Control of plant phenylpropanoid metabolism by heat sensitive promoter

本研究的目的是利用热激诱导型启动子与植物基因组中的插入基因相连接，控制植物的次生代谢。使用烟草（Nicotiana plumbaginifolia）作为模式植物，并且使用辣椒（Capsicum frutescens）作为作物的实例。拟南芥热休克蛋白（HSP）18.2启动子与大肠杆菌GUS基因的嵌合体基因。coli或欧芹苯丙氨酸解氨酶（PAL）基因，并将其导入N.白花丹研究了热激处理对它们的诱导作用。毛状根经40℃热激处理2 h后，GUS活性得到诱导，此诱导物在3-5个月内稳定。第一次热激处理后6天，诱导细胞再生。辣椒毛状根经38-44℃热激处理2 h后，GUS活性无明显变化。欧芹毛状根经热激处理后PAL活性也没有变化。白花丹叶片的PAL活性有时会暂时下降。这些现象表明，外源PAL基因诱导产生了共抑制。本实验中没有观察到PAL活性的预期增加，但可以说，通过植物毛状根培养物的热处理，利用共抑制来改变代谢通量是可能的。

The aim of this research is to control plant secondary metabolism by using heat-shock inducible promoter which is connected to the inserted gene in plant genome. Nicotiana plumbaginifolia was used as a model plant and chilli pepper(Capsicum frutescens) was used for the example of a crop. Chimera genes of Arabidopsis heat-shock protein(HSP)18.2 promoter and β-glucronidase(GUS) gene from E. coli or parsley phenylalanineammonia-lyase(PAL) gene were constructed and they were introduced into the hairy roots of N. plumbaginifolia. Their inducibility by heat shock treatment was investigated. GUS activity was induced by heat shock treatment at 40℃ for 2 hours on hairy roots and this inducibility was stable for 3-5 months. The inducibility was reproduced on 6 days after first heat shock treatment. However, GUS activity showed no change by heat shock treatment at 38-44℃ for 2 hours in hairy roots of chilli pepper. A parsley PAL activity also showed no change after heat shock treatment on hairy roots of N. plumbaginifolia, and sometimes the PAL activity decreased temporaly. These phenomena indicated that induced foreign PAL gene caused a co-supression. Intended increase of PAL activity was not observbed in this experiment, but it can be said that metabolism flux change using co-supression is possible by heat treatment of plant hairy root culture.