Adaptation of cucumber seedlings to low temperature stress by reducing nitrate to ammonium during it’s transportation

Abstract Background Low temperature severely depresses the uptake, translocation from root to shoot, and metabolism of nitrate ammonium in thermophilic plants such as cucumber ( Cucumis sativus ). Plant growth is inhibited accordingly. However, availability information on effects low nitrogen transport remains limited. Results Using non-invasive micro-test technology, net (NO 3 ? ) (NH 4 + fluxes hair zone vascular bundles primary root, stem, petiole, midrib, lateral vein, shoot tip seedlings under normal (NT; 26 °C) (LT; 8 treatment were analyzed. Under LT treatment, NO flux rate decreased, whereas NH increased. Accordingly, relative expression CsNRT1.4a petiole midrib was down-regulated, CsAMT1.2a – 1.2c up-regulated. The results 15 N isotope tracing showed that -N uptake decreased significantly compared with NT concentration proportion both distributed decreased. actual reductase activity (NRA act did not change significantly, NRA stem increased by 113.2 96.2%, respectively. Conclusions higher leaves young tissues may reflect which result a being reduced during upward transportation . contribute an improved understanding mechanism changes response low-temperature stress.