Design of artificial microRNA transgene constructs and relative expression of BdCAD1 and BdCOMT4 in transgenic plants. Artificial microRNA (amiRNA) constructs were designed to target and silence the (A) BdCAD1 and (B) BdCOMT4 transcripts. Exons are indicated by solid black boxes, untranslated regions by grey boxes, and intron by thin, black lines. The genes are drawn to scale. Arrows indicate the artificial microRNA target regions. RNA was prepared from stems of developmentally equivalent transgenic and empty vector control plants and subjected to quantitative real-time PCR to assay for target gene expression. Relative expression of (C) BdCAD1 and (D) BdCOMT4 with control housekeeping gene Bradi5g25870. The boxes show interquartile range, the whiskers show the outer quartile edge, and the black line represents the median of each distribution. Open circles represent outliers, when present. * Denotes significance at the 5% level.