title: Asparagine synthetase gene TaASN1 from wheat is up-regulated by salt stress, osmotic stress and ABA.
abstract: Differences in gene expression between salinity stressed and normally grown wheat seedlings were compared by the differential display (DD) technique. One DD-derived cDNA clone was characterized as a partial sequence of the wheat asparagine ynthetase (AS) gene by sequence analysis and homology search of GenBank databases. Two AS genes of wheat, TaASN1 and TaASN2, were further isolated by the RT-PCR approach. Comparison of the deduced polypeptide of TaASN1 and TaASN2 with AS proteins from other organisms revealed several homologous regions, in particular, the conserved glutamine binding sites and Class-II Glutamine amidotransferases domain. The functionality of TaASN1 was demonstrated by complementing an Escherichia coli asparagine auxotroph. TaASN1 transcripts were detected in roots, shoots, anthers and young spikes by RT-PCR analysis. Abundance of TaASN1 mRNA in young spikes and anthers was higher than that in shoots and roots under normal growth conditions. TaASN1 was dramatically induced by salinity, osmotic stress and exogenous abscisic acid (ABA) in wheat seedlings. TaASN2 transcripts were very low in all detected tissues and conditions and were only slightly induced by ABA in roots.
authors.affiliation: Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, People's Republic of China.
authors.forename: Huabo
authors.initials: H
authors.lastname: Wang
authors.forename: Dongcheng
authors.initials: D
authors.lastname: Liu
authors.forename: Jiazhu
authors.initials: J
authors.lastname: Sun
authors.forename: Aimin
authors.initials: A
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D001217:Aspartate-Ammonia Ligase / Q000096:biosynthesis* / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010802:Phylogeny; D035261:Plant Components, Aerial / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology*; D013997:Time Factors; D014908:Triticum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water; D012965:Sodium Chloride; D000040:Abscisic Acid; D001217:Aspartate-Ammonia Ligase