The glutamate dehydrogenase gene gdhA increased the resistance of tobacco to glufosinate
The glutamate dehydrogenase gene gdhA increased the resistance of tobacco to glufosinate
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DOI：
10.1111/j.1365-3180.2004.00411.x
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发表时间：
2004-08-01
期刊：
影响因子：
1.7
通讯作者：
Lightfoot, DA
中科院分区：
文献类型：
--
作者：
Nolte, SA;Young, BG;Lightfoot, DA
来自大肠杆菌的基因gdhA编码NADPH依赖性谷氨酸脱氢酶（GDH），在转基因植物中指导一种新的途径，允许增加铵同化。草铵膦通过不可逆地抑制谷氨酸合成酶（GS）导致随后的GS相关过程的破坏而导致植物死亡，从而导致铵升高和光呼吸的破坏。因此，据推测，gdhA转化的植物可能通过改变GDH定向途径和随后相关过程的活性而表现出对草铵膦的新抗性机制。在温室中进行研究以评估含有gdhA基因的烟草植物对草铵膦的抗性。研究了五个烟草基因型品系，包括未转化的对照品系、阳性对照品系和三个具有由gdhA基因指导的增加的GDH活性水平的转化品系。与未转化的对照相比，用gdhA基因转化的植物表达对草铵膦的抗性水平（GR（50））增加多达6倍，其抗性比用bar基因转化的植物低100倍。GDH活性与抗除草剂水平呈高度相关（r（2）= 0.9903）。因此，E. coligdhA基因在植物转化中的表达可以为草铵膦抗性提供额外的机制。
The gene gdhA from Escherichia coli, that encodes a NADPH-dependent glutamate dehydrogenase (GDH), directs a novel pathway in transgenic plants that allows an increase in ammonium assimilation. Glufosinate leads to plant death by the irreversible inhibition of glutamate synthetase (GS) leading to a disruption of subsequent GS-related processes resulting in elevated ammonium and disruption of photorespiration. Therefore, it was speculated that the gdhA-transformed plants may exhibit a novel mechanism of resistance to glufosinate by altered activity of the GDH-directed pathway(s) and subsequently related processes. Studies were conducted in the greenhouse to evaluate the resistance of tobacco plants containing the gdhA gene to glufosinate. Five tobacco genotype lines were investigated including a non-transformed control line, a positive control line and three transformed lines with levels of increasing GDH activity directed by the gdhA gene. Plants transformed with the gdhA gene expressed up to six times increased level of resistance (GR(50)) to glufosinate compared with the non-transformed control, which is 100 times less resistant than plants transformed with the bar gene. The GDH activity among lines was highly correlated (r(2) = 0.9903) with the level of herbicide resistance. Thus, the use of the E. coli gdhA gene in plant transformations can provide an additional mechanism for resistance to glufosinate.