Fig. 5.

Mutation in OsPHR3 affects concentration and redistribution of NO₃⁻ in young and old leaf blades. Seeds of the WT and mutants (osphr3–1 and 3–2) were grown hydroponically in IRRI solution for 3 weeks and then deprived of N for 3 d. a Seedlings were then transferred to H NO₃⁻ and L NO₃⁻ for 7 d. Young leaf blade (YLB) and old leaf blade (OLB) were harvested and assayed for NO₃⁻ concentration. b For determining ¹⁵NO₃⁻ redistribution ratio, the oldest leaf blade of the WT and mutant seedlings were incubated in a solution containing ¹⁵N-NO₃⁻ (5 mM) for 5 h. values are means ±SE (n = 5) and different letters on the histograms indicate that the values differ significantly (P < 0.05, one-way ANOVA). FW, fresh weight