The expression of tga1a gene from tobacco affects the expression of exogenous gene in transgenic plant  

作　　者：路子显 常团结 李旭刚 徐军望 李慧芬 陈宛新 冯德江 肖桂芳 朱祯 

机构地区：[1]Institute of Genetics, Chinese Academy of Sciences, Beijing 100101, China

出　　处：《Science China(Life Sciences)》2003年第2期141-152,共12页中国科学（生命科学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China (Grant Nos.39980024;39880023&39989001);heHighTechnology Research and DevelopmentProgramofChina2001AA212041;2001AA222251; 101-06-01-06) and the National Key Fundamental Resear

摘　　要：The DNA-binding protein TGA1a of tobacco can specially interact with the enhancer sequence as-1 (- 83 to - 63) of CaMV35S promoter and show the function of transcriptional acti-vation. In order to study the expression of exogenous gene affected by TGA1a, a trans-acting regulation system was formed by tandem connecting tga1a under the control of the phloem- specific promoter rolC with reporter gene under the control of CaMV35S. Then, the system above was utilized to construct a plant expression vector. Moreover, two plant expression vectors were constructed with the report gene controlled by CaMV35S and rolC promoter respectively as posi-tive controls. Tobacco leaf disc transformed by Agrobacterium-mediated method and transgenic plants were regenerated. It was proved that the reporter gene existed in the genome of transgenic plants by Southern hybridization. The results of GUS activity indicated that the expression of tga1a controlled by rolC remarkably increased the expression of the reporter gene controlled by CaMV35S. GUS activity of transgenic plants containing trans-acting regulation system was higher than that of transgenic plants containing the reporter gene under the control of CaMV35S and rolC respectively, with the highest GUS activity of about tenfolds of two positive controls. Histochemical method demonstrated that GUS staining amassed mainly in phloem tissue of transgenic plants containing the trans-acting regulation system. A new model for arising the expression level and tissue-specific expression of exogenous gene in transgenic plant was established in this study.The DNA-binding protein TGA1a of tobacco can specially interact with the enhancer sequence as-1 (- 83 to - 63) of CaMV35S promoter and show the function of transcriptional acti-vation. In order to study the expression of exogenous gene affected by TGA1a, a trans-acting regulation system was formed by tandem connecting tga1a under the control of the phloem- specific promoter rolC with reporter gene under the control of CaMV35S. Then, the system above was utilized to construct a plant expression vector. Moreover, two plant expression vectors were constructed with the report gene controlled by CaMV35S and rolC promoter respectively as posi-tive controls. Tobacco leaf disc transformed by Agrobacterium-mediated method and transgenic plants were regenerated. It was proved that the reporter gene existed in the genome of transgenic plants by Southern hybridization. The results of GUS activity indicated that the expression of tga1a controlled by rolC remarkably increased the expression of the reporter gene controlled by CaMV35S. GUS activity of transgenic plants containing trans-acting regulation system was higher than that of transgenic plants containing the reporter gene under the control of CaMV35S and rolC respectively, with the highest GUS activity of about tenfolds of two positive controls. Histochemical method demonstrated that GUS staining amassed mainly in phloem tissue of transgenic plants containing the trans-acting regulation system. A new model for arising the expression level and tissue-specific expression of exogenous gene in transgenic plant was established in this study.

关 键 词：GENE EXPRESSION and regulation  DNA-BINDING protein TGA1a  plant transformation  REPORTER gene. 

分 类 号：Q943.2[生物学—植物学]