Fig. 2

In situ hybridization for OsAS1 in the basal portions of wild-type and gs1;2 mutant shoots. Longitudinal sections of basal portions of shoots were prepared from the wild-type rice (WT) (a, c, d, f, g, i) and from gs1;2 mutants (gs1;2) (b, e, h) grown hydroponically in the presence of 1 mM NH₄Cl until the fourth-leaf stage. A sense probe was hybridized to WT sections (c, f, i) as a negative control. Red arrowheads indicate hybridization signals for OsAS1 transcripts in the shoot apical meristem (SAM) (a, b), phloem companion cell of the nodal vascular anastomoses (cc) (d, e), an immature leaf (IML) area (a, b, g, h), and the tiller containing the axillary bud meristem (AM) (g, h). Note that the signal intensity in gs1;2 (e) was far weaker than in the WT (d). Scale bars = 100 μm (a - c, g - i) and 50 μm (d - f)