Supplemental Data

Files in this Data Supplement:

• Supplemental Figure 1 - Alignment of Blind-like protein sequences. The conserved N-terminal domains (amino acids 1 to 118) of the six Arabidopsis MYB proteins (At MYB36, 37, 38, 68, 84, 87) showing the highest sequence similarity to the tomato Blind protein (Sl Blind) were compared to three Blind-like sequences from tomato (Sl Blind-like1, 2, 3) and one sequence from potato (St Blind-like4) using the Clustal W software. Multiple sequence alignments were done using the option “Bootstrap Neighbour Joining Tree” with 1000 bootstraps. The sequence of At MYB87 was at the N-terminus extended by eight amino acids according to the sequence of EST DR750776. Amino acids that are conserved in at least 50% of the sequences are indicated in red. Conservative replacements are in blue, non-conservative replacements and non-conserved positions are in black. At: Arabidopsis thaliana, Sl: Solanum lycopersicum, St: Solanum tuberosum.
• Supplemental Figure 2 - RT-PCR analysis of rax alleles. Total RNA extracted from flower buds of the genotypes indicated above adjacent lanes was analyzed by RT-PCR using MYB gene specific primer combinations localized either 5’ (A) or 5’ and 3’ (B) of the T-DNA/En insertion point. In each case primer combination A led to the expected amplification product, whereas the primer combinations B yielded amplification products only when RNA from wild-type plants was used.
• Supplemental Figure 3 - Scanning electron microscopy (SEM) analysis of rax mutants. (A) SEM of an empty rosette leaf axil of a rax1-3 rax2-1 rax3-1 plant. (B) SEM of rosette leaf axil with an axillary bud of a Columbia wild-type plant. (C) SEM of an empty cauline leaf axil of a rax1-3 rax2-1 rax3-1 plant. CL: cauline leaf, RL: rosette leaf, ST: stem.
• Supplemental Figure 4 - Root development of rax1-3 mutants. Col and rax1-3 seeds were surface sterilized and germinated on MS medium. Plates were incubated in vertical orientation in a controlled environment room with 16 h light (8 h dark), 20 °C day temperature, 18 °C night temperature.
• Supplemental Figure 5 - Phenotypic analysis ofrax2-1 and rax3-1 plants. In comparison to the corresponding wild-types (A, C, C, F), the number of axillary buds developing from axils of rosette leaves and cauline leaves of rax2-1 (A, B) and rax3-1 (D, E) plants was not reduced.
• Supplemental Figure 6 - Semi-quantitative RT-PCR analysis of 35S:RAX2 plants. Total RNA extracted from selected F2 plants of independent transgenic lines (2711-2715) and a Columbia wild-type plant was analyzed by RT-PCR using the RAX2 specific primers 6922-1 and 6922-2. Amplification of actin cDNA was used to ensure that equal amounts of cDNA were added to each PCR reaction.
• Supplemental Figure 7 - In-situ hybridization analysis of RAX1 and RAX3 mRNA accumulation. (A, B) Longitudinal sections through vegetative shoot apices of 28-day-old rax1-3 (A) and las-4 (B) plants grown under short day conditions. (C) Longitudinal section through a shoot apex of a Columbia wild-type plant grown for 28 d in short photoperiods and subsequently for 12 d under long-day conditions. The section was hybridized with a RAX1 (A, B) or a RAX3 (C) antisense probe, respectively. Arrow heads point to RAX3 signals.