Fig 2. ZCN12 is a novel maize florigen co-regulated with ZCN8.

ZCN12 expression correlates with anthesis time (platform experiment 2014), (A), and with ZCN8 expression (B). Genotypic values are BLUEs. Pearson’s correlation coefficients are indicated with their significance (***, p < 10⁻⁴). The red triangle represents genotypic values for the reference line B73. In (A) and (B), n = 173. (C) Arabidopsis T1 plants overexpressing ZCN12 but not ZCN8 show an extreme early flowering phenotype compared to empty vector transformation (Vect.); plants were photographed 3 weeks after sowing, horizontal bar, 1 cm. (D) ZCN8 and ZCN12 T1 over-expressing plants are earlier flowering than wild type (p < 0.01, one-way ANOVA with post-hoc Tukey HSD test). Horizontal bars, mean values of rosette leaves number. n = 37, 38 and 14 for, respectively, 35S:HA:ZCN8 35S:HA:ZCN12 and wild type (empty vector). (E) RT-PCR analysis on ZCN8/12 transcripts derived from independent T2 transgenic plants of the indicated genotypes. Numbers on the left are kb based on DNA ladder (Mk) migration. Amplification of vectors (Vect) harbouring genomic versions of ZCN8 and ZCN12 afforded a positive control whereas untransformed wild type and no DNA reactions (-) were used as negative controls. Actin expression was used for normalization (lower panel). Amplifications were conducted for 25 cycles.