Transcription of selected auxin biosynthesis and GH3 genes in response to Ethrel in the 2011 trial. The expression of TAR1-TAR4, YUC1, GH3-1 and GH3-2 in pre-veraison Shiraz berries from the 2011 trial was analysed by qRT-PCR at the indicated time points after treatment with a Control or Ethrel solution (see Figure 1). Control, dark grey bars; Ethrel, light grey bars. All data represent means ± SE (n = 3). Asterisks indicate significant differences of the mean values of Ethrel-treated samples from the mean values of Control samples as determined with Student’s t-test (*p < 0.05, **p < 0.01).