Comparison of the submergence response of deepwater and lowland rice seedlings. Dark-field images with hybridization signals as white spots. Longitudinal sections through immature stems of rice cv Plai Ngam (upper row, A–E) and rice cv IR36 (middle row, F–J) were hybridized with an antisense OS-ACS5 probe. Time of submergence: 0 h (A and F), 4 h (B and G), 2 d (C and H), 7 d (D and I), and 14 d (E and J). K–N represent close-ups of marked zones corresponding to B, G, D, and I, respectively.