Cloning, characterization and functional analysis of two type 1 diacylglycerol acyltransferases (DGAT1s) from Tetraena mongolica.
Cloning, characterization and functional analysis of two type 1 diacylglycerol acyltransferases (DGAT1s) from Tetraena mongolica.
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DOI：
10.1111/jipb.12046
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发表时间：
2013-06
影响因子：
11.4
通讯作者：
Minchun Li;Mingmin Zhao;Hanying Wu;Wang Wu;Yinong Xu
中科院分区：
文献类型：
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作者：
Minchun Li;Mingmin Zhao;Hanying Wu;Wang Wu;Yinong Xu
从四合木（Tetraena mongolica）中克隆了两个编码假定的1型酰基辅酶A：二酰基甘油酰基转移酶（DGAT 1，EC 2.3.1.20）的cDNA，四合木是一种在茎中具有高油含量的极端旱生植物。TmDGAT 1a和TmDGAT 1b的开放阅读框（ORF）分别为1 488 bp和1 485 bp，分别编码495和494个氨基酸。Southern杂交分析表明，TmDGAT 1a和TmDGAT 1b在T.蒙古栎基因组TmDGAT 1a和TmDGAT 1b除了在茎、叶和根等不同组织中普遍表达外，还受到高盐、干旱和渗透胁迫的强烈诱导，导致T.蒙古试管苗通过恢复突变宿主的DGAT活性以产生TAG，在酵母H1246四重突变体（DGA1、LRO1、ARE1、ARE2）中证实了TmDGAT 1a和TmDGAT 1b活性。TmDGAT 1a和TmDGAT 1b在大豆毛状根和T.蒙古愈伤组织都导致了油含量的增加（范围从37%到108%），伴随着脂肪酸谱的改变。
Two cDNAs encoding putative type 1 acyl-CoA: diacylglycerol acyltransferases (DGAT1, EC 2.3.1.20), were cloned from Tetraena mongolica, an extreme xerophyte with high oil content in the stems. The 1 488-bp and 1 485-bp of the open reading frame (ORF) of the two cDNAs, designated as TmDGAT1a and TmDGAT1b, were both predicted to encode proteins of 495 and 494 amino acids, respectively. Southern blot analysis revealed that TmDGAT1a and TmDGAT1b both had low copy numbers in the T. mongolica genome. In addition to ubiquitous expression with different intensity in different tissues, including stems, leaves and roots, TmDGAT1a and TmDGAT1b, were found to be strongly induced by high salinity, drought and osmotic stress, resulting in a remarkable increase of triacylglycerol (TAG) accumulation in T. mongolica plantlets. TmDGAT1a and TmDGAT1b activities were confirmed in the yeast H1246 quadruple mutant (DGA1, LRO1, ARE1, ARE2) by restoring DGAT activity of the mutant host to produce TAG. Overexpression of TmDGAT1a and TmDGAT1b in soybean hairy roots as well as in T. mongolica calli both resulted in an increase in oil content (ranging from 37% to 108%), accompanied by altered fatty acid profiles.