Abstract:

The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5′end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.

重组色氨酸脱羧酶在烟草不同亚细胞区室的表达

王淼^1*  李秋荣²  Stefano Di DIORE³  Rainer FISCHER³

(1.中国科学院沈阳应用生态研究所,沈阳,110016；2.沈阳军区总医院,沈阳,110016; 3.Botanical Institute of Rjeinisch -Westfaliusch Techniische Hochschule Aachen,D-52074 Aachen ,Germany)

摘要：将萜烯类吲哚生物碱代谢关键酶--色氨酸脱羧酶（TDC）的编码基因转到烟草（Nicotiana tabacum L.)植物体内，标定在不同的亚细胞区室表达。通过蛋白免疫印迹法和色胺在植物体内的累积量测定分析，对转基因植物进行筛选。结果表明，TDC在叶绿体和胞液中高效表达，TDC在叶绿体中的表达水平最高，高于在胞液中的表达，在内质网和液泡中表达水平很低，用蛋白免疫印迹法未检出。

关键词 色氨酸脱羧酶 生物碱代谢途径 烟草 亚细胞区室

*通讯作者 Email: wangmiao@iae.ac.cn

Key words: tryptophan decarboxylase, alkaloids biosynthetic pathway, Nicotiana tabacum, subcellular compartment