Fig. 4. Genetic interaction between myb3r1, myb3r4 and kn. (A) Effects of heterozygous mutation of kn on the severity of cytokinesis defects. Frequency of cytokinesis-defective stomata and epidermal cells were determined in the silique valve of the plants with the indicated genotypes. Data for myb3r1/myb3r1 myb3r4/myb3r4 KN/kn plants are not available because these plants do not produce siliques. Columns represent mean values; error bars represent s.d. (B-D) Defective cytokinesis in myb3r1/myb3r1 myb3r4/myb3r4 KN/kn plants. (B) Pavement epidermal cells and (C) palisade cells in rosette leaves, showing cell wall stubs (arrowheads). (D) Enlarged cells (arrowhead) with multiple nuclei (asterisks) in root epidermal cells. Scale bars in B-D, 20 µm. (E) Transcript levels of KN in plants with various allele combinations of MYB3R1, MYB3R4 and KN genes. All measurements were performed on inflorescences containing young flower buds in mature plants. Expression levels were determined by real-time quantitative RT-PCR and normalized relative to those in wild-type plants. Columns represent mean values; error bars represent s.d.