拟南芥生长素受体基因TIR1启动子的初步分析

Function analysis of the promoter for an TIR1 gene from Arabidopsis auxin receptor

以野生型拟南芥(Arabidopsis Columbia)基因组DNA为模板,通过PCR扩增得到拟南芥生长素受体基因TIR1启动子的5个不同长度的系列缺失片段,将这些片断分别克隆到PGM-T载体上。序列分析表明,该启动子系列缺失片段的大小分别为2008bp、1524bp、939bp、532bp和321bp。与已报道的序列完全相同。将不同长度的启动子克隆片断分别与GUS基因融合,构建成表达载体后,在烟草叶片中作遗传转化。分析结果显示:不同长度的启动子片段已整合到烟草基因组中并有GUS酶活性存在,且不同长度启动子片段的表达活性有较明显差异。

As one of the most important plant hormones, auxin regulates diverse aspects of plant growth and development. Auxin receptor is the key component of auxin signaling pathway, elucidating its structure, function and expression pattern will be helpful to understand how auxin works. Transcription regulation is major level of plant gene expression and understanding of various cis-and transacting elements, esp promoter, is one of core issues of plant genetics. Since the F-box protein TIR1 had been proved to be an auxin receptor, and there is no study about its expression pattern, esp study on its promoter. This study is designed to enhance understanding of TIR1 promoter＇s structure and function. First, TIR1 promotor was amplified from Arabidopsis Columbia genome by polymerase chain reaction and cloned into PGM-T vector; Sequence analysis showed that the cloned fragment respectively contained 2008bp, 1524bp, 939bp, 532bp and 321bp. Serial deletion mutational promoter vectors were constructed and transformed into tobacco by leaf disk method for stable expression analysis. PCR screen positive plantlet and GUS staining to locate core promoter sequence and analyze part cisacting elements. Transient expression analysis show： The GUS activity was detected in tobacco leaf and the expression activity of direrent length promoter fragment have evident difference.