Fig. 8.

Zmscr1;Zmscr1h mutants form altered ratios of rank 1 to rank 2 intermediate veins. (A-H) Representative fresh-cut transverse sections of fully expanded leaf 5 from wild-type [m2m1 segregant (A,E); m2m2 segregant (C,G)] and mutant [Zmscr1-m2;Zmscr1h-m1 (B,F); Zmscr1-m2;Zmscr1h-m2 (D,H)] leaves imaged under UV illumination to show fluorescence associated with lignin. Boxes in A-D indicate areas that are enlarged in E-H, respectively. White arrowheads indicate rank 1 intermediate veins with accompanying lignified sclerenchyma. L indicates a lateral vein. Scale bars: 100 µm. (I) Quantification of the number of different vein types per cm of leaf width. (J) The relative proportions of lateral veins (L, light grey), rank 1 intermediate veins (1, striped) and rank 2 intermediate veins (2, dark grey). Data are mean±s.e.m. (K) Quantification of the ratio of rank 1 to rank 2 intermediate veins. In I and K, means are indicated by red crosses; statistical significance between wild type and mutants was assessed using Student's t-test (two-tailed). ns, no significant difference; *P≤0.05, **P≤0.01, ***P≤0.001. Wild-type (m2m1) data in K are also presented in Fig. 3B. Raw phenotypic data are provided in Table S1.