Figure 1. Elongation of adventitious roots and viability of adventitious root tips in wheat seedlings. (A) Growth conditions. Eleven-day-old aerobically-grown wheat seedlings were transferred to aerated nutrient solution with or without 20 μM ACC. After 2 d, these seedlings were transferred to stagnant solution and grown for 3 d. While 9-d-old wheat seedlings were transferred to stagnant solution and grown for 7 d. Stagnant solution contained 0.1% (w/v) dissolved agar and was deoxygenated (dissolved oxygen, < 0.5 mgL⁻¹) prior to use by flushing with N₂ gas. The broken line with the asterisk indicates when the emergence of the first adventitious roots was observed (day 10). (B) Elongation of adventitious roots during 3 d growth under stagnant conditions (from day 13 to day 16). (C) Cell viability (TTC reduction) in adventitious roots at 0 to 10 mm from the root tips of the wheat seedlings immediately after 3 d growth under stagnant conditions (day 16). The methods are described in more detail by Yamauchi and colleagues.¹² Values are means (n = 5) ± SD. Different lower-case letters denote significant differences among the conditions (P < 0.05, one-way ANOVA and then Tukey’s test for multiple comparisons). -ACC; the -ACC seedlings, +ACC ; the +ACC seedlings, STAG; the STAG seedlings, TTC; 2,3,5-Triphenyltetrazolium chloride.