Transcriptomic analysis of Sorghum bicolor under limited nitrogen condition

Transcriptomic changes of sorghum induced by nitrogen limitation were analyzed RNA sequencing, with the aim of identifying sorghum genes whose expression was modified earlier than morphological changes. Seeds of sorghum (BTx623) were germinated and grown on vermiculite for a week in the culture room maintained at 25?C. Seedlings were transferred to the full-strength Yoshida B hydroponic culture medium [1 mM KCl, 0.25 mM (NH4)2 HPO4, 0.5 mM MgSO4, 1 mM Ca(NO3)2, 0.1 mM Fe(III)-EDTA, 46 ?M B(OH)3, 9 mM MnCl2, 0.3 mM CuSO4, 0.8 mM ZnSO4, and 0.1 mM (NH4)2Mo7O24] and cultured for a week. The 2-week-old plants were then transferred to low N or control medium. The control medium was the Yoshida B culture solution. The low N medium contained N at 1/10 of control (0.05 mM NH4+ and 0.2 mM NO3-), while the concentration of calcium and potassium were maintained at the same level as control using CaCl2 and KH2PO4, respectively.