Fig. 3

MP Expression, ATHB8 Expression Domains and Levels, and Vein Network Formation. (A–D,G–J) Top right: genotype. (A–D) First leaves 4 DAG. Confocal laser scanning microscopy. Dashed white line: leaf outline. ATHB8::nYFP expression (look-up table — ramp in E — visualizes expression levels). (F) ATHB8::nYFP expression level per cell expressed as mean gray value ± SE, ATHB8::nYFP expression domain length expressed as mean number of cells ± SE, and ATHB8::nYFP expression levels per domain expressed as mean gray value ± SE. Difference between mp-U55 and WT, between mp-11 and WT, and between MP::MP and WT was significant at P < 0.001 (***) by F-test and t-test with Bonferroni correction. Sample sizes: 25 (WT), 72 (mp-U55), 27 (mp-11), or 24 (MP::MP) leaves; 345 (WT), 128 (mp-U55), 325 (mp-11), or 219 (MP::MP) vein cell nuclei, and 513 (MP::MP) flanking cell nuclei. (G–J) Dark-field illumination of cleared first leaves 14 DAG. (K) Cardinality index, connectivity index, and continuity index (mean ± SE) as defined in [20] and Methods; cyclicity index (mean ± SE) as defined in Methods. Difference between mp-U55 and WT cardinality indices, between mp-11 and WT cardinality indices, between mp-U55 and WT continuity indices, between mp-11 and WT continuity indices, between mp-U55 and WT connectivity indices, between mp-11 and WT connectivity indices, between MP::MP and WT connectivity indices, between mp-U55 and WT cyclicity indices, between mp-11 and WT cyclicity indices, and between MP::MP and WT cyclicity indices was significant at P < 0.05 (*) or P < 0.001 (***) by F-test and t-test with Bonferroni correction. Sample sizes: WT, 39; mp-U55, 59; mp-11, 44; MP::MP, 41. Scale bars: (A–D) 25 μm; (G-J) 0.5 mm