Beet Glutamine Synthetase Gene Promoter Cloned

Nitrogen assimilation is very important for growth and development of plants. Inorganic nitrogen must be assimilated as organic nitrogen which can be absorbed and used by plants. Glutamine synthetase is a key enzyme during this process.Promoter is a kind of DNA region or sequence that can combine with RNA Polymerase and other transcription factors. The promoter-analysis is a very important and efficient method used in genes function-analysis and specific expression research.The experiment aimed to acquire the promoter of glutamine synthetase gene (GS). DNA was extracted from sugar beet leaves as template. According to the sequence of Genes , specific primers were designed for LA-PCR to obtain upstream sequence of GS gene,then promoter gene was amplified via PCR method .The PCR product was ligated in T vector , transformed into competent cell of E.coli and then sequenced . A fragment containing 828 bps of upstream sequence 5'of the GS gene start codon was isolated using LA-PCR method . The 828 bps 5'flanking sequence of the GS gene was used to analyze cis-regulatory DNA elements in plant using TSSP and PLACE on-line software .The results indicated that TATA-box (TATAAT) is located at 30-35bp of the ATG stat codon .GS gene promoter contains 36 putative cis-elements.In this experiment, the regulatory region of GS gene was separated firstly from sugar beet, which provides molecular biological foundation for GS gene expression, regulation and implement of high ammonia assimilation in sugar beet.