Comparison of relative NA2 mRNA accumulation measurement by qRT-PCR. qRT-PCR was carried out on mRNA extracted from multiple organs. Relative expression was obtained by normalization to the expression level of molybdenum cofactor (GRMZM2G067176) as an internal standard. Samples are indicated on the x axis: FN, 0.25-cm segment containing the first stem node of etiolated seedlings at 5 DAG; M, mesocotyl tissue of 5-DAG etiolated seedlings; CO, coleoptile of 5-DAG etiolated seedlings; TL, true leaves of 5-DAG etiolated seedlings; SM, shoot meristem and surrounding tissue of 9-DAG plants; R, roots of 9-DAG plants; C3, collar of the third leaf from 9-DAG plants; B3, blade from the third leaf of 9-DAG plants; C13, collar of the 13th leaf at maturity; S, stem segment from V7-stage plants; IE, immature ears 0.5 to 2.5 cm in length at the time of harvest; ME, mature ear sampled at silk emergence; IT, immature tassel 0.5 to 2.5 cm in length at the time of harvest; MT, mature tassel sampled at anthesis. Histogram height is proportional to the mean, and error bars indicate sd. Three biological replicates were run in three technical replications each for each sample. Lowercase letters indicate connecting letter report as determined by ANOVA with a posthoc analysis using the Holm-Sidak algorithm with P < 0.05. Samples that share the same letter do not differ statistically, whereas samples that are not connected by the same letter are statistically different.