FIGURE 5.

Effect of GA₃ application on VvDELLA accumulation in V. vinifera cv. Black finger (BF) and cv. Spring blush (SB). GA₃-induced degradation of VvDELLA1 and VvDELLA2 proteins in internodes (A), rachis (B), and pistils (C) of BF and SB collected during the 2010 growing season. Immunoblot analyzes of VvDELLA proteins in organs were carried out using protein-specific, affinity-purified, anti-VvDELLA polyclonal antibodies. Total proteins were extracted from organs treated for 6 h with GA₃ (G, 121 μM for rachis, and 90 μM for pistils). Control (C) samples were treated with Triton X-100 (0.025%). Physiological stage at which organs were treated is detailed in “Materials and Methods.” Recombinant full-length proteins (R.P.) (3.75 ng each of VvDELLA1 and VvDELLA2) were used as size controls. In all lanes except R.P., solid black arrows show band of interest, and Asterisked-bands indicate non-specific proteins detected by the anti-VvDELLA antibodies. Differences in sizes of R.P. and endogenous VvDELLA proteins result from tags on the R.P. Underlined numbers indicate intensity of bands relative to GA₃-treated samples as determined by ImageJ. Consistent results were obtained when the experiment was repeated during the 2011 growing season.