(A) Cleared SAMs from wild type (WT), Zmcrn, fea2, and Zmcrn;fea2 double-mutant plants. SAMs from Zmcrn and fea2 plants were significantly wider than in wild type (double-headed arrows), but SAM size was not significantly different between fea2 and Zmcrn;fea2 double mutants, SAM diameter was quantified (B). (C) Ear meristems of fea2;Zmcrn double mutants resemble fea2 single mutants. (D) Cleared SAMs from wild type, Zmcrn, ct2, and Zmcrn;ct2 double-mutant plants. SAMs from Zmcrn and ct2 plants were significantly wider than in wild type, and were additively increased in Zmcrn;ct2 double mutants; SAM diameter was quantified (E). (F) Zmcrn;ct2 double mutants had enhanced fasciation of ear primordia. Scale bars: 100 μm in A and D, 500 μm in C and F. n = 30 (B, E) plants for each genotype. Data in B and E are shown by box plots. The mean values as well as the relative % to the WT control are listed. ‘***': P value < 0.0001, two-tailed, two-sample t test, 'NS’: not significant.