Fig. 1.

AR formation from hypocotyls of Arabidopsis thaliana seedlings, Col-0 ecotype, at the end of in vitro culture growth (22 DAS) under continuous darkness either in the absence of exogenous hormones (0, HF) or with different concentrations of ACC. (A), Mean hypocotyl length (±SE). (B) AR density, i.e. AR number per cm of hypocotyl, expressed as the mean value (±SE). (C) Percentage of seedlings with ARs. n=30. a, b, P<0.01 differences with respect to the other treatments; c, P<0.05 difference with respect to HF; d, P<0.01 difference with respect to 0.01 µM ACC; e, P<0.01 difference with respect to HF and 0.04 µM ACC. Columns with the same letter or no letter are not significantly different. Similar results were obtained with the Col ecotype.