Figure 3.
Effects of N supply on Casparian strip formation and mineral element profiles in ZmmiR528 knockdown (TM) transgenic maize.
ZmmiR528 knockdown transgenic maize and inbred CZ01 were grown in a hydroponic solution containing 8 mM or 0.04 mM NO3−-N for 3 days.
(A) Casparian strip formation in ZmmiR528 TM transgenic maize as affected by N supply. The area 1.0–1.5 cm from the apex of roots grown under NL or ND was sampled, stained with berberine hemisulfate, and assessed for Casparian strip formation. Casparian strips are indicated by red arrowheads. Numbers below the photographs indicate the percentage of root tips with Casparian strips (% and number of roots that formed Casparian strips/total root number). Scale bars represent 50 μm. Values are means ± SEM. Means with the same letter are not significantly different at P < 0.05 according to the LSD test.
(B and C) Effects of N on Ca, Mn, and Zn concentrations in roots (B) and shoots (C) of ZmmiR528 TM transgenic maize. Values are means ± SD (n = 4). ∗P < 0.05 (Student’s t-test) indicates a significant difference from the control. NL and ND indicate N luxury and N deficiency, respectively.