Glutamine synthetase (GS; EC 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) catalyzes the ATP-dependent addition of ammonium (NH4 +) to the γ-carboxyl group of glutamate and produces glutamine. The enzyme is the product of multiple genes with complex promoters that ensure the transcriptional regulation of the genes in an organ‐ and tissue‐specific manner and in response to a number of environmental variables affecting the nutritional status of the plant cell. In the present study we tested

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... r the presence of highly conserved non-coding sequences (CNSs) in the 1000-bp promoter region by analyzing upstream promoter sequences (counted from the translation initiation codon), of Glutamine Synthetase (GS1;5) and its orthologous genes. A comparative genome-wide bioinformatic analysis performed for identification of evolutionarily preserved regulatory sequences has revealed highly conserved upstream non-coding sequences (CNSs) within 1000-bp promoter region by analyzing upstream promoter sequences (counted from the translation initiation codon), of GS1;5 from Arabidopsis thaliana and its orthologous genes in various plant species. Two consensus sequences are predicted by sequence logo at the position of -880 bp to -890 bp (CNS1) and -522 bp to -549 bp (CNS2) of Arabidopsis promoter region counted from the ATG. Thus identified putative cis-regulatory elements in the promoter region of GS1;5 are expected to allow physical binding of upstream regulatory proteins which are yet to be known, but controlling the senescencedependent expression of this gene at promoter level in major plant species, under influence of environmental cues to initiate nitrogen remobilization from source to sink.