Figure 6.

Analysis of GS₁ transcripts in the roots of soybean plants treated with hydrogen peroxide and ammonium nitrate. Soybean plants (18 d after planting) were either fed 10 mm KCl (K) or 10 mm ammonium nitrate (N) or allowed to take up 0.1% hydrogen peroxide (H) for 3 d. The roots of the 21-d-old plants were harvested, and the total RNA was isolated. The data from a representative experiment are shown here. A, RNA (20 μg) from each sample was then subjected to electrophoresis in a formaldehyde-agarose gel. The gel was blotted onto nitrocellulose and probed with the coding region of pGS100, the 3′-untranslated region of the ammonia-inducible gene (pGSGmD3′) or the 28S rRNA gene of soybean. B, Hybridization signals were quantified using Intelligent Quantifier software, and the values obtained with the two GS probes were standardized against the values obtained with the rRNA gene probe and plotted.