PROMOTERS AND THEIR APPLICATION IN PLANT GENE TECHNOLOGY

  • Lê Thị Thu Hiền
  • Trần Thị Phương Liên

Abstract

The term 'promoter' is used to designate a region in the genome sequence upstream, or 5' end, of a gene transcription start site (TSS), which is defined as position + 1. Promoters have complex structures and contain various distinct sequence elements that function in the recruitment of protein factors facilitating the transcription of the protein-coding region of the gene. One essential element is the TA TA box that serves as a binding place for transcription initiation factors and is typically located around -30 bp upstream of the TSS. Another common element is CCAAT box. In plants, the CCAA T box may have a different consensus sequence and has been tenned as the AGGA box. Besides TAT A and CCAA T boxes, virtually all eukaryotic promoters contain additional upstream DNA  sequences that are variously known as enhancers or upstream activating sequences. Such sequences are variable in length and may extend from around 100 to 1,000 bp or more upstream of the TSS. A promoter can either be constitutive or spatiall temporal specific according to its ability to express the gene that it controls. In the field of plant gene technology, promoters have been widely used for the expression of exogenous genes in transgenic plants. The most famous are the CaMV358, CaMVI98 and nopaline synthase (NOS) promoters. To date, many attempts have been made to isolate and construct specific or novel promoters with high level of expression or with precisely controlled activities for plant genetic engineering applications. Besides that, a number of databases with infonnation on promoter sequences and their functions and of promoter design software programs have been developed and applied. In Vietnam, the isolation and characterization of promoters from natural resources for construction of plant expression vectors are under development.

Tác giả

Lê Thị Thu Hiền
Trần Thị Phương Liên
điểm /   đánh giá
Published
2011-11-28
Section
Articles