Figure 3.

MYB33 is strongly repressed by miR159 in vegetative tissues. A to D, Histochemical staining for GUS activity in 14-d-old seedlings of MYB33:GUS after 5 d of staining (A and B), mMYB33:GUS after 16 h of staining (C), and wild-type Columbia-0 (Col-0) after 5 d of staining (D). Bars = 100 μm (A) and 200 μm (B–D). E, Levels of MYB33:GUS (MYB) and mMYB33:GUS (mMYB) mRNA in five independent lines detected by qRT-PCR. F, GUS activity in five independent MYB33:GUS and mMYB33:GUS averaged lines. Error bars represent sd. G, Illustration depicting the positions of the primers used to quantify the mRNA of the transgenes. The primers span the miRNA target site of the MYB33:GUS construct and therefore only detect uncleaved mRNA.