Figure 7From: Effects of salt stress on ion balance and nitrogen metabolism of old and young leaves in rice (Oryza sativa L.)Ion balance and nitrogen metabolism responses of old leaves of rice seedlings under salt stress. Under salt stress, old leaves accumulates much higher concentrations of Na+, Cl− and NO3− than young leaves. Under salt stress, up-regulation of OsHKT1;1, OsHAK10 and OsHAK16 advances the accumulation of Na+ in old leaves, and increased OsNHX1 expression contributes to Na+ compartmentalization in old leaves. In addition, lower expression of OsHKT1;5 and OsSOS1 in old leaves decreases frequency of retrieving Na+ from old leaf cells. Excess of Na+ weakens GOGAT/GS pathway and elevates GDH pathway in old leaves. The up-regulation of OsNRT1;2, a gene coding nitrate transporter, advances the accumulation of NO3− in the old leaves of salt stressed-rice.Back to article page