T-DNA insertion site and affected genes in sk156 mutant. (A) Southern blot analysis of sk156 showing a single T-DNA insertion. Lane 1, digested with BamHI. Lane 2, digested with HindIII. (B) Schematic of T-DNA inserted in the third intron of bHLH069 shown by ‘∇’ (empty triangle). Boxes, exons; Lines, introns and intergenic regions. Thick grey arrows show promoter regions and their transcription direction. (C) Transcript levels for miR156b and unknown RNA gene (AT4G30975) in sk156 relative to WT (set at 1) using qPCR. (D) Transcript levels for bHLH069 in sk156 relative to WT (set at 1) using qPCR. A Duncan's multiple range test in (C) and (D) showed significant differences of the means (± standard deviation) between sk156 and WT Col-4 at p < 0.01 (**) and p < 0.05 (*).