Nitrogen Cycle Nitrate Transporter NRT1 · High affinity and low Constitutive and nitrate induced NRT2 High affinity · Nitrate inducable ↳ Regulated by .. ↳ development ↳ Diurnal ↳ Sucrose ↳ NHpt ↳ Glutamate . Nitrute Reductuse · Cytoplasmic enzymes NO : nitrate (NOs) reduces the + 2 + > NOztHa to Nitrate (NO2] Regulation Nitrate Reductuse · Plastidic NOc · Electron + be + 8Ht < NHat to ammonium (NH4") + 2H2O from Ferredoxin come photosynthetic ↳ Via ↳ reduces nitrate(NO2T enzyme in Ferredoxin-NADP + Vin NADPH + LFdox chloroplast. reductase >NADP" + IFdred Nitrogen Assimilation 1) GS-GOGAT Two step · · Primary assimilation N- Ammonium : Glutamine Synthetase and Glutamine 2 - Oxogluturate Amino transferase. assimilation released of during generation · Glutamine Synthetase (GS) - - · phenylpropanoid. ATP dependent Plastid and Net flow of NH3 cytoplasmic forms from NHz pool to carbon from TCA. Biosynthesis (-skeleton from Amino and primary N introduces Asparagine · Asn has via (metabolic pathway (black) transamination reaction (red) Synthetase a high W : C ratio Asparagine Synthetuse regulation inversely coordinated Inhibition by high light and Carbohydrate is with GS-GOGAT . · Activated by energy-limited ATP Suturylase · · ATP PP : Sulfurylase Hydrolysis - activation catalyzes ( 33) - = conditions. of 504 reaction lowering activation D