Fig. 8: Effects of ClCOMT1 overexpression on melatonin contents and abiotic stress tolerance in Arabidopsis.

A Schematic diagram of the pGREEN-ClCOMT1 vector. B RT-PCR analysis of ClCOMT1 expression in transgenic and wild-type (WT) Arabidopsis. C Melatonin contents in transgenic and WT Arabidopsis. D, E Phenotypes and survival rates of transgenic (line #4) and WT Arabidopsis after freezing, mannitol, or NaCl treatment. For freezing treatment, two-week-old Arabidopsis seedlings were exposed to −10 °C for 1 h, followed by recovery at 22 °C for 4 d. For drought and salt stress, Arabidopsis seeds were sown and grown on ½ MS containing 250 mM D-Mannitol and 75 mM NaCl, respectively. In (C, E), values are means ± SD (n = 3). Asterisk (*) indicates significant difference at P < 0.05. CK, control check; ClCOMT, Citrullus lanatus caffeic acid O-methyltransferase