Selectable tolerance to herbicides by mutated acetolactate synthase genes integrated into the chloroplast genome of tobacco
Selectable tolerance to herbicides by mutated acetolactate synthase genes integrated into the chloroplast genome of tobacco
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DOI：
10.1104/pp.108.120519
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发表时间：
2008-08-01
期刊：
影响因子：
7.4
通讯作者：
Kobayashi, Hirokazu
中科院分区：
文献类型：
--
作者：
Shimizu, Masanori;Goto, Maki;Kobayashi, Hirokazu
转基因（GM）作物生产策略的前提是（1）避免田间基因转移； （二）利用植物等可食用生物的基因； (3)防止抗除草剂杂草的出现； (4)维持转基因而不阻碍植物细胞繁殖。为此，我们开发了一种利用乙酰乳酸合酶（ALS）进行叶绿体转化的新型载体系统。 ALS 催化支链氨基酸生物合成的第一步，其酶活性会被某些类别的除草剂抑制。我们生成了一系列拟南芥 (Arabidopsis thaliana) 突变的 ALS (mALS) 基因，并通过粒子轰击将具有 mALS 和氨基糖苷 3'-腺苷酸转移酶基因 (aadA) 的构建体引入烟草 (Nicotiana tabacum) 叶绿体基因组中。利用其对壮观霉素的抗性来选择转质体植物。使用转质体植物的叶子通过比色测定检查除草剂对转质体 mALS 活性的影响。我们发现转质体 G121A、A122V 和 P197S 植物分别对嘧啶基羧酸盐、咪唑啉酮和磺酰脲/嘧啶基羧酸盐除草剂具有特异性耐受性。具有 mALS 的转质体植物能够在各种除草剂存在下生长，从而证实了 mALS 与相关除草剂抗性之间的关系。我们的结果表明，整合到叶绿体基因组中的 mALS 基因是有用的可持续标记，其功能是排除转基因以外的植物，同时维持转质体作物。这项调查表明，使用（1）一系列赋予除草剂特异性抗性的mALS和（2）采用除草剂轮换的策略，可以对种植转基因作物的田间杂草进行抗性管理。
Strategies employed for the production of genetically modified ( GM) crops are premised on ( 1) the avoidance of gene transfer in the field; ( 2) the use of genes derived from edible organisms such as plants; ( 3) preventing the appearance of herbicideresistant weeds; and ( 4) maintaining transgenes without obstructing plant cell propagation. To this end, we developed a novel vector system for chloroplast transformation with acetolactate synthase ( ALS). ALS catalyzes the first step in the biosynthesis of the branched amino acids, and its enzymatic activity is inhibited by certain classes of herbicides. We generated a series of Arabidopsis ( Arabidopsis thaliana) mutated ALS (mALS) genes and introduced constructs with mALS and the aminoglycoside 3'-adenyltransferase gene ( aadA) into the tobacco ( Nicotiana tabacum) chloroplast genome by particle bombardment. Trans-plastomic plants were selected using their resistance to spectinomycin. The effects of herbicides on transplastomic mALS activity were examined by a colorimetric assay using the leaves of transplastomic plants. We found that transplastomic G121A, A122V, and P197S plants were specifically tolerant to pyrimidinylcarboxylate, imidazolinon, and sulfonylurea/pyrimidinylcarboxylate herbicides, respectively. Transplastomic plants possessing mALSs were able to grow in the presence of various herbicides, thus affirming the relationship between mALSs and the associated resistance to herbicides. Our results show that mALS genes integrated into the chloroplast genome are useful sustainable markers that function to exclude plants other than those that are GM while maintaining transplastomic crops. This investigation suggests that the resistance management of weeds in the field amid growing GM crops is possible using ( 1) a series of mALSs that confer specific resistance to herbicides and ( 2) a strategy that employs herbicide rotation.