Figure 3.

med20a affects the transcription of MIR genes. (A) The accumulation of six pri-miRNAs was determined by real-time RT–PCR in Col and the med20a mutant. Total RNAs were extracted from inflorescences. The pri-miRNA levels were normalized to those of UBQ5 and compared with Col. Standard deviations were calculated from three technical replicates. Three biological replicates yielded similar results. (B) GUS expression driven by the MIR167a promoter was monitored in isogenic Col and med20a transgenic lines through GUS staining. GUS expression in old flowers was reduced in med20a compared with Col (arrows). (C) The accumulation of GUS mRNA from the lines in (B) was determined by real-time RT–PCR. The GUS mRNA levels were normalized to those of UBQ5 and compared with Col. Standard deviations were calculated from three technical replicates. Two biological replicates yielded nearly identical results.