Real-time reverse transcription-polymerase chain reaction (RT-PCR) validation of three differentially accumulated barley transcripts related to density stress at three time points. Microarray expression data for Steptoe at 15 d after germination is also shown. Relative expression is displayed in log2 values. Positive numbers indicate upregulation from the low density to the high density, whereas negative numbers indicate downregulation from the low density to the high density. Transcripts analyzed are contig14901_at (auxin-responsive protein), contig1689_at (lipid transfer protein [LTP]), and contig6484_at (NAC domain protein).