Figure 1. Nitrogen fertilizer triggers OsmiR393 accumulation and overexpression resulting in an increased number of tillers.

(A and D), qRT-PCR (A) and small RNA gel blot (D) analysis of OsmiR393 expression level in ZH11 with elevating NH₄NO₃ levels (A) and in OsmiR393-overexpressing rice lines (OX393) under normal nitrogen (N) levels (1 N) (D). The level of NH₄NO₃ (1.43 mM) in the IRRI nutrient solution³⁸ was set as the normal (1 N) level of N fertilizer; other N levels represent multiples of the 1 N level. Vertical bars in (A) indicate standard error from three individual repeats. Rice U6 was used as an internal control. The asterisk in (A) indicates a mean fold change of greater than 2 vs the 0 N condition. (B,C) and (E,F), Tiller numbers of ZH11 with elevating NH₄NO₃ levels (B,C) and in OsmiR393-overexpressing rice plants with a normal N concentration (1 N) (E,F) respectively, when plants were grown in a pot. Scale bar = 2 cm in (B) and (E). Tiller numbers in (C) and (F) were counted and analysed in excel. Vertical bars in (C) and (F) indicate standard error (n ≥ 15 plants for every sample and each experiment was repeated three times). The asterisk indicates significant differences (*P ≤ 0.05 and **P ≤ 0.01) compared to ZH11 at 0 N (C), and at 1 N (F) as determined by a t-test.