. TheApGSMT-DMT-expressingAnabaenacells were capable of synthesizing glycine betaine without the addition of any substance. The accumulation level of glycine betaine inAnabaenaincreased with rise of salt concentration. The transformed cells exhibited an improved growth and more tolerance to salinity than the control cells. The present work provides a prospect to engineer a nitrogen-fixing cyanobacterium having enhanced tolerance to stress by manipulating de novo synthesis of glycine betaine.