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 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. 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:The studies of rice nitrogen concentration on the expression of miRNA so far are mostly limited to the exogenous nitrogen, leaving the effect of endogenous nitrogen largely unexplored. OsNAR2.1 is a high-affinity nitrate transporter partner protein which plays a central role in nitrate absorption and translocation in rice. The expression of OsNAR2.1 could influence the concentration of the endogenous nitrogen in rice. We showed that the expression and production of miRNA in rice can be influenced by manipulating the endogenous nitrogen concentration via OsNAR2.1 transgenic lines. The small RNA expressed differently in two transgenic rice lines (nitrogen efficient line with overexpression of OsNAR2.1 (Ov199), nitrogen-inefficient line with knockdown OsNAR2.1 by RNAi (RNAi)) compared to the wild-type (NP). Comparative hierarchical clustering expression pattern analysis revealed that the expression profiles of mature miRNA in both transgenic lines were different from NP.
Project description:Intensive application of inorganic nitrogen underlies marked increase in crop production yet imposes detrimental impact on ecosystems, hence it is crucial for future sustainable agriculture to improve nitrogen-use efficiency (NUE). Here we report the genetic basis of NUE associated with the local soil adaptation in rice. With a diverse rice germplasm panel collected from different ecogeographic regions, we performed genome-wide association study on tillering response to nitrogen (TRN), the most correlated trait with NUE of rice, and identified OsTCP19 as a modulator of TRN via transcriptionally responding to nitrogen and targeting to Dwarf and Low-Tillering (DLT), a tiller-promoting gene. A 29-bp InDel in OsTCP19 promoter confers differential transcription response to nitrogen and TRN variation among rice varieties. The high-TRN allele of OsTCP19 (OsTCP19-H) is prevalent in wild rice population, but largely lost in modern cultivars correlating with increased local soil nitrogen content, suggesting that it might have contributed to geographic adaptation in rice. Introgression of OsTCP19-H into modern rice cultivars boosts grain yield and NUE under low or moderate nitrogen levels, demonstrating its enormous potential for rice breeding and environment amelioration through reducing nitrogen application.
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:Nitrogen is major nutrient for plant growth. Two forms for inorganic nitrogen are available for plant, ammonium and nitrate. External status of them affects largely plant growth and production. Generally, root is a sole organ to uptake nitrogen. Hence, identifying regulatory genes depend on nitrogen status in roots is important to improve sustainable production or rice. To isolate the candidate gene, array experiments were performed. Consequently, we isolated genes which showed marked accumulation in deficient and sufficient concentrations of ammonium in roots.