ABSTRACT: Improving Nitrogen Use Efficiency through Alteration of the Carbohydrate Metabolism Pathway from the Overexpression of Alanine Aminotransferase
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We use biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa.
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We are using biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa.
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We are using biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa. Wildtype rice (Nipponbare) and three independent OsANT1:HvAlaAT rice transgenic lines (AGR1/7, AGR1/8 and AGR3/8) were grown hydroponically with 5mM NH4+ as the nitrogen source, to the reproductive stage. RNA samples were taken at active tillering, maximum tillering and end-of-tillering stages from root and shoot, at mid-day of the plants' day/night cycle. The RNA from root and shoot at maxiumum tillering was used for microarray analysis. Please read Beatty et al., 2009, Plant Biotechnology Journal 7, pp562-576 for further details..
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We use biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa. Transcriptome data from the roots and shoots of rice plants at maximum tillering, grown hydroponically on either 0.5, 2 or 5 mM NH4+ as the nitrogen source. Wildtype rice (Nipponbare) and two independent OsANT1:HvAlaAT rice transgenic lines (AGR1/7, and AGR3/8) were grown hydroponically with either 0.5, 2 or 5mM NH4+ as the nitrogen source, to the reproductive stage. Tissue samples were taken at active and maximum tillering from root and shoot, at mid-day of the plants' day/night cycle. The RNA from root and shoot at maxiumum tillering was used for mcroarray analysis. Please read Beatty et al., 2009, PLant Biotechnology Journal 7, pp562-576 for detailed about these transgenic lines. The results from this variable N study were reported in a manuscript submitted to Botany, July 2013
Project description:The Leucine-responsive Regulatory Protein (Lrp) family is a widespread family of regulatory transcription factors in prokaryotes. BarR is an Lrp-like transcription factor in the model archaeon Sulfolobus acidocaldarius that activates the expression of a -alanine aminotransferase gene, which is involved in -alanine degradation. In contrast to classical Lrp-like transcription factors, BarR is not responsive to any of the -amino acids but interacts specifically with -alanine. Besides the juxtaposed -alanine aminotransferase gene, other regulatory targets of BarR have not yet been identified although -alanine is the precursor of coenzyme A and thus an important central metabolite. The aim of this study is to extend the knowledge of the DNA-binding characteristics of BarR and of its corresponding regulon from a local to a genome-wide perspective.