Nitrogen-efficient rice over-expressing alanine aminotransferase at three different N concentrations

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