Fig 4. Genetic interactions between KNOX1 and KNOX2 genes.

(A-B) Morphology of _pro 35S:amiR ¹⁵⁹ -KNAT345–1 plants in wild-type (A) and bp-9 knat2–5 knat6–1 mutant (B) backgrounds. 6 weeks-old plants are shown. (C-E) F1 plants expressing both _pro BLS:STM and _pro 35S:amiR ¹⁵⁹ -KNAT345–1 constructs (D) show a stronger serration phenotype than either parental line (C, E). All plants shown are hemizygous for the transgene(s) and 2 weeks old. (F-G) Morphology of knat3 knat5 (F) and knat2–5 knat3 knat5 knat6–1 (G) plants grown for 5 weeks. (H) A representative bp knat345 rosette leaf with deeply lobed margins, as seen in knat345. (I-J) The bp inflorescence phenotype (I) is observed in bp knat345 infloresences (J), indicating additive effects of mutations in these genes. (H-J) Plants were grown for 2 months. (K-P) KNOX1 reporter expression in wild-type (K-M) and knat3 knat5 (N-P) plants. Shown are _pro BP:GUS expression in 17 days-old plants (K, N), _pro KNAT2:GUS expression in 20 days-old plants (L, O), and _pro STM:GUS expression in 21 days-old plants (M, P). No ectopic expression of _pro BP:GUS was detected during stages of leaf development when lobes are forming in knat3 knat5 plants (K, N), but ectopic expression was observed at leaf serration tips after their development. _pro KNAT2:GUS and _pro STM:GUS expression patterns in knat3 knat5 plants are similar to those in wild-type plants (L-M, O-P). Occasionally, longer incubation detected _pro STM:GUS activity in the sinus of wild-type and mutant leaves (M). _pro KNAT2:GUS and _pro STM:GUS were analyzed in the mixed genetic background (refer to S1 Table for details), and other plants are in the Col background. Scale bars in I, J, 3 mm, K, L, N, 100 μm and in M, O, P, 200 μm.