Fig. 6

ttl1–1 and b1l exhibited promoted seedling development under cold conditions, and BR restrained the promoted hypocotyl length of b1l mutants under cold conditions. a Hypocotyl growth of 2-week-old wild type and ttl-1 seedlings under cold conditions in the dark. b Hypocotyl growth of 2-week-old wild type and ttl-1 seedlings under cold conditions in the dark. Seedlings in (a) and (b) were germinated and grown on MS plates at 12 °C for 24 h in the dark. Each data point is expressed as the mean value ± SEM (n = 24). Asterisks indicate significant differences (*p < 0.05) compared with the wild type. c Hypocotyl growth of 2-week-old wild type and b1l seedlings with BR treatment in the dark under cold conditions. Seedlings were germinated and grown on MS plates containing increased concentrations of brassinazole at 12 °C in the dark conditions. Each data point represents the mean value ± SEM (n = 24). Asterisks indicate significant differences (*p < 0.05) compared with the wild type at each brassinolide concentration